Dengue: A Global ThreatAudience: United States International Travelers

Arkia Blackman, MPH student Walden University

PUBH 6165-5 Environmental HealthInstructor: Dr. Donald Goodwin

Spring, 2010

AgendaAgenda

Definition Definition Modes of TransmissionModes of Transmission SerotypesSerotypes ClassificationClassification Contributing factorsContributing factors StatisticsStatistics PreventionPrevention TreatmentTreatment Tips for travelersTips for travelers Blood transfusionBlood transfusion

DefinitionDefinition

What is Dengue?What is Dengue?

Dengue is a virus consisting of a single-stranded Dengue is a virus consisting of a single-stranded Ribonucleic Acid (RNA) Ribonucleic Acid (RNA) (Thomas, John & Kanish(Thomas, John & Kanish,, 2010). 2010).

The virus genetic makeup consist of a lipid The virus genetic makeup consist of a lipid envelope protein that enables it to transport and envelope protein that enables it to transport and

bind in possible hosts bind in possible hosts (Teo, Ng & Lam, 2009).(Teo, Ng & Lam, 2009).

Modes of TransmissionModes of Transmission

Vector borne transmissionVector borne transmission• MosquitoMosquito

Non vector borne transmission Non vector borne transmission • Mother to child Mother to child (Wiwanitki, 2010).(Wiwanitki, 2010).

• Blood transfusion Blood transfusion (Wiwanitki, 2010).(Wiwanitki, 2010).

• Organ transplantation Organ transplantation (Wiwanitki, 2010).(Wiwanitki, 2010).

Mode of TransmissionMode of Transmission

Aedes AegyptiAedes Aegypti (Teo et al., 2009)(Teo et al., 2009)

Aedes albopictus Aedes albopictus (Teo et al., 2009)(Teo et al., 2009)

Aedes polynesiensis Aedes polynesiensis (Teo et al., 2009)(Teo et al., 2009)

Modes of TransmissionModes of Transmission Dengue is transmitted primarily by the mosquito Dengue is transmitted primarily by the mosquito

family family Aedes Aegypti Aedes Aegypti ((Teo et al., 2009).Teo et al., 2009).

Dengue can also be transmitted by mosquito Dengue can also be transmitted by mosquito family family Aedes albopictusAedes albopictus and and AedesAedes polynesiensispolynesiensis (Teo et al., 2009). (Teo et al., 2009).

A female mosquito bite leads to an infection of A female mosquito bite leads to an infection of Dengue then is transmitted into other victims in a Dengue then is transmitted into other victims in a constant cycle. constant cycle.

The incubation period of the infection varies 7-14 The incubation period of the infection varies 7-14 daysdays (Teo et al., 2009). (Teo et al., 2009).

The mosquito biting period occurs primarily in the The mosquito biting period occurs primarily in the dawn and at duskdawn and at dusk (Teo et al., 2009). (Teo et al., 2009).

Modes of TransmissionModes of Transmission

Mother to child transmissionMother to child transmission• Can occur during a woman’s late term of their Can occur during a woman’s late term of their

pregnancy through the placenta pregnancy through the placenta (Wiwanitki,(Wiwanitki, 2010).2010).

Transmission through transfusion of blood and Transmission through transfusion of blood and blood products blood products (Wiwantiki, 2010).(Wiwantiki, 2010).

Transplantation of Dengue infected organsTransplantation of Dengue infected organs (Wiwantiki, 2010). (Wiwantiki, 2010).

SerotypesSerotypes There are four serotypes of dengue There are four serotypes of dengue (Teo et al., 2009).(Teo et al., 2009).

• Den-1Den-1• Den-2Den-2• Den-3Den-3• Den-4Den-4

Infection of one serotype does not ensure Infection of one serotype does not ensure immunity against the other serotypes immunity against the other serotypes (Teo et al., 2009). (Teo et al., 2009).

The serotypes are independent of each other The serotypes are independent of each other (Teo (Teo et al., 2009). et al., 2009).

ClassificationClassification

Dengue feverDengue fever • Classified as individuals with symptoms such as Classified as individuals with symptoms such as

headache, rash, leukopenia or myalgia along headache, rash, leukopenia or myalgia along with the serological confirmation or in an areawith the serological confirmation or in an area with similarwith similar cases cases (Thomas et al., 2010). (Thomas et al., 2010).

Dengue hemorrhagic feverDengue hemorrhagic fever• Classified by a previous or current fever lasting Classified by a previous or current fever lasting

2-7 days, bleeding such as hematemesis, a high 2-7 days, bleeding such as hematemesis, a high thrombocytopenia count, and evidence of plasma thrombocytopenia count, and evidence of plasma leakage leakage (Thomas et al., 2010).(Thomas et al., 2010).

Dengue shock syndromeDengue shock syndrome• Classified as having all the symptoms of dengue Classified as having all the symptoms of dengue

hemorrhagic fever and failure to the circulatory hemorrhagic fever and failure to the circulatory system system (Thomas et al., 2010). (Thomas et al., 2010).

Contributing FactorsContributing Factors

Population growth Population growth (Teo et al., 2009)(Teo et al., 2009)

Ineffective mosquito control Ineffective mosquito control (Teo et al., 2009)(Teo et al., 2009)

Global travel Global travel (Teo et al., 2009)(Teo et al., 2009)

Poor water management Poor water management (Teo et al., 2009)(Teo et al., 2009)

StatisticsStatistics 2.5 billion individuals are at risk globally 2.5 billion individuals are at risk globally

(CDC, 2010).(CDC, 2010).

100 million individuals become affected 100 million individuals become affected with dengue fever annually with dengue fever annually (CDC, 2010)(CDC, 2010)

Children make up the majority of the Children make up the majority of the 500,000 cases of the fatal dengue 500,000 cases of the fatal dengue

hemorrhagic fever hemorrhagic fever (CDC, 2010).(CDC, 2010).

StatisticsStatistics

Dengue is the second highest disease among Dengue is the second highest disease among travelers hospitalized after travel to tropical areas travelers hospitalized after travel to tropical areas (Tomashek, 2009)(Tomashek, 2009)

Individuals that travel to dengue-endemic countries Individuals that travel to dengue-endemic countries suffer an infection rate of 2.9% to 8% suffer an infection rate of 2.9% to 8% (Tomashek, 2009)(Tomashek, 2009)

Dengue is the number one disease for individuals Dengue is the number one disease for individuals that travel to South Central Asia, Southeast Asia, that travel to South Central Asia, Southeast Asia, Caribbean and South America Caribbean and South America (Tomashek, 2009).(Tomashek, 2009).

PreventionPrevention

Environmental control involves reducing or Environmental control involves reducing or eliminating breeding grounds for mosquitoes by eliminating breeding grounds for mosquitoes by properly managing solid waste inproperly managing solid waste in a community a community or country or country (Gurugama, Garg, Perera, Wijewickrama & Seneviratne, (Gurugama, Garg, Perera, Wijewickrama & Seneviratne,

2010).2010).

Chemical control involves the use of insecticides Chemical control involves the use of insecticides to target the larvae state of mosquito lifecycle or to target the larvae state of mosquito lifecycle or thermal fogging which is a form of spraying in thermal fogging which is a form of spraying in

the householdthe household (Gurugama et al., 2010).(Gurugama et al., 2010).

NO VACCINE AVAILABLE NO VACCINE AVAILABLE

TreatmentTreatment

Dengue without warning signsDengue without warning signs• Treatment include proper bed rest, Treatment include proper bed rest,

replenishment of fluids and proper dosage of replenishment of fluids and proper dosage of

the drug Paracetamolthe drug Paracetamol (World Health Organization [WHO], (World Health Organization [WHO], 2009). 2009).

Dengue with warning signsDengue with warning signs

• Treatment include fluid therapy as prescribedTreatment include fluid therapy as prescribed by medical personnelby medical personnel (WHO, 2009).(WHO, 2009).

Severe DengueSevere Dengue• Treatment consist of fluid resuscitation with Treatment consist of fluid resuscitation with

isotonic crystalloid solutionsisotonic crystalloid solutions (WHO, 2009).(WHO, 2009).

PreventionPrevention

Vaccines are being created and are in clinical Vaccines are being created and are in clinical studies so that they can be tested and researched studies so that they can be tested and researched

for safety and effectivenessfor safety and effectiveness (Guzman, Vazquez & Kouri, (Guzman, Vazquez & Kouri, 2009)2009)

Some issues with creating vaccines include the Some issues with creating vaccines include the differences between the four serotypes which differences between the four serotypes which may require different types of vaccine instead of may require different types of vaccine instead of

one and the lack of an animal researchone and the lack of an animal research subjectsubject (Guzman et al. 2009)(Guzman et al. 2009)

Tips for TravelersTips for Travelers Sleeping accommodations Sleeping accommodations

• Travelers should ensure they are staying in Travelers should ensure they are staying in accommodations that have air conditioning accommodations that have air conditioning available and windows are appropriately available and windows are appropriately screened screened (Tomashek, 2009)(Tomashek, 2009). .

Clothing Clothing • Travelers should wear clothing that protects Travelers should wear clothing that protects

exposed areas such as legs and arms to ensure exposed areas such as legs and arms to ensure mosquitoes do not have easymosquitoes do not have easy access to bite and access to bite and transmit the dengue virustransmit the dengue virus (Tomashek, 2009). (Tomashek, 2009).

Insect RepellantInsect Repellant• Repellant is very important and necessary when Repellant is very important and necessary when

traveling to areas that are endemic to dengue. traveling to areas that are endemic to dengue. The repellant should be used on clothes and The repellant should be used on clothes and areas of the skin areas of the skin (Tomashek, 2009). (Tomashek, 2009).

Blood TransfusionsBlood Transfusions Donor qualificationDonor qualification

• Due to the rise of dengue infection in endemic Due to the rise of dengue infection in endemic countries and among travelers the individuals countries and among travelers the individuals can be deferred from donating blood to prevent can be deferred from donating blood to prevent the risk of transfusion related transmissionthe risk of transfusion related transmission of of denguedengue (Teo et al., 2009)(Teo et al., 2009). .

• In various countries blood donors are being In various countries blood donors are being deferred for 6 months and 2-3 weeks and this deferred for 6 months and 2-3 weeks and this diminishes the number of blood donations diminishes the number of blood donations available for emergency and routine useavailable for emergency and routine use (Teo et al., (Teo et al., 2009). 2009).

NAT testingNAT testing• The cost of NAT testing for dengue will be The cost of NAT testing for dengue will be

expensive and necessary to detect dengue in expensive and necessary to detect dengue in blood donations to ensure there is a safe blood blood donations to ensure there is a safe blood supply supply (Teo et al., 2009).(Teo et al., 2009).

SummarySummary Dengue is a virus transmitted by vector and non Dengue is a virus transmitted by vector and non

vector methodsvector methods

There are 3 types of dengue disease, dengue There are 3 types of dengue disease, dengue fever, dengue hemorrhagic fever and dengue fever, dengue hemorrhagic fever and dengue shock syndromeshock syndrome

TravelersTravelers need to protect themselves when need to protect themselves when traveling to prevent infection of dengue traveling to prevent infection of dengue

No vaccine is available for use currentlyNo vaccine is available for use currently

Blood donations are at riskBlood donations are at risk

QuestionsQuestions

ReferencesReferencesCenter for Disease Control. (2010). Dengue-ACenter for Disease Control. (2010). Dengue-AWorldwide Threat. The Dengue Update. Volume 1.Worldwide Threat. The Dengue Update. Volume 1.Retrieved on April 24, 2010, fromRetrieved on April 24, 2010, fromhttp://www.cdc.gov/dengue/dengue_upd/index.htmlhttp://www.cdc.gov/dengue/dengue_upd/index.html

Gurugama, P., Garg, P., Perera, J., Wijewickrama, A., &Gurugama, P., Garg, P., Perera, J., Wijewickrama, A., &Seneviratne S. L. (2010). Dengue Viral InfectionsSeneviratne S. L. (2010). Dengue Viral Infections. Indian. IndianJournal of Dermatology, Journal of Dermatology, 55(1), 68-78. DOI: 10.4102/001955(1), 68-78. DOI: 10.4102/00195154.60357. 5154.60357.

Guzman M. G., Vazquez, S. & Kouri, G. (2009). Dengue:Guzman M. G., Vazquez, S. & Kouri, G. (2009). Dengue:where are we today? where are we today? Malaysian Journal of Medical Sciences,Malaysian Journal of Medical Sciences,16(3), 5-12. Retrieved from Academic Search Complete Database16(3), 5-12. Retrieved from Academic Search Complete Database

Teo D., Ng L. C., & LamTeo D., Ng L. C., & Lam, S. , S. (2009). Is dengue a threat to the(2009). Is dengue a threat to theblood supply? blood supply? Transfusion MedicineTransfusion Medicine, 19, 66-77. doi:, 19, 66-77. doi:10.111/j.1365-3148.2009.00916.x10.111/j.1365-3148.2009.00916.x

References References Thomas E. A., John, M., & Kanish B. (2010).Thomas E. A., John, M., & Kanish B. (2010).Mucocutaneous Manifestations of Dengue Fever.Mucocutaneous Manifestations of Dengue Fever.Indian Journal of Dermatology, Indian Journal of Dermatology, 55(1), 79-85. DOI:55(1), 79-85. DOI:10.4103/0019-5154.60359.10.4103/0019-5154.60359.

Tomashek, K. M. (2009). Dengue Fever (DF) andTomashek, K. M. (2009). Dengue Fever (DF) andDengue Hemorrhagic Fever (DHF). Retrieved AprilDengue Hemorrhagic Fever (DHF). Retrieved April25, 2010, from 25, 2010, from

http://wwwnc.cdc.gov/travel/yellowbook/2010/chapthttp://wwwnc.cdc.gov/travel/yellowbook/2010/chapter-5/dengue-fever-dengue-hemorrhagic-fever.aspxer-5/dengue-fever-dengue-hemorrhagic-fever.aspx

Wiwanitkit, V. (2010). Non vector-borne transmissionWiwanitkit, V. (2010). Non vector-borne transmissionmodes of dengue. modes of dengue. Journal of Infection In DevelopingJournal of Infection In DevelopingCountriesCountries, 4(1), 051-054. Retrieved from Academic Search, 4(1), 051-054. Retrieved from Academic SearchComplete Database.Complete Database.

ReferencesReferences

World Health Organization. (2009). DengueWorld Health Organization. (2009). Dengue

Guidelines for Diagnosis,Treatment, Prevention and Control.Guidelines for Diagnosis,Treatment, Prevention and Control.

Retrieved April 24, 2010, fromRetrieved April 24, 2010, from

http://whqlibdoc.who.int/publications/2009/97892 1547871_enhttp://whqlibdoc.who.int/publications/2009/97892 1547871_eng.pdfg.pdf

Sources to ReadSources to Read

For information on insect repellants such as how to use them, For information on insect repellants such as how to use them, when to use and why to use them check out the following sitewhen to use and why to use them check out the following site• Centers for Disease Control and Prevention. Insect Centers for Disease Control and Prevention. Insect

RepellentRepellentUse and Safety; [updated 2008 May 14; cited 2008 Nov Use and Safety; [updated 2008 May 14; cited 2008 Nov 29]. Available from:29]. Available from:

www.cdc.gov/ncidod/dvbid/westnile/qa/insect_repellent.htmwww.cdc.gov/ncidod/dvbid/westnile/qa/insect_repellent.htm. .

For additional information on insect repellants and which ones For additional information on insect repellants and which ones are registered and unregistered and alternative preventative are registered and unregistered and alternative preventative measures please visit this site on the U.S. Environmental measures please visit this site on the U.S. Environmental Protection AgencyProtection Agency• U.S. Environmental Protection Agency. How to Use InsectU.S. Environmental Protection Agency. How to Use Insect

Repellents Safely; [updated 2007 July 5; cited 2008 Repellents Safely; [updated 2007 July 5; cited 2008 Nov Nov 29]. Available from:29]. Available from:

www.epa.gov/pesticides/health/mosquitoes/insectrp.htmwww.epa.gov/pesticides/health/mosquitoes/insectrp.htm. .

Sources to ReadSources to Read

For information on the research being conducted to create For information on the research being conducted to create a vaccine and the progress and challenges of this effort a vaccine and the progress and challenges of this effort please read the following articleplease read the following article• Swaminathan, S. & Khanna, N. (2010). Dengue vaccineSwaminathan, S. & Khanna, N. (2010). Dengue vaccine

current progress and challenges. Current Science. current progress and challenges. Current Science. 98(3):369-37898(3):369-378