Investigating the potential risk factors related to residual infections of Schistosoma japonicum in the

endemic areas of Bohol, Philippines

Clarence Londres de Guzman

This scholarly paper has been submitted in partial fulfillment of the requirements for the Degree of Master of Science (M.S.) in Global Health at Georgetown University

January 18, 2016

cld73@georgetown.edu

TABLE OF CONTENTS

ACKNOWLEDGEMENTS ........................................................................................................ iii

ACRONYMS AND ABBREVIATIONS .................................................................................... iv ABSTRACT ................................................................................................................................... v

INTRODUCTION ......................................................................................................................... 1 BACKGROUND & SIGNIFICANCE ........................................................................................ 2

Schistosomiasis in Bohol ........................................................................................................................ 2 Demographic and Socioeconomic Factors ............................................................................................ 4 Health Infrastructure and Personnel .................................................................................................... 4 Disease Status .......................................................................................................................................... 5

RESEARCH QUESTION ............................................................................................................ 5 Research Objectives ................................................................................................................................ 6

LITERATURE REVIEW ............................................................................................................ 7 Overview of schistosoma parasites and intermediate snail vectors ................................................... 7 History of schistosomiasis control in the Philippines .......................................................................... 8 The Health System: National & Local Levels .................................................................................... 10 DOH’s 4-Pronged Approach ............................................................................................................... 12

METHODS .................................................................................................................................. 13 Design Overview ................................................................................................................................... 13 Data: Context, Population, and Sampling .......................................................................................... 14 Dependent Variable .............................................................................................................................. 15 Key Independent Variables ................................................................................................................. 16 Basic Conceptual Framework ............................................................................................................. 16 Estimation Approach & Data Analysis .............................................................................................. 16 Procedures ............................................................................................................................................. 17

RESULTS .................................................................................................................................... 19

DISCUSSION .............................................................................................................................. 26 Mass Drug Administration .................................................................................................................. 26 Vector Control ...................................................................................................................................... 28 Environmental Sanitation .................................................................................................................... 30 Safe Water Supplies .............................................................................................................................. 31 Advocacy and Health Education ......................................................................................................... 33 Other Determinants .............................................................................................................................. 34

CONCLUSION ........................................................................................................................... 36 Design Critique & Limitations ............................................................................................................ 36 Current Needs & Future Outlook ....................................................................................................... 36 Recommendations for Future Study & Final Remarks .................................................................... 37

REFERENCES ............................................................................................................................ 39

APPENDIX .................................................................................................................................. 42

iii

ACKNOWLEDGEMENTS

This research project is part of the National Schistosomiasis Control and Elimination Program’s

(NSCEP) routine monitoring and evaluation activity for schistosomiasis in the province of

Bohol. The Malaria, other Vectorborne and Parasitic Diseases (MVP) Unit of the World Health

Organization Representative Office in the Philippines has collaborated with the Department of

Health to plan and successfully carry out this project.

The following individuals and their respective staff have provided great support and significant

contributions towards the completion of this study:

Team Leader: Dr. Winston A. Palasi, NSCEP

Team Members from the Philippines

Dr. Joanri T. Riveral and Staff, Regional Health Office, Region VII

Dr. Reymoses A. Cabagnot and Staff, Provincial Health Office, Bohol

Dr. Francisco Ngoboc and Staff, Municipal Health Office, Talibon

Dr. Analita N. Auza and Staff, Municipal Health Office, Trinidad

NDP Nurses Talibon

NDP Nurses Trinidad

Department of Education Representatives

Department of Agriculture Representatives

WHO

Dr. Zaixing Zhang, WHO Philippines Country Office, MVP Unit

Volunteer

Ragine Valente, Municipal Nurse, Cavinti, Laguna

iv

ACRONYMS AND ABBREVIATIONS

BBC Behavior Change Communication

BHW Barangay (Village) Health Workers

BHS Barangay Health Station

DALYs Disability-Adjusted Life Years

DMO Development Management Officer

DOH Department of Health

ELISA Enzyme Linked Immunosorbent Assay

EPG Eggs Per Gram of feces

IEC Information, Education, Communication

IRA Internal Revenue Allotment

KAP Knowledge, Attitude and Practice

LGU Local Government Unit

M&E Monitoring and Evaluation

MDA Mass Drug Administration

MHO Municipal Health Office(r)

MSI Municipal Sanitary Inspector

MVP Malaria, other Vectorborne and Parasitic diseases unit

NIA National Irrigation Administration

NDP Nurse Deployment Program

NSCEP National Schistosomiasis Control and Elimination Program

PHN Public Health Nurse

PHO Provincial Health Office(r)

PPE Personal Protective Equipment

PSI Provincial Sanitation Inspector

RHM Rural Health Midwife

RHO Regional Health Office

RHU Rural Health Unit

WHO World Health Organization

v

ABSTRACT

The province of Bohol in the Philippines’ Region VII has had two endemic areas for

schistosomiasis. However, recent national surveys and reports have suggested that those two

municipalities, Talibon and Trinidad, are near elimination levels for the disease. According to a

2009-2014 Sentinel Surveillance Report, Bohol has consistently reported virtually zero cases of

active or heavy infections for schistosomiasis.15 With a prevalence rate of less than 1%, Bohol

has essentially reached the category of elimination level. In addition, a recent snail survey

conducted in 2013 by the University of the Philippines, Los Baños research team has indicated

zero infection rates for the known intermediate hosts.10 Such findings corroborate the province’s

asserted status of having eliminated the disease as a public health concern. However, a more

recent assessment by Belizario, et al. (2015)16 revealed that there is still a significant amount of

residual infections for schistosomiasis in the province.

This project documents and examines the current strategies, particularly the major public

health interventions and programs that have contributed to the reduced prevalence rates of

schistosomiasis in the region over the last five years. The main objective of this study, which

entails a qualitative research component, is to better assess the validity of the aforementioned

surveillance reports. Furthermore, through a quantitative research approach, and given the

persistent presence of residual infections, this paper aims to provide verifiable evidence and

specific clues for future recommendations on elimination and control efforts. A nested case-

control study design is used to determine the relationship between risk factors and residual

infections of schistosomiasis in Bohol. The results indicate a validation of the integrative multi-

component approach currently being implemented in the province, with an emphasis being

placed on access to potable water, sanitation infrastructure, animal vector control, and health

education in schools.

1

INTRODUCTION  

Schistosomiasis, also known as bilharzia, is a

parasitic disease that currently infects over

200 million people worldwide, resulting in the

loss of approximately 25 million disability-

adjusted life years (DALYs).1, 2 Although it

has a relatively low mortality rate, with

estimates ranging from as low as 10,000 and

up to 200,000 deaths annually, it ranks only

second to malaria in the number of

individuals infected and at risk for the

disease.3 It remains a significant public health

concern in 78 countries, with endemicity

established in regions of Africa, East and

Southeast Asia, the Pacific Islands, Brazil,

and the Caribbean Islands. Among those, the

disease inflicts the heaviest burden in Sub-

Saharan Africa, accounting for roughly 77%

of the total number of DALYs globally.4, 5

The World Health Organization classifies

schistosomiasis as “a disease of poverty that

leads to chronic ill-health.” 6 Infections in

humans elicit various symptoms, depending

on the severity and developmental stage of the

disease. This may include cognitive disability

in children, nutrient and energy deficiencies,

as well as liver fibrosis.4 The presence of

worms, compounded with reactions to the

eggs produced by adult female worms, comes

with considerable immunologic and energetic

consequences.4 As a result, the human host

experiences an array of functional deficits.

The individual’s immune system, duration of

disease pathogenesis, infection intensity, and

location of egg deposition in the body are

some of the major factors that determine the

severity of the disease.1, 4 On a population

level, researchers typically measure the

severity of the disease by looking at the

prevalence, intensity (mean EPG in feces),

and incidence in a given year.4 These metrics

are then integrated and correlated to estimate

disease transmission and contamination

potential in a given population or area.

Although prevalence and intensity of

infection usually vary with age, its general

pattern shows more intense infections and

higher prevalence rates as age increases up to

the teenage years, after which these rates

begin to decline.4, 6

There are five known blood fluke species of

the genus Schistosoma that cause the disease

in humans: S. mansoni, S. japonicum, S.

mekongi, S. intercalatum, and S.

haematobium. For endemic areas where S.

japonicum and S. mekongi are found, zoonotic

transmission makes control measures

especially even more challenging.1 S.

japonicum is mainly endemic in Asian

2

countries including China, Indonesia, and the

Philippines. In the Philippines, the disease is

currently endemic in 12 regions, 28

provinces, 14 cities, 203 municipalities and

1,593 barangays.10, 11 This places more than

12 million people at risk for the disease, of

which approximately 2.5 million are directly

exposed.10, 12 The Philippine Department of

Health’s Disease Prevention and Control

Bureau established the National

Schistosomiasis Control and Elimination

Program (NSCEP) in order to address this

issue. The program has been working closely

with the World Health Organization to

formulate public health strategies, implement

effective interventions, and develop technical

guidelines and tools for its control and

successive elimination in the future.

When considering the most effective

measures for disease prevention and control,

studies have shown that the optimal approach

is to break the S. japonicum lifecycle through

a multi-component integrated control.1 In

essence, this scholarly paper is a case study

that aims to validate such claim by examining

the major contributing factors to the

successful development of disease control and

elimination currently and notably taking place

in the province of Bohol, Philippines. By

designing and conducting an investigation

regarding the potential risk factors related to

residual infections of the disease in the

province, its main purpose is to provide

important clues and lessons for future

directions on how to effectively control and

eliminate schistosomiasis in other parts and

even more highly endemic areas of the

Philippines.

BACKGROUND & SIGNIFICANCE

Schistosomiasis in Bohol

Bohol is an island province located in the

country’s Region VII group of islands. (See

map: Appendix, Figure 2A) Schistosomiasis

is considered endemic in 2 of Bohol’s 47

municipalities, namely Talibon and Trinidad.

The two adjacent municipalities are located

on the northeastern coast of the island.

Within each municipality, there are four

barangays (the smallest administrative

division in the country) where schistosomiasis

is endemic.

Talibon is a 1st class income municipality

with a population of 64,761. It has a total

land are of approximately 22,400 hectares and

is consisted of 25 barangays, 8 of which are

3

islands.17 Its major industries include farming,

fishing, cottage industries, mining, and auto

repair shop. Its major products include rice,

fish, corn, seaweeds, copra, hat and mat.17

The four schistosomiasis-endemic barangays

are San Agustin, San Carlos, San Jose, and

San Roque. (See map: Appendix, Figure 2B)

Trinidad is a 3rd class income municipality

with an estimated population of 30,104.18 It

has a total land area of 15,211 hectares and is

consisted of 20 barangays.18 Like Talibon, it

is considered an agricultural community

where farming is the predominant occupation.

The four schistosomiasis-endemic barangays

are Kinan-oan, Mabuhay Cabiguhan, San

Vicente, and Santo Tomas. (See map:

Appendix, Figure 2C)

Since 1988, the efforts have been focused on

the eight endemic barangays of the two

municipalities. The Department of Health

Regional Office (Region VII) initially

established a Schistosomiasis Control Team

Office to oversee both municipalities. The

advantage of being geographic neighbors

allowed Talibon and Trinidad to collaborate

and integrate their meetings, activities and

plans of action to address their common

health problem.19 As a result, it fostered a

symbiotic relationship between the two

municipalities that strengthened their efforts

and encouraged inter-communal development

projects to combat schistosomiasis. Activities

such as active case finding through stool

collection from the general population of the

endemic barangays and treatment of positive

cases were conducted on a regular basis.19

Moreover, quarterly surveys of snail site

colonies were done and when necessary,

clearing and mollusciciding activities were

carried out. Continuous sanitary toilet

construction and advocacies on toilet

utilization were also prioritized, especially at

the local barangay levels. Many of such

health promotional campaigns were

concentrated in public schools of the endemic

barangays, in full coordination with the

Department of Education.20

After 2008, however, with the national

implementation of Mass Drug Administration

(MDA) for praziquantel, active case finding

was no longer practiced. Patients from

endemic barangays sought consultations at the

RHUs for examinations.18 Specifically, a

medical technologist, either locally trained or

as assigned by the MHO (e.g. a ‘visiting’

med-tech), would perform a parasitological

test, which is a stool exam via a Kato-Katz

technique, and the subsequent diagnosis for

schistosomiasis. MDA to schoolchildren in

4

the endemic barangays was initiated in 2009

and annually until 2013. Due to a

miscommunication, the two municipalities

had assumed that the protocol for MDA as set

by the national Department of Health was to

complete a consecutive 5-year period of

implementation.19, 20 Thus, MDA was not

carried out in 2014. With further clarification

and instruction from DOH, MDA was deemed

mandatory until a complete assessment and

comprehensive evaluation of the endemic

areas proved otherwise. As such, even with

already low prevalence rates and incidence

for schistosomiasis, both Talibon and

Trinidad resumed MDA activities in 2015.

Demographic and Socioeconomic Factors

Across all endemic barangays, the percentage

of school-age children (6-16 years old)

account, on average, for about 20% of the

total population.17, 18 This is currently the

target population for MDA in the two

municipalities, since they are considered

among the most at-risk groups in the

population for schistosomiasis. Farmers and

fishermen are also among those at-risk, and

they constitute approximately 20-30% of the

population in Talibon and Trinidad.17, 18

Those are significant numbers when

considering the economic impact and burden

of the disease. The main source of income is

from the agricultural sector and it places a

huge financial burden on the communities if

those workers are incapacitated due to health

problems. A study in Cambodia has found

that the return investment for each dollar

invested for the schistosomiasis control

program yields US$ 3.84, while the cost per

death avoided amounts to US$ 6,531, a hefty

sum in comparison to cost-effective public

health interventions that the government

could potentially invest in.2

Health Infrastructure and Personnel There is currently one provincial hospital

(Garcia Memorial Provincial Hospital) in

Talibon that serves the surrounding

municipalities in the region. Both Talibon

and Trinidad have a Municipal Health Center,

supervised by the MHO. There are 26

barangay health stations in Talibon and 20 in

Trinidad, both of which employ municipal

nurses (3-5 per RHU) and midwives (1 per

barangay).17, 18 For each RHU, there is one

public doctor, one medical technologist (or

microscopist), one sanitary inspector, and a

number of barangay health workers (BHWs)

assigned in each barangay. The Nurse

Deployment Program (NDP) has provided

5

about 10 nurses per RHU, and function under

the direction of the MHOs.17, 18

Disease Status

To date, schistosomiasis is still considered

endemic in the two municipalities. However,

in Trinidad, no human cases have been

recorded since 2007. Talibon on the other

hand, reported two consultation cases in 2014

that have histories of schistosomiasis from

Mindanao, the Philippines southern group of

islands wherein schistosomiasis remains the

most heavily endemic. After a series of

diagnostic tests, only one was found to still be

positive for the disease and was immediately

referred for treatment. The other patient

tested negative via Kato-Katz and was given a

single dose of praziquantel. In 2015, another

consultation case indicated a history of

schistosomiasis from Mindanao, but was later

diagnosed negative for the disease based on

Kato-Katz.17, 18

In Trinidad, there are approximately 6,000

people directly at risk for the disease, while

Talibon accounts for another roughly 15,000

inhabitants at risk. Direct sources of

transmission are from the nineteen snail-

infested bodies of water where O. quadrasi

colonies have been found.22 The latest snail

survey conducted in 2013 by the University of

the Philippines, Los Baños Research Team

showed zero infection rates of S. japonicum

among snails collected from those sites.

However, a recent national assessment in

2014 confirmed that a significant number of

residual infections of schistosomiasis still

exist among school-age children from the two

endemic areas of Bohol.

RESEARCH QUESTION

As previously mentioned, the province of

Bohol has two known endemic areas for

schistosomiasis. However, national surveys

and reports have suggested that those two

municipalities, Talibon and Trinidad, are near

elimination levels for the disease. According

to the 2009-2014 Sentinel Surveillance

Report, Bohol has consistently reported

virtually zero cases of active or heavy

infections of schistosomiasis.15 With a

prevalence rate of less than 1%, Bohol has, in

theory, reached the category of elimination

level for an endemic area as categorized by

the national DOH office.15 Furthermore, a

recent snail survey conducted in 2013 by the

University of the Philippines, Los Baños

research team has indicated zero infection

rates for the known intermediate snail hosts.15

6

Such findings corroborate the province’s

asserted status of having eliminated the

disease as a public health concern.

In 2014, however, Belizario’s Assessment of

schistosomiasis endemic areas through

parasitological and serological techniques,

(Belizario, et al., 2015) indicated that there

are still in fact a significant number of

schistosomiasis infections in the province.

Serological tests via ELISA Antibody and

ELISA Antigen confirmed the presence of

these residual infections. Thus, the goal of

this study is to investigate why those

infections still exist despite initial surveillance

reports that have stated otherwise. Since

current public health intervention programs

are already in place and have been proven to

successfully reduce prevalence rates, this

research specifically explores those major

contributing factors and how exposure rates to

a particular ‘intervention’ are related to risk

factors for disease infection.

Research Objectives This project aims to describe the current

strategies, particularly the major public health

interventions and programs that have

contributed to the reduced prevalence rates of

schistosomiasis in Bohol, particularly over the

last five years, essentially alleviating the

heavy burden of the disease in the region.

More importantly, it entails an analytical

research component done via a mixed

methods approach (i.e. qualitative and

quantitative research) to better assess the

validity of the initial surveillance reports, as

well as to investigate the potential risk factors

related to the residual infections. The

analytical research component involves a

follow-up assessment of Belizario’s study

conducted in 2014, which included samples

collected from school-age children in Talibon

and Trinidad.16 Using the selected sample

from this previous study, a qualitative study

on schistosomiasis in the two endemic

municipalities using a nested case-control

study design is applied. By collecting school-

based data and evaluation surveys, the goal of

the study is to investigate the potential risk

factors related to residual infections of

Schistosoma japonicum at the individual

level.16 The quantitative analytical

component, which utilizes statistical

techniques, could thereby validate current

public health records and surveillance data of

disease status in the community. In doing so,

the study intends not only to extract key

lessons from the case of Bohol, but given the

existing presence of residual infections, to

also provide a feasible course of action and

7

strategies in confronting these persistent

infections moving forward.

LITERATURE REVIEW

Considered a neglected tropical disease,

schistosomiasis is both an environmental

disease and a disease of poverty. It is an

environmental disease because

“anthropogenic and natural parameters

influence the distribution of the parasite

population in aquatic systems by defining the

ecological niches where the snail intermediate

hosts can survive.” 4 In addition, the disease is

transmitted from the final vertebrate host to

the aquatic environment through urinary and

fecal contamination of bodies of water,

including artificial waterways.4 It is a disease

of poverty because “its geographic

distribution reflects a community’s access to

safe water, sanitation infrastructure,

socioeconomic status, and access to

medication.”4 Praziquantel, currently the

standard drug used to treat schistosomiasis, is

an anthelmintic that kills the adult worms

inside the final human host. Although this

drug has been effective in decreasing

morbidity in many endemic regions, studies

have shown it to be an unsustainable option

for treatment because it lacks the capacity to

address the issue of parasitic risk in the

environment.4, 7 Bodies of evidence suggest

that elimination of schistosomiasis using

MDA as the major approach will not be

sustainable in the long run. One study, for

example, examined the long-term impact of

intensive case finding using praziquantel as

treatment, supported by a compliance rate of

more than 80% during the 10-year lifespan of

the study. Despite significant reductions in the

prevalence rates and incidence of infections

that occurred in the subsequent 3 to 4 years, it

was immediately followed by marked

rebound rates for the disease.8, 9

Overview of schistosoma parasites and intermediate snail vectors

Schistosomiasis in the Philippines is caused

by an infection of the blood fluke

Schistosoma japonicum.3 To complete their

zoonotic life cycle, schistosome parasites

infect an intermediate snail host and a final

vertebrate host (i.e. humans). Schistosome

ova pass from the mammalian host to the

environment via fecal matter and remain

viable for up to seven days. Upon contact

with freshwater, the embryonated eggs hatch

and release free-swimming, sexually

differentiated miracidia that infect the

intermediate snail host Oncomelania hupensis

quadrasi. 4 The miracidia then asexually

8

reproduces through a series of stages called

sporocysts, generating juvenile cercariae, the

infective larval stage for humans. The

cercariae penetrate human skin, lose their tail

thereafter, and become schistosomula that

migrate through the blood stream via the

lungs, onto the heart, and finally to the liver,

where they mature and mate for life.1 They

produce eggs that the animal host, if left

untreated, will repeatedly shed back into the

environment, ultimately restarting the

schistosome life cycle. On average, the adult

worms can produce up to 3,000 eggs per day,

making it the most pathogenic among the

schistosoma species.3

History of schistosomiasis control in the Philippines

In 1906, the first case of schistosomiasis in

the Philippines was reported. The following

describes the account and discovery of this

significant index case in the country:

“The [patient] was a Filipino man who had

never been out of the country. He eventually

died with clinical impressions of amebiasis

and bacterial infection. Autopsy confirmed

the diagnosis of amebiasis, but with additional

findings of Schistosoma ova in sections of the

large intestine, liver, and lungs.

Subsequently, schistosome ova were found in

several cases among 500 autopsies reported in

1908 and in the feces of some prisoners

admitted to Bilibid Prison, in the City of

Manila in 1914. Several years later, in 1928,

a case of Katayama disease (a toxemic

syndrome with fever in the acute, early egg-

laying phase of schistosomiasis) presenting as

chronic appendicitis was reported. Attempts

to demonstrate the intermediate host of the

parasite were not successful until the

discovery of the snail Oncomelania hupensis

quadrasi in Palo, Leyte in 1932.” 1

Despite research disruption due to Word War

II, the disease gained further attention when

in 1945, an outbreak in Leyte occurred among

Americans and the Allied Armed Forces. In

1953, the Philippines finally recognized

schistosomiasis as a public health concern.

Extensive research activities such as studies

on parasite biology, transmission, and control

to clinical and pathological aspects of the

disease were conducted. In 1975, S.

japonicum endemic regions were identified,

with an estimated 5 million people living in

those endemic areas and over 800,000

individuals with active infections. This

included the island of Bohol, with the major

foci of the disease located in the islands of

Leyte, Samar, and Mindanao, a situation that

largely remains today. These endemic

9

regions have no distinct dry season, and

predominantly comprised of rice growing

areas, which maximizes the physical contact

between humans and the intermediate hosts,

O. quadrasi snails.1

The disease threat of schistosomiasis to public

health proved to be a daunting one. Climatic

conditions and rice farming methods have

made vector control difficult. Prior to the

introduction of praziquantel in the

Philippines, different methods were used in an

attempt to decrease transmission by reducing

O. quadrasi snail populations and by

preventing human exposure to the infective

form of the parasite (i.e. cercariae).

Environmental engineering, such as improved

irrigation systems, along with the use of

molluscicides was utilized.1 Unfortunately,

these approaches were expensive and had

only yielded very limited results in lowering

human transmission rates. Another

component of the program was to provide and

encourage better sanitation. However, this

also became more difficult to sustain with

time, especially in rural and impoverished

communities, where very little of the

populations had access to sanitary toilets.

Furthermore, preventive chemotherapy was

only used on a case-by-case basis, as the

available medications caused side effects

before therapeutic levels were even reached.1

Thus, even though the early public health

intervention programs of the time ultimately

resulted in positive health outcomes, they

were clearly not effective enough in reducing

the prevalence, incidence, or morbidity of S.

japonicum infections in the country.

Praziquantel was first introduced in the

Philippines in 1980, which led the national

schistosomiasis control program to transition

to a chemotherapy-based program. Case

finding and treatment also continued to

contribute in lowering national prevalence

rates for the disease. By 1990, the Philippine

National Schistosomiasis Control Program

(PNSCP) had gained enough funding, mainly

through a substantial loan, which enabled

them to intensify active case finding and

treatment in all endemic areas.1 The country

had been reporting at least a 10% national

prevalence rate prior to this, but by 1995, this

figure was reduced to less than 5%.13

However, subsequent marked budget cuts

resulted in reduced financial support and the

loss of schistosomiasis control teams in each

of the endemic municipalities. After 1995,

the chemotherapy-based control program then

shifted from case finding and treatment to

Mass Drug Administration (MDA). Despite

the decrease in financial manpower support

10

for the control program, the annual national

prevalence data on schistosomiasis in the

Philippines reported by the PNSCP had been

seemingly maintained at less than 5%. This

reportedly low national prevalence data had

given the idea that schistosomiasis was not a

major public health concern anymore and

could even be soon eliminated in some

endemic areas via MDA alone.1, 13 However,

as indicated by previous studies regarding

underestimation of prevalence rates, many of

those areas experienced significant rebound

rates for schistosomiasis infections.21 The

following decade ushered in a new era for the

Department of Health with the National

Schistosomiasis Control & Elimination

Program (NSCEP). It called for a more

sustainable and integrative approach to

disease control, especially at the local levels

of the endemic regions. MDA was still very

much part of the big picture, and has been

strongly supported by international

organizations such as the WHO.

Nevertheless, there is still clearly a great

demand for more action from the government

side and a better response from the public to

solve the problem of schistosomiasis in the

Philippines. (See Figure 1 in Appendix for

diagram of the historical evolution of

schistosomiasis control in the Philippines)

The Health System: National & Local Levels As shown in Figure 3A (Appendix), the

National Schistosomiasis Control &

Elimination Program (NSCEP) operates

under the Elimination Division for Neglected

Tropical Diseases, which is part of the

Infectious Diseases Office (IDO) of the

Disease Prevention & Control Bureau within

the Department of Health. Currently, NSCEP

collaborates with the WHO, which provides

technical assistance for the national program,

including drafting policies, guidelines, and

planning to help achieve their objectives and

support the national program agenda. The

partnership maintains a clear understanding of

their respective roles, wherein the WHO

serves to fortify the national office and its ties

with the international community; namely,

China, in its most recent technical cooperation

agreement on schistosomiasis, given that the

two countries share the same type of species

for the disease.

The main challenge for the DOH national

office is the implementation and management

of the program at the local levels. The

country’s political structure is devolved,

making it a decentralized health system that

completely functions at the national, regional,

and provincial levels, but not at the municipal

11

level, where the LGUs have full authority and

control of how to conduct and implement

public health programs (refer to Figure 3B,

Appendix). DOH advises, provides technical

guidance, and supports the LGUs as they see

fit, but ultimately, the LGUs make the final

decisions on how to run and manage their

programs. Such arrangement can create a

potential ‘disconnect’ between the central

DOH office and the LGUs, especially in

prioritization and supervision of any given

program. The process and flow of

information, for example, comes to a halt at

the municipal level, which can then either

fully digest or reject it. Theoretically, LGUs

will implement health programs from the

DOH and carry out the design and strategies

in full cooperation. However, LGUs may

recognize other programs to be more

beneficial to their communities and therefore

focus their efforts on those more than others.

Thus, it is important that in working with

LGUs, to build stronger relationships by

maintaining open lines of communication and

a mutual understanding of how to best serve

the people. This relationship is key to

fostering effective implementation and

realizing program objectives, such as those of

the NSCEP. In Bohol, both LGUs, with the

health sector operating under the MHOs of

Talibon and Trinidad, have established a solid

relationship with DOH. This is manifested

through the current state and several avenues

of the local public health sector, including

recent health indicators for schistosomiasis.

At the local level, the Municipal Health

Officer (of the MHO or also referred to as the

RHU) operates and directly reports to the

Municipal Mayor’s Office. The MHO

typically employs a number of municipal

nurses, a public health nurse (PHN), a

municipal sanitation inspector (MSI), a

microscopist (or a visiting medical

technologist from PHO), and rural health

midwives (RHM). In addition, the DOH has

established the Nurse Deployment Program

(NDP), which hires nurses, usually recruited

locally, and assigns them to the MHO, which

designates them for various duties, such as

supplementing a barangay health station,

where a midwife is typically in charge. (refer

to Figure 3C, Appendix)

The DOH assigns a Development

Management Officer (DMO), who serves as

the DOH Representative to the MHO. The

DMO is also responsible for the NDP nurses

working at the MHO. There is also a

Provincial Sanitation Inspector (PSI) from the

PHO, who works in partnership with the

DMO and supervises the MSI. Other

12

positions within the RHU are contracted by

the MHO, as necessary and as the LGU

budget permits. The organizational system in

Talibon and Trinidad follows this precise

structure, with well-defined responsibilities

and properly delegated tasks. The RHUs

work fluidly with the DMO in ensuring that

program objectives are carried out and

constant communication from the PHO, RHO,

and central DOH office is maintained. In

both Talibon and Trinidad, the MHOs are

very supportive of the national programs,

especially that of the NSCEP. They make the

necessary adjustments to adapt the programs

to their localities based on needs, but their

support and advocacy for a program such as

the NSCEP is clearly palpable in their routine

activities and health service provisions related

to schistosomiasis. In essence, the MHO

serves as the bridge between the LGUs and

the central DOH office, making it a crucial

position that defines the success of any given

public health program in the province.

DOH’s 4-Pronged Approach The newly reorganized NSCEP has outlined

specific areas of prioritization in addressing

schistosomiasis in endemic areas. They

include the following four aspects: 14

1. Preventive Chemotherapy or Selective

Treatment (Praziquantel)

a. Kill the adult worms in humans

(reservoir host) via praziquantel

based therapy

2. Vector (Snail) Control

a. Kill or replace the intermediate

hosts via biological control (e.g.

competitor snails and snail-eating

fish), chemical control

(molluscicides), and

environmental management

3. Environmental sanitation, IEC, and BCC

a. Prevent the snails from getting

infected, hence preventing

contamination of the water by

infected individuals or animals

using IEC, proper sanitation, and

behavior change

4. Safe water supplies, IEC, and PPE

a. Stop humans and animals from

getting infected by preventing

contact with water containing

infected snails or cercariae

(achieved through IEC and potable

or safe water supply)

This study examines the compliance and

implementation of the above four elements in

the province of Bohol. It also provides

empirical evidence for successful control and

13

elimination of schistosomiasis if such a multi-

component integrated approach is followed.

Lastly, it shows that a province like Bohol,

given the proper support and adequate

intersectoral cooperation at the local levels,

can competently fulfill its capacity in

effectively mobilizing local citizens into

timely action, creating a potent system that

can respond to a serious public health threat.

METHODS

Design Overview

The descriptive research involves extensive

literature reviews of the disease history,

epidemiology, and efforts for control and

elimination for schistosomiasis in Bohol.

Additionally, comparable studies of disease

control in other endemic regions of the world

have been referenced. The scope of the case

study is to demonstrate how Bohol has been

able to address the problem of schistosomiasis

and put into practice technical

recommendations from DOH, which

collaborates with WHO, to combat this

neglected tropical disease. Among such

recommendations include preventive

chemotherapy, environmental sanitation,

vector surveillance and control, and behavior

change communication.5 The study assessed

the compliance as well as effectiveness of

service delivery and program implementation

at the local level (i.e. municipalities of

Talibon and Trinidad). It therefore not only

illustrates Bohol’s recent success in reducing

prevalence rates for schistosomiasis, but also

validates the efficacy of specific public health

measures and interventions for the disease.

The analytical research component involves a

follow-up assessment of a recent study

conducted in 2014 by Belizario, et al.,

Assessment of schistosomiasis endemic areas

through parasitological and serological

techniques, which included samples from

Talibon and Trinidad. Using a select sample

from this previous study, we conducted a

qualitative analysis of schistosomiasis in the

two endemic municipalities of Bohol using

the methodology of a nested case-control

study design. Collecting household data and

surveys enabled us to evaluate the

contributing factors to Schistosoma

japonicum infections at the individual level.

We determined and measured ‘exposure’ by

designing questionnaires specific for each

type of intervention. We also tried to

corroborate our findings with available public

records and surveillance data.

14

As we will describe in the Data section, the

total sample size for this study is n = 65

(cases) + 250 (controls) = 315. We used the

samples from Belizario’s report to ‘recruit’

our cases for the ‘disease’ group (n=65),

which have been classified based on a

positive test result for ELISA (Enzyme

Linked Immunosorbent Assay) Antibody or

ELISA Antigen, serological tests for

schistosomiasis that detect previous or active

infections. The controls were then selected

from a randomized sample of individuals

from the same cohort who did not develop the

disease based on their ELISA Ab/Ag test

results. The referenced study had a total

sample size of n=414 from Talibon and

Trinidad. Ideally, all 414 subjects would be

surveyed at the end of the study; however,

realistic considerations are expected to reduce

that number. In the end, a total of 315 school

children were interviewed, of which 65 tested

positive for ELISA Ab/Ag. As such, a case

(i.e. ‘Disease Status’) was defined as any

individual who tested positive for ELISA

Ab/Ag through Belizario’s study, and each

was thus classified as a ‘residual infection’ of

schistosomiasis. Using a ‘survivor sampling’

approach, the controls consisted of

individuals from the same source population

who did not have the outcome of interest, in

this case, those who tested negative for

ELISA Ab/Ag in Belizario’s study. From the

315 total collected surveys, 250 had tested

negative for ELISA Ab/Ag.

Data: Context, Population, and Sampling The geographic area of interest includes the

two municipalities of Talibon and Trinidad in

the province of Bohol, Philippines. Along

with the comprehensive schistosomiasis case

ELISA Ab (+) [Prevalent cases of schistosomiasis]

n = 65

EXPOSED

NOT EXPOSED

Negative for schistosomiasis

n = 250

EXPOSED

NOT EXPOSED

15

study report documented in this region, the

research investigation utilized data samples

from Belizario’s study in 2014, Assessment of

schistosomiasis endemic areas through

parasitological and serological techniques

(Belizario, et al., 2015). At the time, study

participants were public elementary school

children ages 9-17 years old from two

selected village or barangay schools from

each municipality. The recruited students had

not received any treatment of praziquantel

within the last six months of the study period

in March 2014. According to the National

Schistosomiasis Control and Elimination

Program, “among difference age groups,

children ages 5-15 to have the highest

intensity of infection.”14 The sample

therefore expected to capture what evidently

seems to be the most vulnerable group of the

population, increasing its external validity and

reliability. This follow-up study occurs

approximately 1.5 years after Belizario’s

study. Thus, the study participants’ ages

range from 10-18 years old (with a mean of

13 years).

The study examined schistosomiasis-related

public health interventions in Bohol as factors

that helped prevent Schistosoma japonicum

infections. As stated earlier, infected

individuals (ELISA Ab/Ag positive) were

selected from a previous study conducted in

2014. A total sample size of n=315 was used,

and all were given questionnaires to assess

their knowledge and use of existing public

health interventions (e.g. MDA, access to

potable water, environmental sanitation, etc.)

in their localities.

Preliminary Data Collected:

Group Sample size (n)

ELISA Ab/Ag (+) 65

Other samples (-) 250

Total: 315

Dependent Variable

The outcome or dependent variable is the risk

for Schistosoma japonicum infections. We

defined ‘risk’ by using the cases that tested

positive via serological tests. While ELISA

antibody is a serological test that cannot

distinguish between both old and active

infections, ELISA antigen is able to detect

active infections within the past two years.

As such, they are considered categorical

variables, either testing positive for ELISA

Ab/Ag or not (i.e. disease risk). For study

purposes, all samples that tested positive for

ELISA Ab or ELISA Ag have been classified

as ‘residual infections’ of schistosomiasis.

16

Key Independent Variables

The key independent variables are a number

of public health intervention programs that

include: knowledge of MDA (praziquantel),

access to safe drinking water, sanitation

infrastructure, hand hygiene practices,

exposure to potential animal vectors,

exposure to potential snail sites, and exposure

to disease awareness, advocacy or health

education (e.g. BCC, IEC). We measured the

‘exposure’ to each of these interventions

through surveys and questionnaires designed

to assess the knowledge, attitudes, and

practices (KAP) of the entire population

sample.

Basic Conceptual Framework

H0 = There is no association between S.

japonicum infections and the ‘risk factor’.

§ OR = 1 would indicate that the

estimated disease risk is the same

for the exposed and unexposed.

HA = There is an association between S.

japonicum infections and the ‘risk factor’.

These factors reduce the risk or protect

against S. japonicum infections.

§ OR < 1 would indicate that the

exposure protects against

occurrence of disease (or reduces

the disease risk)

Estimation Approach & Data Analysis A major assumption in this study is that the

public health interventions in place yield a

100% success rate for eliminating the disease.

In other words, given full compliance to

DOH’s integrated approach, there should be

no remaining infections in the province.

Thus, we can treat each intervention as a

potential risk factor if an individual has failed

to fully comply or the lack thereof. Utilizing

a nested case-control study design, we

conducted a qualitative analysis of

knowledge, attitudes, and practices related the

existing public health interventions and

determine associations with risks of getting

infected with schistosomiasis. Using STATA

13, we then calculated the odds-ratio and

MDA  

Access  to  safe  water  

Sanitation  

Other  Interventions  

17

statistical significance for each variable,

which allows us to evaluate how a specific

public health intervention program affects the

risks for Schistosoma japonicum infections.

Lastly, we formulated a logistic regression

model to further explore possible interactions

between variables and draw out relationships

and their confounding effects on one another.

Procedures

Questionnaire

The survey questions were designed in

consultation with WHO and DOH,

particularly inputs from scientific experts in

fields of epidemiology, environmental

sanitation, water safety, and agriculture. It

was important to ensure that the questions are

clear and concise, as well as appropriate to the

age level of understanding of the subjects.

The main objective of the questions is to

determine exposure to a specific intervention

related to schistosomiasis. The complete list

of questions used in this study is found in the

Annex 4 (Appendix). The questions were

written in English, which is considered a

second language in the country. The

country’s official language, Tagalog, is also

widely used. Thus, the primary investigator,

a fluent Tagalog speaker, did not have any

problem communicating with local residents.

Nevertheless, for reliability purposes, the

survey questions were translated into the main

dialect, Bisaya. The questions were then

uploaded digitally using the mHealth (mobile

health) platform MAGPI. Data collectors

were only able to use a smartphone or a tablet

with the MAGPI app installed. Utilizing a

digital platform for data collection enabled us

to expedite and consolidate the process,

making data management more efficient, and

reducing human error (e.g. record, systematic

errors, etc.).

Human Subject

Since this study is considered a follow-up

from Belizario’s 2014 study, consent forms

have already been collected, which made it

easier to obtain support and full cooperation

from participants through their respective

schools. Belizario and his research team were

also directly contacted to secure their

officially signed endorsement, which linked

the two studies together. Furthermore, it is a

project endorsed by the national DOH office

and is considered a part of their M&E routine

activities, circumventing the need for an

ethics review. Lastly, the study was purely

qualitative in nature, and no additional

specimen of any kind was collected for

testing. Specific protocols as outlined by

18

DOH and WHO were followed and an

updated protection of privacy was drafted.

Endorsement of LGUs

Another important, yet often overlooked,

aspect of conducting this type of study is

ensuring that all stakeholders involved are not

only aware of the full scope of the project, but

also that their support is properly solicited. A

successful study necessitated open lines of

communication with all corresponding DOH

offices (national, regional, and provincial

levels), LGU officials (municipal mayor,

sanitation inspector, municipal health officers,

and rural health units), and the Department of

Education (school principals, teachers, parent

representatives, and departmental nurse

representative). Prior to the start of data

collection, all personnel were notified of the

national DOH endorsement and upon arrival

in Talibon, an integrative stakeholder meeting

was conducted at the local RHU to introduce

the project, coordinate technical details,

acquire additional human-resource assistance

on the ground during data collection, and

address any other concerns.

Training of NDP Nurses

The study recruited data collectors through

DOH’s Nurse Deployment Program. The

program employs locally based nurses in

Talibon and Trinidad. For this study, 10

nurses were recruited from Talibon and an

additional 8 from Trinidad. All nurses were

trained in using the MAGPI app, and the pre-

tests for the surveys were conducted with

each other. Each question was carefully

reviewed during the training, and

transcription into the local Bisayan dialect

was also performed. The data collectors were

then instructed regarding specific research

protocols such as the participants’ rights to

opt-out and how to maintain confidentiality.

School Site Visits & Data Collection

The main school sites were composed of 4

different high schools in 4 endemic barangays

(2 from each municipality), and a few other

students were tracked down in two other

elementary schools. A full day was allotted

for each school, and data collection was

coordinated through the Department of

Education nurse representative. Surveys were

conducted in a classroom setting and each

NDP nurse randomly received a unique code

ID number for the student being interviewed,

which corresponds with their undisclosed

ELISA Ab/Ag test result and allows the

primary investigator to determine whether the

subject was a case or a control. The answers

were then uploaded at the end of the day at

the RHU where Wi-Fi or Internet connection

19

was available. This provided the primary

investigator to review the data, detect errors

or discrepancies, and make any necessary

corrections or acquire additional information

from the data collector the following working

day. Data collection required 5 full working

days, where a total of 315 questionnaires were

successfully uploaded onto MAGPI.

RESULTS

Table 1 below provides the descriptive

statistics for data collected in Bohol. Among

the total of 315 study participants, 49.8%

(157) were males, while 50.2% (158) were

females. Relevant demographic data was also

gathered. The highest education level of

parents for the majority of the participants,

45.4% (143), is high school. As expected,

54% (170) could not provide information

regarding their families’ annual household

income.

For schistosomiasis-related questions, it is

important to note that the timeline of exposure

to these ‘risk factors’ must occur prior to

2014, or before Belizario’s study, since we

want to measure disease risk as detected by

the serological tests in that study. Beginning

with MDA, the majority or 44.1% (139) of

the participants recall having taken

praziquantel at least 5 times. Overall, their

knowledge of MDA seems to be very high.

85.7% (270) know the purpose of

praziquantel and 95.2% (300) believe in the

drug’s effectiveness. Significantly, 35.9%

(113) of the students have experienced an

adverse event immediately following

praziquantel intake; the largest value being

headache (18.1%), followed by dizziness

(13.3%), and thirdly, abdominal pain (8.9%).

With regards to access to safe drinking water,

only approximately 32.1% (101) of the

participants could be considered as having

had access to potable water. Conversely, a

notably high number, 93.7% (295) of the

students have had access to a functional toilet

or latrine (water-sealed) at home.

Furthermore, 84.4% (266) would wash their

hands after using the toilet at home, of which

77.1% (243) use soap. In school, this practice

seems to decrease as only 73.3% (231) would

wash their hands, of which 48.3% (152) use

soap. There are also a high number of

participants who have been exposed to

potential animal vectors, 80.6% (254) having

kept domesticated animals or pets (dogs, cats,

or rodents) at home, while 70.5% (222)

having had direct contact with bovine or farm

animals (pigs, water buffaloes, cows, etc.).

20

Table 1: Descriptive statistics of variables

VARIABLE STATISTICS Gender n = 315 Proportion Cases Controls

Male

157 49.8% 25.5% n = 40

74.5% n = 117

Female

158 50.2% 15.8% n = 25

84.2% n = 133

Highest education level of parents n = 315 Proportion Elementary 97 30.8%

High School 143 45.4% College 45 14.3%

Post-graduate or Advance degree 0 0% Unknown

30 9.5%

Annual household income n = 315 Proportion <5,000 pesos 38 12.1%

5,000-15,000 pesos 15,000-25,000 pesos 25,000-50,000 pesos

>50,000 pesos Unknown

31 24 26 26 170

9.8% 7.6% 8.3% 8.3% 54%

MDA participation (praziquantel intake) n = 315 Proportion Never 1 0.3% 1 time 19 6.0%

2 times 3 times 4 times

>5 times Unsure

51 47 48 139 10

16.2% 14.9% 15.2% 44.1% 3.2%

Knowledge of praziquantel n = 315 Yes No Unsure Purpose of praziquantel 270 85.7% 11.7% 2.5%

Belief in praziquantel’s effectiveness

300

95.2%

2.2%

2.5%

Experience with adverse events

Dizziness Headache

Malaise Drowsiness

Fatigue

113 42 57 5 3 8

35.9% 13.3% 18.1% 1.6% 1.0% 2.5%

62.9% 86.7% 81.9% 98.4% 99.0% 97.5%

1.3%

21

Abdominal pain Diarrhea Vomiting

Nausea Bodily pain

Fever Numbness

Others not listed

Future participation in MDA

28 6 13 9 0 3 0 2

307

8.9% 1.9% 4.1% 2.9% 0% 1.0% 0% 0.6% 97.5%

91.1% 98.1% 95.9% 97.1% 100% 99.0% 100% 99.4% 2.5%

---

Access to safe drinking water n = 315 Proportion Mineral water (e.g. bottled or purchased) 89 28.3%

Boiled Tap

Pump or borehole Ground well water

Rainwater Water from stream, creek, or river

4 8 17 196 1 0

1.3 2.5% 5.4% 62.2% 0.3% 0%

Sanitation infrastructure n = 315 Yes No Functional toilet or latrine (water sealed) used at home. If not, list other methods:

295 93.7%

6.3%

Communal or shared Dug pit in the ground

Open space in the backyard Closest stream, creek, or river

Anywhere convenient

Other methods of feces disposal: Trash collection by LGUs

Burned in the backyard Buried in the ground

Thrown in nearby stream, creek, or river Thrown anywhere convenient

Others not listed above Not applicable

6 3 7 0 4 0 0 87 7 12 62 165

1.9% 1.0% 2.2% 0% 1.3% 0% 0% 27.6% 2.2% 3.8% 19.7% 52.4%

Hand hygiene practices n = 315 Yes No At home:

After toilet use With soap

In school: After toilet use

With soap

266 243

231 152

84.4% 77.1% 73.3% 48.3%

15.6% 7.6% 26.7% 25.1%

22

Exposure to potential animal vectors n = 315 Yes No N/A

Household pets (dogs, cats, or rodents)

Farm animals (pigs, water buffaloes, cows, or other bovines)

254

222

80.6% 70.5%

14.9% 19.4%

4.4% 10.1%

Exposure to potential snail sites n = 315 Yes No Freshwater aquatic environments such as ponds, creeks, streams, or rivers, as well as artificial waterways:

Laundry practices Bathing practices

Water collection practices

130 225 19

41.3% 71.4% 6%

58.7% 28.6% 94%

Exposure to disease awareness, advocacy campaigns, and health education

n = 315

Yes

No

Community awareness or campaigns School-related activities

177 223

56.2% 70.9%

43.8% 17.8%

Social media or platforms: TV

Radio Magazine

Newspaper Internet

Others not listed

122 24 5 8 3

134

38.7% 7.6% 1.6% 2.5% 1% 42.5%

61.3% 92.4% 98.4% 97.5% 99% 57.5%

For those who have had exposure to

potential snail sites (which includes

freshwater aquatic environments and

artificial waterways) prior to Belizario’s

2014 assessment, 41.3% (130) of the

participants reported having been involved

in laundry practices, an even much higher

number at 71.4% (225) with bathing

practices, but a relatively low number at 6%

(19) involving water collection practices.

Lastly, among all study participants, 56.2%

(177) have been exposed to community

awareness or health campaigns regarding

schistosomiasis; 70.9% (223) have

participated in school-related activities that

promoted health education for the disease;

and among all social media or platforms,

38.7% (122) remember having seen or

learned about schistosomiasis awareness on

television, the highest among all other listed

choices.

23

Table 2 below shows the odds ratio for each

risk factor and their corresponding statistical

significance. In theory, an OR that is less

than 1 and is statistically significant (i.e. at

the 95% level), means that exposure to the

risk factor protects against the occurrence of

the disease (i.e. schistosomiasis) or reduces

disease risk. One of the major assumptions

involved in such statistical analyses is that

the test assumes independent data. In other

words, there is no association between or

among the data sets being collected and

tested. Another assumption is that the data

set has a normal distribution. For the

purpose of this study, we have set the alpha

at 0.05 to determine statistical significance.

The sample size is n=315, which we

estimated to be sufficient (i.e. power and

effect size) in carrying out the desired

statistical tests.

Solely interpreting the odds ratio in Table 2

indicates that access to potable water, hand

hygiene practices, and exposure to social

media or platforms (TV and newspaper)

seem to have a protective effect for the

disease, or reduce the disease risk. On the

contrary, the estimated disease risk for those

who have been exposed to potential animal

vectors and snail sites (laundry and bathing

practices), seem to be greater for the

exposed group. Sanitation infrastructure,

community awareness, and school-related

activities seem to have a neutral effect.

However, when we consider statistical

significance, only exposure to television (i.e.

promoting advocacy or health education

regarding schistosomiasis), is statistically

significant, with a p-value of 0.011 and CI

of 0.23-0.87 (i.e. excludes the value 1.0, and

allows us to reject the null hypothesis).

In order to account for interactions among

the variables, we ran a logistical regression

model, as shown in Table 3 below. The

results now indicate that 1) sanitation

infrastructure, 2) exposure to potential

animal vectors (specifically bovine or farm

animals), and 3) exposure to school-related

activities that promote health education, are

all statistically significant. As all other

independent variables are held constant,

their respective coefficient values suggest

that sanitation infrastructure (-2.01) and

participation in school-related activities or

health education (-0.781) could significantly

be considered protective factors for the

disease, while exposure to potential bovine

or farm animal hosts (2.27) likely increases

the risk for the disease.

24

Table 2: Odds ratio of potential risk factors for S. japonicum infections among school-age children in Bohol RISK FACTORS p-value Odds Ratio CI (Odds; 95%) Knowledge of MDA

Purpose of praziquantel Belief in praziquantel’s effectiveness

Experience with adverse events

Access to safe drinking water Mineral, boiled, and tap vs.

Borehole and Ground water well

Sanitation infrastructure Functional toilet or latrine (water sealed)

Hand hygiene practices

At home; after toilet use At home; with soap

In school; after toilet use In school; with soap

Exposure to potential animal vectors

Household pets (dogs, cats, rodents) Farm animals (pigs, water buffaloes, cows)

Exposure to potential snail sites (i.e. aquatic environment such as ponds, creeks, streams, or rivers)

Laundry practices Bathing practices

Water collection practices

0.776 1.00† 0.827

0.357

1.00†

0.468 1.00†

0.142 0.414

0.789 0.591

0.092 0.428 0.774†

0.895 1.59 1.07 0.765 1.04 0.767 0.960 0.645 0.753 1.11 1.22 1.60 1.29 0.708

0.40 - 2.16 0.19 - 74.5 0.57 - 1.95 0.42 - 1.42 0.32 - 4.44 0.36 - 1.73 0.32 - 3.45 0.35 - 1.23 0.36 - 1.60 0.49 - 2.78 0.57 - 2.81 0.89 - 2.87 0.67 - 2.58 0.13 - 2.59

Exposure to disease awareness, advocacy campaigns, and health education

Community awareness School-related activities

TV Radio

Magazine Newspaper

Internet Others not listed

0.883 0.672 0.011* 1.00†

1.00†

1.00† 0.508†

0.095

1.04 1.16 0.451 0.989 0.940 0.530 1.90 1.47

0.58 - 1.87 0.53 - 2.43 0.23 - 0.87 0.28 - 2.91 0.02 - 9.74 0.01 - 4.27 0.03 - 36.9 0.90 - 2.36

CI indicates Confidence Interval; †Fisher’s exact test; *Significant of p<0.05

25

Table 3: Logistic regression model for ‘Disease Status’ among school-age children in Bohol Disease Status (Outcome Var.) Coef. Std.

Err. z P > z 95% CI

Gender: Female Knowledge of MDA

Purpose of praziquantel Belief in praziquantel

Adverse events

Access to safe drinking water

Sanitation infrastructure Functional toilet or latrine

Hand hygiene practices

At home; after toilet use At home; with soap

In school; after toilet use In school; with soap

Exposure to animal vectors

Household pets Farm animals

Exposure to snail sites (i.e. aquatic environments)

Laundry practices Bathing practices

Water collection practices

-0.358

1.03 0

-0.268

-1.09

-2.01

0

0.342

0 -0.413

-0.682 2.27

0.187 -0.1

-0.477

0.503 0.909 --- 0.491 0.133 0.979 --- 0.874 --- 0.495 0.712 1.09 0.566 0.619 0.925

-0.71 1.14 --- -0.55 -0.82 -2.05 --- 0.39 --- -0.83 -0.96 2.08 0.33 -0.16 -0.52

0.477 0.254 --- 0.585 0.413 0.040* --- 0.695 --- 0.405 0.338 0.037* 0.741 0.871 0.606

-1.34; 0.63 -0.75; 2.82 --- -1.23; 0.69 -3.91; -0.08 -3.93; -0.09 --- -1.37; 2.06 --- -1.38; 0.56 -2.08; 0.71 0.13; 4.42 -0.92; 1.30 -1.31; 1.11 -2.29; 1.34

Exposure to disease awareness, advocacy, and health education

Community awareness School-related activities

TV Radio

Magazine Newspaper

Internet Others not listed

-0.645 -0.781 -0.483

0

0.541

0 0

0.093

0.340 0.385 0.569 --- 1.56 --- --- 0.846

-1.89 2.03 -0.85 --- 0.35 --- --- 0.11

0.058 0.042* 0.395 --- 0.728 --- --- 0.913

-1.31; 0.02 0.03; 1.53 -1.60; 0.63 --- -2.51; 3.60 --- --- -1.57; 1.75

CI indicates Confidence Interval; *Significant of p<0.05; Log likelihood= -59.76; Number of observations= 136; LR chi2(3)= 18.79; Prob>chi2= 0.22; Pseudo R2= 0.14

26

DISCUSSION

Mass Drug Administration

MDA is a term used for community drug

distribution. In Bohol, community health

providers, BHWs, and individual volunteers

have been trained for protocols and

procedures regarding proper administration

of praziquantel.14 Currently, praziquantel is

the only medicine recommended by WHO

for treatment of all forms of schistosomiasis

in both children and adults.5 A single oral

dose of 40-mg/kg body weight is considered

adequate to provide cure rates of between

60-90% and reductions of 90-95% in the

average number of excreted eggs.14

Unfortunately, despite the significant cost

reductions that have followed patent expiry,

praziquantel remains one of the most

expensive anthelminthics on the market.5

For the time being, DOH has partnered with

WHO to procure sufficient annual supply of

the medicine. If the disease continues to

persist, it poses the question of sustainability

in acquiring this essential drug.

During the past decade, the Philippine

national government, spearheaded by the

Department of Health, released

Administrative Order No. 2007-0015, which

declared praziquantel as the standard drug of

treatment for schistosomiasis. It regulated

the administration of praziquantel at a dose

of 60-mg/kg body weight for 1 day taken in

2 divided doses at 4-6 hour interval.14

Furthermore, it has declared July as the

Annual Schistosomiasis Awareness and

MDA Month. This approach has not only

created a sense of solidarity and purpose, but

has also significantly boosted the

knowledge, especially among school-age

children regarding schistosomiasis and the

best practices for prevention.

The results of this study indicate that a high

percentage of school-age children in Bohol

possess sound knowledge of MDA, its

purpose, and consequence. The majority

also trusts in its ability to treat the disease.

In Bohol, MDA is methodically

implemented through the gathering of at-risk

school-age children (i.e. primary schools in

endemic barangays), as well as making

house visits to those who are not in school

due to absenteeism or dropouts. The

commitment and coordinated efforts from

different sectoral groups, including the

LGUs, the Department of Education, and

DOH have ensured the timely and high

coverage rates of MDA in Talibon and

Trinidad from 2009 to 2013, and again in

27

2015. Figures 4A and 4B indicate the high

percentage rates of MDA accomplishment in

the two municipalities.17,18 Talibon was able

to administer praziquantel among 76% of its

total population target during its first year of

MDA in 2009. Since then, that figure has

increased consistently in the following four

years, achieving 80%, 83%, 96%, and 97%

successively. Even with the one-year gap or

missed MDA in 2014, the MDA coverage

was highly maintained at 96%.

Figure 4A. MDA accomplishment in Talibon, Bohol (2009-2013, 2015)

Figure 4B. MDA accomplishment in Trinidad, Bohol (2009-2013, 2015)

Trinidad has virtually accomplished a

similar feat. Its first MDA year in 2009 had

a coverage rate of 84%. This increased

significantly the next four years, recording

at 89%, 98%, 99.8%, and 99.9%; and an

impressive 100% accomplishment in 2015.

Nonetheless, the successful implementation

of MDA during those six years was not

without its challenges. Yet the actions

taken, especially by the RHUs, in response

to such issues can serve as important

learning points for other endemic regions.

For example, after its first year of

implementation in 2009, there were a

decreased number of children given parental

consent for MDA. This was attributed to

several factors, including the adverse effects

experienced by children after taking

praziquantel and false rumors regarding the

drug’s negative impact on the body. Thus,

the RHUs set out to cultivate stronger

advocacy and health promotional campaigns

to increase disease awareness and the

importance of MDA. This also addressed

the rumors about the ill effects of

praziquantel and other misinformation

regarding the drug. Just as crucial to note is

that advocacy and health education were

directed through proper channels such as the

LGUs and the Department of Education.

76%   80%  83%  

96%   97%   96%  

0%  

25%  

50%  

75%  

100%  

2009   2010   2011   2012   2013   2015  

Accomplishm

ent  (%)  

84%   89%  98%   99.8%  99.9%  100%  

0%  

25%  

50%  

75%  

100%  

2009   2010   2011   2012   2013   2015  

Accomplishm

ent  (%)  

28

Conscious efforts were made to involve

LGU personnel, local leaders, and

schoolteachers in health trainings for

MDA.19, 20 Another concern that arose was

that the administering of praziquantel would

be time consuming. To tackle this issue, the

RHUs prepared the drugs in advance before

the actual day of MDA. This involved

preparing the praziquantel per anticipated

student (i.e. with body weight records

already collected to determine proper

dosage) and with divided doses for the

morning and afternoon sessions.19, 20

Finally, the challenge of high incidence of

adverse effects, especially during the first

year (2009) needed to be addressed. In the

subsequent years, a separate budget from the

regional DOH office was allotted for meals,

as school children were provided breakfast

and lunch prior to taking praziquantel. This

effectively minimized adverse events and

reactions to praziquantel. In addition,

supportive medicines were made available

and given as prescribed by a community

health professional. Health education also

played an important role in reassuring

parents and their children the markedly

reduced difference in adverse effects of

praziquantel during the first year of taking

the drug (i.e. severe cases of adverse advents

are correlated to larger egg counts in the

body), compared to the successive years of

receiving such treatment.17, 18

Vector Control The WHO states that vector and

intermediate host control “serve as an

important cross-cutting activity aimed at

enhancing the impact of preventive

chemotherapy and intensified disease

management.” 2 For the S. japonicum

species in the Philippines, the known

intermediate host is the snail Oncomelania

hupensis quadrasi. These snails inhabit

shallow muddy sediments of lentic, lotic,

freshwater systems including ponds,

streams, rivers, lakes, irrigation canals, and

heavily irrigated agricultural fields. The

primary ecological determinants of their

habitat suitability include temperature,

sunlight, water flow, and presence of

macrophytic aquatic plants.4 Studies have

found that light intensity and the number of

O. quadrasi in a given site are inversely

related. The reduced activity of snails

during the day and their avoidance of bright

light indicate the necessity of cover.7

Furthermore, high temperatures over long

periods of time have been known to limit

snail fecundity. Experimental studies have

29

suggested that direct sunlight can have lethal

effects on snails, as they tend to avoid direct

sunlight exposure and prefer shaded areas

usually provided by dense vegetation.4

In the 1990s, many of the citizens living

near or around the snail sites in Talibon and

Trinidad remained hesitant to clear the snail

sites where the native ‘gabi’ (taro) plant has

been commonly found. The very broad taro

leaves provided the ideal shade for O.

quadrasi snails. At the same time, however,

they also provided a source of food for the

local inhabitants during the dry season.

Therein lies the problem of community

cooperation, as with any public health

intervention programs.23 With the support

from LGUs and the Department of

Agriculture, the MHOs have successfully

convinced many of these landowners to

convert their lands into rice fields.

Certainly, it took considerable time, effort,

and financial resources to accomplish such

feat, and it remains to be perhaps one of the

unique aspects of the effective vector control

for schistosomiasis in Bohol. Currently, the

two municipalities conduct quarterly (i.e. 4

times a year) clearing of snail sites in the 19

known sites where O. quadrasi snails have

been found.17, 18 With funding and personal

protective equipment (PPE) provided by the

RHO, local staff from the MHO and the

Schistosomiasis Task Force Team, organize

and conduct the clearing of snail sites. Their

goal is to primarily get rid of dense

vegetation that provides the desirable shade

for snail vectors. Furthermore, several of

the snail sites have already been converted

into rice fields, many of which have proper

irrigation systems, in accordance to

regulations set forth by the National

Irrigation Administration (NIA).

In relation to the study conducted, results

have shown that 41.3% of the participants

are possibly at risk for exposure to potential

snail sites through their laundry practices,

while 71.4% are at risk due to bathing

practices. Although without statistical

significance, the ORs indicate that both

practices do seem to increase the disease

risk (Table 2). Furthermore, a one-unit

increase of exposure to other known animal

vectors such as bovine or farm animals

indicate a 2.27 increase in the log-odds of

disease risk at the significant level (Table 3).

It is therefore crucial moving forward to

maintain robust strategies for vector control,

as what they have already pioneered in

Bohol. In the past, mollusciciding was the

other option for snail vector control.24

However, in an effort to support

30

environmental health and protection, the

Philippine government has banned the use of

molluscicides in the country. Thus, the

NSCEP has been conducting snail control

via active disease surveillance and

promoting other practical solutions.

Malacological surveys, albeit limited, are

also conducted on a periodic basis and are

usually contracted out to independent

research institutions, such as that of

university-affiliated groups.17, 18

Environmental Sanitation Environmental sanitation encompasses the

control of animal movement, proper use of

toilet, access to clean and safe water supply,

and the use of footbridges when crossing

infected canals or waterways.11 The two

endemic municipalities in Bohol have

prioritized the provisions of sanitary toilets

in their communities, especially in the

endemic barangays. Currently, there is a

budget allotted so households in need may

obtain water-sealed toilets at an affordable

price (the cost is about 50 pesos each, or

equivalent to roughly US$ 1), including

instructions for installation and free cement

supply provided by the barangay units. For

families below a certain income level, the

toilets are subsidized by the LGUs. From

the total supply for toilets, about 30% are

acquired through donations. The LGUs

provide assistance with the proper

construction and installation of toilets. They

also conduct annual inventory of households

with sanitary toilets to determine their needs

and targets for the next fiscal year.17, 18

Figure 5A. Households with access to sanitary toilets in Talibon (2014-2015)

Figure 5B. Households with access to sanitary toilets in Trinidad (2014-2015)

81%  

89%  

93%  

86%  

92%  

90%  

95%  

94%  

0%   20%   40%   60%   80%  100%  

San  Agustin  

San  Carlos  

San  Jose  

San  Roque  

2015   2014  

93%  

87%  

93%  

98%  

95%  

92%  

95%  

100%  

0%   20%   40%   60%   80%  100%  

Kinan-­‐oan  

Mabuhay  Cabiguhan  

San  Vicente  

Santo  Tomas  

2015   2014  

31

Figures 5A and 5B show the 2014-2015

inventory reports of households with

sanitary toilets in the endemic barangays of

Talibon and Trinidad. In 2014, Barangay

San Agustin in Talibon had the lowest

percentage of households with sanitary

toilets at 81%. The following year, as with

the rest of the endemic barangays, this

number increased to 92%. As of 2015, the

percentage of households with sanitary

toilets ranges from 90% to 95%. Similarly,

Trinidad has shown remarkable numbers in

their indicators, as the percentage of

households with sanitary toilets in the four

endemic barangays in 2015 range from 92%

to 100%, with steady increases from the

previous year. Statistical analyses from the

study indicate that the proper use of

sanitation infrastructure significantly

contributes to the reduction of disease risk

among study participants (0.04 p-value), and

that a one-unit increase in the use of

functional, water-sealed toilets or latrines

results in a 2.01 decrease in the log-odds of

disease risk (Table 3).

Moreover, the NSCEP constantly

encourages alternative and practical

solutions, especially for a neglected tropical

disease like schistosomiasis. This includes

building safety measures such as bridges,

over bodies of water identified to have the

snail disease carrier.11 These measures are

clearly visible in Talibon and Trinidad.

Working with the RHUs, the barangay

LGUs recognize the importance of investing

in these types of complementary public

health interventions. As with other health

programs, education and advocacy play

important roles in securing the support of

LGUs and their willingness to take action.

It also increases the demand from the public

to prioritize these programs in their

communities. By taking action, it shows not

only their strong commitment in fighting the

disease, but also their active participation in

community development.

Safe Water Supplies

According to a recent report by the United

Nations, over 900 million people lack access

to safe drinking water, while 2.5 billion live

without proper sanitation.3 The WHO has

stated that “until this situation improves,

many neglected tropical diseases and other

communicable diseases will not be

eliminated, and certainly not eradicated.” 3

This perhaps is one of the most critical

roadblocks in Bohol’s path to becoming a

100% schistosomiasis-free province.

Among the four major approaches

32

recommended by DOH for disease control

and elimination, access to safe water supply

is evidently the one that needs the most

attention. Schistosomiasis is mainly

transmitted through unsanitary practices of

inhabitants in communities and their lack of

access to safe and potable water.11 For

example, many families are left no choice

but to collect water in natural reservoirs

nearest to them. The collected survey data

indicate that although a large portion of

children may have access to safe drinking

water via consumption of mineral water

bought in stores, many still tend to collect

water in streams or rivers and is used for

other household needs, such as laundry,

bathing, and cleaning. According to the

LGUs, one challenge for them is the lack of

infrastructure for water supplies as well as

incentive for water companies to build them,

limiting the amount of safe water supplies

that can reach the remote areas of the

endemic barangays. In this regard,

intersectoral discourse must be initiated and

stakeholders, both public and private, must

be engaged to find a suitable solution.

Figures 6A and 6B show the recent survey

reports of households with access to safe

water supply (at all source levels) in the

endemic barangays of the two municipalities

in the previous two years. As expected,

Talibon, being a 1st income class

community, shows the higher percentages of

households compared to Trinidad. Although

the majority has at least a 90% of total

households with access, one of its endemic

barangays, San Roque, only has 65% of

households with access. Conversely,

Trinidad’s endemic barangays have

relatively low percentages, all of which

coming below 50% (22%, 30%, 34%, and

49%). These values are corroborated by the

study results, wherein only 32.1% of the

participants reported having access to

potable water, while 67.9% are considered

without access. With further studies, such

findings could imply an indirect relationship

between the participants’ access to water

and their exposure to potential snail sites.

Figure 6A. Households with access to safe water supply in Talibon (2014; *2015 data currently unavailable)

92%  

90%  

95%  

65%  

0%   20%   40%   60%   80%  100%  

San  Agustin  

San  Carlos  

San  Jose  

San  Roque  

2014  

33

Figure 6B. Households with access to safe water supply in Trinidad’s endemic barangays (2014-2015)

Advocacy and Health Education Perhaps the most underrated, yet one of the

most effective tools of public health

intervention is through advocacy and health

education.24 This involves teaching citizens

of the community about best hygiene

practices, such as hand washing, proper

sanitation, and other practical preventive

measures against the disease. Furthermore,

resources from the government and other

implementing partners, such as the WHO,

will be insufficient if the people themselves

along with their local leaders do not feel

ownership and recognition of the program.

Such is attained through intensive advocacy

and social mobilization to empower and

ensure that the people possess the right

knowledge and information regarding the

disease. A fundamental and critical aspect

of Talibon and Trinidad’s success against

schistosomiasis is their understanding of the

disease, particularly the agent S.

japonicum’s life cycle. The MHOs

recognize that interrupting transmission

requires an understanding of the parasitic

life cycle.19, 20 It is one of their main

winning ingredients in their recipe for

disease control and elimination. As a result,

they continue to support and develop a

multi-component integrated approach to

fight the disease. This includes all health

intervention activities as discussed: MDA,

vector control, environmental sanitation,

safe water supplies, and health advocacy and

education. In both RHUs, health providers

regularly (e.g. NDP nurses) circulate around

endemic barangays and public schools to

teach both adults and children about

schistosomiasis, including its prevention and

treatment, emphasizing the current public

health programs being implemented. This

encourages a participatory and collaborative

environment, and strengthens the overall

structure and effectiveness of the program.

Remarkably, the results indicate that a one-

unit increase in exposure to school-related

activities (i.e. health education for

schistosomiasis) decreases the log-odds of

disease risk by 0.781 at a statistically

significant level (0.042 p-value).

55%  

22%  

41%  

38%  

30%  

22%  

49%  

34%  

0%   20%   40%   60%   80%  100%  

Kinan-­‐oan  

Mabuhay  Cabiguhan  

San  Vicente  

Santo  Tomas  

2015   2014  

34

Other Determinants

‘Schistosomiasis Task Force’

The DOH Region VII office has established

a ‘Schistosomiasis Task Force’ to regularly

conduct meetings, report, and assess the

overall situation of the disease in each

endemic barangay. A team for each

endemic barangay is consisted of 50

individuals representing LGU officials,

DOH representatives, and other local civil

servants.17, 18 Currently, they conduct

quarterly meetings to evaluate the status and

progress of the four major public health

programs in their respective barangays.

They are also in charge of scheduling

regular clearings of snail sites in their areas,

coordinating plans, and gathering

volunteers. The task force is composed of

the following individuals:

1 Midwife

1 Nurse

10 Barangay Health Workers

10 Barangay Officials

16 Barangay Workers

1 Barangay Nutrition Scholar (BHW)

3 Utility Personnel

3 Department of Education representatives

5 from Sectorial Working Group

- Mothers’ Organization (1)

- Pastoral (President & Secretary) (2)

- Farmers and Fishermen Organization

Representative (1)

- Women’s Association

Representative (1)

Financial Resources and Funding

The availability of budget for any public

health program is a major factor determining

its proper and timely implementation. Many

public health interventions, such as

environmental sanitation, aim to address

multiple diseases by preventing transmission

and infection. The funding provided by the

NSCEP for schistosomiasis funnels down to

the DOH Regional Office and then to the

PHO, which determines the allotment of

budgets for its municipalities based on needs

for the fiscal year. MHOs may receive

funding for specific types of intervention.

For example, the meal budget for MDA is

provided by DOH, while the LGUs may

choose to supplement an activity at their

own expense. The LGUs at the barangay

levels also receive national funding from the

Internal Revenue Allotment (IRA), and may

use part of that budget to support a public

health program. For instance, in a fiscal

year, a barangay may receive roughly 3

million pesos from IRA, of which

approximately 20% of is allocated as

Development Fund, while another 9% is

35

used for Maintenance Operation and Other

Expenses.17, 18 The endemic barangays in

Talibon and Trinidad utilize this specific

fund to subsidize sanitary toilets for families

with qualified needs. With advocacy from

the RHUs, the LGUs have prioritized and

allocated a portion of their annual budget to

support complementary public health

interventions. Through health education,

they are also aware of the benefits of

sanitary toilet provisions, which not only

help prevent disease transmission, but also

improve the overall health and wellbeing of

their communities.

Comprehensive planning and coordination

among different sectors can help detect

sources for funding and extend a program’s

lifespan. This not only saves money, but

also saves time, and promotes accountability

for sectoral groups responsible and

committed to such projects. Since the

majority of financial resources come from

the central offices, they must be more

involved and committed to adequate budget

acquisition and appropriate fund utilization.

The MHOs and LGUs are limited to what

they can accomplish in their programs by

what they have been provided and

administered to do so. Thus, the central and

local offices must work in unison to ensure

positive results from public health projects

and maximize budget efficiency.

Local Incentivization

Talibon and Trinidad have also developed

the value of incentivizing health outcomes

beyond the individual and household levels.

The Annual Foundation Day dispenses

rewards and recognition to barangays that

have attained positive health outcomes

based on specific health indicators such as

sanitation infrastructure and access to safe

water.19, 20 The annual event takes place in

February or March, and the evaluation is

conducted by officials from the LGUs and

MHOs, assessing which barangays have

achieved the highest marks from the

previous year. This creates a sense of

healthy competition among the barangays,

which motivates them to work together in

finding ways to continually improve the

health conditions in their communities.

Barangay Spot Maps

Another component of Talibon and

Trinidad’s program is the utilization of

‘barangay spot maps’. The maps show

select health indicators such as households

with unmet needs. These may vary slightly

by barangay, but generally, they include

income level, indicators for maternal and

36

child health, environmental sanitation

indicators such as sanitary toilets, access to

safe drinking water, and even house

construction materials. 17, 18 Every

household in the barangay is accounted for,

with the BHWs responsible for collecting

the data and updating them on an annual

basis. This is extremely useful for the

disease control and elimination efforts of

schistosomiasis, as they provide the most

reliable information to LGUs and RHUs that

determine unmet needs and other ways to

improve specific elements of a given public

health intervention.

CONCLUSION

Design Critique & Limitations Considering the timeline of two and a half-

months (September-November), the project

benefitted from having a nested case-control

study design, as they are generally simple to

organize. By retrospectively comparing two

groups within a nested sample, we were able

to identify predictors of an outcome (i.e.

how public health interventions affect the

risk for S. japonicum infections). To assess

the influence of predictors on the outcome,

we then calculated the odds ratio of disease

risk based on exposure. Nevertheless, as

with any other studies, a case-control design

has its limitations. This includes sample bias

(i.e. where we obtained our cases and

controls), as well as observation and recall

biases (e.g. from the participant, the

investigator, and/or data collectors). Specific

characteristics of the participants selected

also determine the bounds for which we can

make generalizations for the larger

population groups (i.e. external validity).

Lastly, this type of study design allows us to

look at only one outcome, since we recruited

based on disease status. To mitigate some of

these weaknesses, we maximized the

number of our control group (n=250), and

recruited our controls from the same pool

(i.e. age range, residential geography,

school, etc.) that was tested for ELISA

Ab/Ag. In theory, this should yield similar

chances of risks for the disease and chances

of exposure to any given intervention.

Careful consideration of other confounding

factors should therefore result in more

robust and reliable conclusions.

Current Needs & Future Outlook

Most of the routine data collection for this

case study took place in the last quarter of

2015. Although the areas of concern are

37

diverse, immediate attention is needed to

address issues related to both the short and

long-term successes of public health

programs currently in place. Along with the

quantitative results, the recommended

course of action is to carefully examine the

following items in order to support and

further enhance the schistosomiasis control

and elimination program in Bohol.

¨ Provision of safe water supplies: As

indicated, recent data suggest that

there is a significant need for

families in the endemic areas to have

better access not only to potable

water, but also for other daily

household use.

¨ Agricultural sector: Considerations

of treating animals (i.e. bovine or

farm animals) with praziquantel.

Although they conduct regular

deworming and treatment of farm

animals for other diseases, there is

currently no available treatment for

schistosomiasis in animals. Other

alternatives, such as the use of

machinery should also be explored to

address the risks posed by disease

transmission in animals.24, 25

¨ Malacological trainings: There

should be a concerted effort to

increase and develop the surveillance

and surveying of the snail vectors.24

¨ Health Education & Awareness: As

reinforced by the study, these

components play a vital role and

should not only be sustained, but

also continually improved upon.

Recommendations for Future Study & Final Remarks

The study could be greatly enhanced in the

future by utilizing GIS technology and

techniques that could provide more definite

geographical clues and epidemiological

support, especially in evaluating residual

infections that still persist in the region.

Surveys could also be applied to a larger

population sample, or other at-risk

subgroups of the community, which will

likely increase the study’s external validity

and reliability.

Moving forward, both MHOs in Talibon and

Trinidad believe that with the current

progress of their strategies to tackling

schistosomiasis, the road to elimination is

not far in sight. Timely MDA, proper

environmental sanitation, added focus on

animal transmission, consistent modification

of endemic sites, advocacy and health

education, and diligent surveillance that

38

involves active case finding and treatment,

all contribute to their success. Coordination

with the LGUs, particularly at the barangay

levels, must be maintained and amplified as

necessary. Those involved must realize that

ending the neglect will never be successful

without the full cooperation of the local

communities at risk. The experience of

Bohol and its two endemic municipalities

can serve as useful blueprints for other areas

in the country that continue to suffer from

the heavy burden of this disease. Each area

may bring unique challenges that are

specific to the capacity of the current system

in place. Nonetheless, with strong

commitment and by cultivating a synergistic

intersectoral collaboration among all

stakeholders involved, as Bohol has aptly

demonstrated, the foundation and path to

disease elimination can be decisively laid.

39

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(0910). Bilharzia in the Philippines: Past, present, and future [Bilharzia; Control;

Philippines; Schistosoma japonicum; Schistosomiasis. 10.1016/j.ijid.2013.09.011 [doi].

2World Health Organization. (2010). Working to overcome the global impact of neglected

tropical diseases. (First WHO report on neglected tropical diseases No. 1). Geneva,

Switzerland: WHO Press.

3World Health Organization. (2012). Accelerating work to overcome the global impact of

neglected tropical diseases: A roadmap for implementation. (Executive Summary).

Geneva, Switzerland: WHO Press.

4Akullian, N. A. (2007). Spatial patterns of schistosomiasis: A watershed approach to measuring

S. japonicum environmental risk and human and animal disease outcomes. Providence:

Brown University.

5World Health Organization. (2013). Schistosomiasis: Progress Report 2001-2011 and Strategic

Plan 2012-2020. France: World Health Organization.

6World Health Organization. (2015). Schistosomiasis: A major public health problem. Retrieved

from http://www.who.int/schistosomiasis/en/

7Blas, B. L. (Ed.). (1988). Surveys, studies, and control work on schistosoma japonicum infection

in the Philippines. Manila: Schistosomiasis Control Service, DOH.

8Blas, B. L., Velasco, P. F., Alialy, O. B., Basas, J. C., & Bautista, E. S. (1990). Epidemiology

and control of schistosomiasis in the Philippines. (Review). Manila, Philippines:

Schistosomiasis Control Service, DOH.

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9Blas, B. L., & Dazo, B. C. (1968). Schistosomiasis survey and preliminary control work in the

province of Bohol. The Journal of the Philippine Medical Association, 44(2), 80-87.

10Palasi, W. A. (2015). Schistosomiasis in the Philippines. (Presentation). Manila: Department of

Health: Disease Prevention and Control Bureau.

11Department of Health, P. (2014). Neglected tropical diseases in the Philippines (1st ed.). Sta.

Cruz, Manila: National Disease Prevention and Control Bureau, DOH.

12Blas, B. L., Bautista, E. S., & Lipayon, I. L. (Eds.). (1990). An atlas on the endemicity of

Schistosomiasis japonica in the Philippines (2nd ed.). Manila: Schistosomiasis Control

Service, Department of Health.

13A national baseline prevalence survey of schistosomiasis in the Philippines using stratified

two-step systematic cluster sampling design (2012). Retrieved from

http://dx.doi.org/10.1155/2012/936128

14National Schistosomiasis Control and Elimination Program (Ed.). (2012). Schistosomiasis:

Clinical practice guidelines for the diagnosis, treatment, and prevention of Schistosoma

japonicum infections in the Philippines: 2012 update. Manila: Department of Health.

15National Schistosomiasis Control and Elimination Program. (2015). Sentinel surveillance

report 2009-2014. (Surveillance). Manila: Department of Health: NSCEP.

16Belizario, V. J., Gabanuda, R. R., Amarillo, M. L., & de Veyra, C. (2015). Assessment of

schistosomiasis endemic areas through parasitological and serological techniques. (Final

Report). Manila: University of the Philippines, Manila.

17Talibon Municipal Health Office. (2015). Routine data collection in Talibon's rural health unit.

(Health Reports). Talibon, Bohol: Talibon RHU.

41

18Trinidad Municipal Health Office. (2015). Routine data collection in Trinidad's rural health

unit. (Health Reports). Trinidad, Bohol: Trinidad RHU.

19Ngoboc, F. (2015). In de Guzman C. (Ed.), Interview with the municipal health officer of

Talibon, Bohol. Manila: Department of Health, Philippines.

20Auza, A. N. (2015). In de Guzman C. (Ed.), Interview with the municipal health officer of

Trinidad, Bohol. Manila: Department of Health, Philippines.

21Lin, D. D., Fau, L. J., Hu, F., Wu, H. W. (0909). Routine Kato-Katz technique underestimates

the prevalence of Schistosoma japonicum: A case study in an endemic area of the

People's Republic of China.

22Hairston, N. G., & Santos, B. C. (1961). Ecological control of the snail host of Schistosoma

japonicum in the Philippines. Bulletin of the World Health Organization, 25(4-5), 603-

610. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2555717/

23Ross, A. G., O. R., Acosta L., Harn, Donald,A., H. D., Chy, D. F., Li Y., Gray, Darren, J., . . .

Williams, G. M. (0707). Road to the elimination of schistosomiasis from Asia: The journey

is far from over [Asia; Control; Elimination; Neglected tropical disease; Schistosomiasis

AID - S1286-4579(13)00152-4 [pii] AID - 10.1016/j.micinf.2013.07.010 [doi].

24Wang, L., Chen, H., Guo, J., Zeng, X., Hong, X., Xiong, J., . . . Zhou, X. (2009). A strategy to

control transmission of schistosoma japonicum in China. N Engl J Med, 360(2), 121-128.

doi:10.1056/NEJMoa0800135

25Fernandez, T., Jr., T. M., Balolong E., Jr., Joseph, L., Joseph L., Willingham,

A.L., 3rd, W. A., Belisle P., Webster, J.P., . . . Carabin, H. (0927). Prevalence of

Schistosoma japonicum infection among animals in fifty villages of Samar province, the

Philippines.

42

APPENDIX

Figure 1. Historical evolution of schistosomiasis control in the Philippines

• 1st case reported 1906

• Recognized as a public health concern 1953

• Schistosoma japonicum regions classified 1975

• Praziquantel introduced • Control shifted from a case-by-case basis to a chemotheraphy-based program

1980

• Intensified case-finding and treatment in all endemic areas 1990

• Decreased financial capacity and support led to loss of control teams in each of the endemic municipalities

• Transition of control program to Mass Drug Administration (MDA)

1995

43

Figure 2A. Map of Bohol and the two endemic municipalities

44

Figure 2B. Map of Talibon with markers for its 4 endemic barangays

45

Figure 2C. Map of Trinidad with markers for its 4 endemic barangays

46

DISEASE  PREVENTION  &  CONTROL  BUREAU  

Infectious  Disease  Of/ice  (IDO)  

Elimination  Division  

Malaria   Rabies  

Leprosy   Neglected  Tropical  Diseases  

Lympathic  Filariasis  

Schistosomiasis  

Prevention  &    Control  Division  

Integrated  Helminth  Control  Program  

Environmental  &  Occupational  Health  

Of5ice  (EOHO)  

Degenerative  Disease  Of5ice  (DDO)  

Family  Health  Of5ice  (FHO)  

Figure 3A. Organizational structure

of schistosomiasis control in the

Philippines’ Department of Health

DEPARTMENT  OF  HEALTH  

Regional  Health  OfWice  

Provincial  DOH  OfWice  

Development  Management  OfWicer  

Provincial  Health  OfWicer  

Municipal  Health  OfWicer  (Rural  Health  

Unit  (RHU))  

Barangay  Health  Station   Midwife  

Public  Health  Nurse  

Sanitation  Inspector  

Medical  Technologist  

Nurse  Deployment  Program  (NDPs)  

Figure 3B. Hierarchical structure of DOH’s administrative system

47

Restituto  B.  Auxtero  ,  CPA

(Municipal  Mayor)

  Dr.  Francisco  C.  Ngoboc,  Jr.

(Municipal  Health  Officer)

  Simplicio  L.  Torreon

(DOH  Representativ

e)

  Mario  Carusos

Provincial  Sanitation  Inspector  I

  Jocelyn  C.  Evangelista

(  M

unicipal  Nurse  )

 

  Jona

 A.  A

lvarez

(  M

unicipal  Nurse  )

  Ma.  Tan

ia  Dolorito

s (  M

unicipal  Nurse  )

   

ZONE  1

Poblacion  RH

M

Eugenia  Jasm

in  (M

idwife  III)

  Sag  RH

M

Editha  Polo  (RHM)

  Nocnocan  RH

M:  

Angelita  Lugod  (RHM)

Charito  Cresencio  (RHM)

  ZONE  3

San  Jose    RHM:

Marivelle  Salicina  (Midwife  II)

  Balitaw

ak    RHM:

Natividad  Abastas  (M

idwife  II)

Madonna  Tidong  (RHM)

    ZONE  5

San  Agustin    RHM:

Cecile  Garcia  (  RHM)

  Zamora    RHM:

Imelda  Bongao  (RHM)

    ZONE  10

Suba  RHM

Lorna  Menesis  (M

idwife  III)

  Busalian  RH

M

Jennelyn  Casam

ayo  (RHM)

  Cataban  RH

M:  

Estrella  Saludo  (RHM)

    ZONE  7

San  Carlos  RHM

Luzviminda  Juntilla  (Midwife  III)

  Sto.  Nino  RH

M

Wellina  Gonzaga  (RHM)

  Sikatuna  RHM:  

Marivic  Rosales  (RHM)

 

  Anecita  P.  Paredes

PHN  (  Nurse  II)

  ZONE  2

San  Francisco    RHM:

Rem

edios  Mum

ar  (M

idwife  III)

Risara  Buri  (RH

M)

  Tangaligue  RHM:

Vivian  Sabior  (RHM)

    ZONE  4

San  Isidro    RHM:

Teresita  Rosales  (M

idwife  II)

  San  Pedro  RH

M:

Rhea  Meijas  (RHM)

    ZONE  6

San  Roque    RHM:

Fredelina  Polestico  (Midwife  II)

  Magsaysay  RHM:

Milquedesa  Deocariza  (RHM)

    ZONE  8

Bagacay    RHM:

Isaida  Garcia  (Midwife  II)

  Burgos  RHM:

Joaniflor  Tubo  (RHM)

  Rizal  RHM:

Neria  Bitoonan  (RHM)

      ZONE  10

Calituban    RHM:

Elsa  Cabugason  (M

idwife  II)

Ana  Mae  Gabison  (RHM)

  Guindacpan  RHM:

Estrella  Torrevillas  (RHM)

  Mahanay  RHM:

Dom

inga  Cabilez(RH

M)

 

  Melchor  Carcallas

Municipal  Sanitation  Inspector  I

Talibon  Municipal  Birthing  

Center

Natividad  Abastas

(  Midwife  II)

Ma.  Concepcion  Lincuna

(Mun.  Nurse)

Charito  Cresencio

(RHM)

Leah  Evangelista

(Mun.  Nurse)

Arlene

 Garcia/  Vicen

ta  Can

tone

s   (Birthing

 Aide)

 

Jhona  Mum

ar

(Clerk)

  Imperatriz  Boiser

(Encoder)

  Gorgonio  Cantones

(Utility/Carpenter)

 

  An

a  Breche

l  A.  Eyas

(San

itatio

n  Aide

)  

  Clau

dio  Evan

gelista

(San

itatio

n  Aide

)  

  Rhoda  Bernales

Microscopist

  Re

na  Ombo

y (Lab

oratory  Aide)

 

NDP  Nurses

  Ariane  N.  Madlangbayan

Jesfer  G.  Ngoboc

Melisa  Mae  B.  Carcallas

Dianne  Zen  A.  Avenido

Lady  Lou  S.  Auguis

Peter  Jane  Q.  Diacor

Jhenlee  B.  Valmores

Fatim

a  Joie  R.  Autentico

Marimar  S.  Salise

  HFEP  Nurse

 

Diona  C.  Auza

Franknel  A.  Ngoboc

Figure 3C. Talibon Municipal Health

Office Organizational Chart (2015).

(Similar to Trinidad)

48

Annex 4: Questionnaire Form 37 Questions 1. Please record the subject's unique ID number. 2. Please record the subject's gender. Choose one response - Male - Female 3. When is your birthdate? 4. What is the highest level of education your parents have completed? Choose one response - Elementary - High School - College - Post graduate or Advance degree - I don't know 5. Which category best describes your annual household income? Choose one response - <5000 pesos - 5000 – 15,000 pesos - 15,000 – 25,000 pesos - 25,000 – 50,000 pesos - 50,000 pesos or more - I don't know 6. Before 2014, how many times did you participate in the annual ‘Mass Drug Administration’ for schistosomiasis (and was administered with praziquantel)? Choose one response - Never - 1 time - 2 times - 3 times - 4 times - 5 times or more - I'm not sure 7. Before 2014, did you know why you took praziquantel? Choose one response - Yes - No If this response, jump to 9 - I'm not sure If this response, jump to 9

8. If yes, please specify. 9. I believe that taking praziquantel will help me prevent from getting infected by schistosomiasis. Choose one response - Yes - No - I'm not sure 10. Before 2014, I had experienced adverse events from taking praziquantel. Choose one response - Yes - No If this response, jump to 13 - I'm not sure If this response, jump to 13 11. If yes, which times? Choose one response - The first year - Every year - It varied 12. Those adverse events included: (Check all that apply.) Choose all that apply - Dizziness - Headache - Malaise - Drowsiness - Fatigue - Abdominal pain - Diarrhea - Vomiting - Nausea - Bodily pain - Fever - Numbness - Others not listed 13. I plan on continuing my participation with the annual MDA as recommended by the Department of Health and as provided and implemented in my local municipality. Choose one response - Yes - No

49

14. At home, what kind of water are you drinking now? Choose one response - Mineral water (e.g. bottled products, delivered water from store) - Boiled water - Tap water (gripo) - Pump/borehole water (poso) - Well water (balon) - Rainwater - Water from stream, creek, or river 15. Before 2014, what was the best available water you drank at home? Choose one response - Mineral water (e.g. bottled products, delivered water from store) - Boiled water - Tap water (gripo) - Pump/borehole water (poso) - Well water (balon) - Rainwater - Water from stream, creek, or river 16. Before 2014, did you have a functional toilet/latrine that you used regularly at home? Choose one response - Yes If this response, jump to 18 - No 17. If not, where did you usually go when you needed to use the bathroom (to defecate/urinate)? (Check all that apply.) Choose all that apply - Communal/shared restroom - Dug pit in the ground - Any open space in the backyard - Closest stream, creek, or river - Anywhere it is convenient 18. What other methods did your family use to dispose of feces? (Check all that apply.) Choose all that apply - In the trash that is collected by the barangay or the municipality - Burned in our backyard - Buried in the ground - In the nearby stream, creek, or river - Thrown anywhere convenient

- Other places not listed above - Not applicable 19. If "Other places..." was selected, please specify. If not, skip this question. 20. Before 2014, did you wash your hands regularly after you use the toilet? Choose one response - Yes - No If this response, jump to 22 21. If yes, did you wash your hands with soap? Choose one response - Yes - No 22. Before 2014, at school, did you wash your hands after you use the toilet? Choose one response - Yes - No If this response, jump to 24 23. If yes, did you wash your hands with soap? Choose one response - Yes - No 24. Before 2014, did you allow any animals or pets (dogs, cats, rats etc.) to roam freely inside and outside your house? Choose one response - Yes - No - Not applicable 25. Before 2014, did you keep any farm animals (e.g. pigs, water buffalos (kalabaw), or cows) in fenced or properly secluded areas? Choose one response - Yes - No - Not applicable 26. Before 2014, did you regularly wash your clothes in creeks, streams, or rivers? Choose one response - Yes

50

- No If this response, jump to 28 27. Please provide the name of the site where you regularly washed your clothes. 28. Before 2014, did you bathe or swim in ponds, creeks, streams, or rivers? Choose one response - Yes - No If this response, jump to 30 29. Please provide the name of the site where you bathed. 30. Before 2014, did you collect water from creeks, streams, or rivers? Choose one response - Yes - No If this response, jump to 32 31. Please provide the name of the site where you collected water. 32. Before 2014, I have seen or notice warning signs about schistosomiasis posted around my community within: Choose one response - The past 6 months - The past year - The past 5 years or more - I don’t remember seeing any 33. Before 2014, I have seen or participated in school advocacy campaigns for schistosomiasis: Choose one response - The past 6 months - The past year - The past 5 years or more - I don’t remember seeing any 34. Before 2014, I have seen or notice advertisements about schistosomiasis on one or more of the following mediums: (Check all that apply.) Choose all that apply - TV - Radio - Magazine - Newspaper - Internet - None of the above - Others not listed above 35. If "Others..." was selected, please specify. If not, skip this question.

36. Scan your GPS coordinates. 37. End of Survey. Thank you for participating!