VECTOR-BORNE & WATER-BORNE

DISEASES

PRE-QUIZ

Question #1

Name three climatic factors that influence

the survival rates and range of disease vectors:

Question #2

Which vector-borne disease is transmitted via

the Asian Tiger mosquito?

a) Malaria

b) Dengue Fever

c) West Nile Virus

Question #3

Describe 5 ways that the spread of vector-borne diseases can be prevented:

Question #4

Which water-borne disease is also known

as “the brain-eating ameoba”?

a) Cholera

b) Norovirus

c) Naegleria Fowleri

Question #5

Describe 5 ways that the spread of water-borne diseases can be prevented:

Vector-Borne Diseases

What is a Vector-Borne Disease?

Vectors are insects (mosquitoes, ticks, fleas, black flies and sandflies) that carry infectious agents such as protozoa, bacteria and viruses.

They carry and transmit numerous diseases to humans: parasitic vector-borne diseases, arboviral diseases, and bacterial and rickettsial diseases

Climate Change Promotes Vector-borne Disease

Warmer temperatures

Increased precipitation

Increased humidity

Malaria Vector: Mosquito

Transmission: Bite from an infected mosquito

Prevalence: Estimated 219 million cases of malaria worldwide, resulting in the deaths of approximately 660,000 people.

US Prevalence: An average of 1,500 reported cases of malaria in the U.S. each year.

Global Prevalence of Malaria (CDC)

Malaria: Symptoms & Outcomes Mild Symptoms:

FeverHeadachesNausea and vomitingBody aches

Severe SymptomsNeurologic abnormalitiesSevere anemiaLow blood pressureAcute kidney failure

Possible Outcomes:Acute respiratory distress

syndrome death

Dengue Fever Vector: Asian tiger mosquito, which

can be found in 36 states in the U.S.

Transmission: Bite from an infected mosquito

Prevalence: 100 million cases of dengue worldwide each year. The disease is now endemic in many countries of the Americas.

US Prevalence: Occurs rarely, but there is a small risk for dengue outbreaks in the continental United States.

Dengue Fever: Symptoms & Outcomes Mild Symptoms:

Joint pain Rash

Severe Symptoms: Severe headache severe pain behind the eyes muscle and bone pain mild bleeding persistent vomiting severe abdominal pain difficulty breathing

Possible Outcomes: If not treated, this may lead to

failure of the circulatory system and shock, and eventually death.

U.S. Disease Vulnerability 1995-2005

West Nile Virus Vector: Mosquito

Transmitted: Bite from an infected mosquito

Prevalence: WNV is commonly found in Africa, Europe, the Middle East, North America and West Asia.

U.S. Prevalence: Between 1999 and 2012, about 37,000 cases of West Nile Virus were reported in the U.S. Over 1,500 people died as a result.8

Preliminary July 2013 WNV Activity (CDC)

West Nile Virus: Symptoms & Outcomes 70-80% of those who become infected

will not experience any symptoms Mild Symptoms (20%):

fever headache body aches joint pains vomiting diarrhea rash

Severe Symptoms (<1%): encephalitis meningitis coma paralysis

Global Prevalence of WNV

Bubonic Plague Vector: Fleas

Transmission: Bite from an infected flea, contact with contaminated fluid or tissue, infectious droplets

Prevalence: 1,000 - 2,000 cases each year

U.S. Prevalence: 999 cases in the U.S. between 1900 and 2010. Cases in the U.S. have shifted northward as temperatures have warmed.

Bubonic Plague: Symptoms & Outcomes Mild Symptoms:

Swollen lymph glandsFeverHeadacheChillsWeakness

Severe Symptoms:Progress into

Pneumonic Plague Possible Outcomes:

DeathImage source: CDC

Lyme Disease Vector: Deer tick

Transmission: Bite from an infected deer tick

Prevalence: Areas of Asia, north-western, central and eastern Europe, and the USA.

U.S. Prevalence: Most commonly reported vector-borne illness in the United States, heavily concentrated in the Northeast and upper Midwest.

Lyme Disease: Symptoms & Outcomes 3 – 30 days: Bulls eye rash,

Fatigue, Chills, Fever, Headache, muscle and joint aches, swollen lymph nodes

Days to weeks: Additional Bulls eye rash, facial or Bell's palsy, severe headaches and neck stiffness due to meningitis, pain and swelling in the large joints

Months to years: arthritis, severe joint pain and swelling.

Image courtesy of CDC Division of Vector-Borne Infectious Diseases

Prevention: Vector-borne Disease Avoid areas with vector-borne

disease outbreaks Be aware of peak exposure times and

places Wear long sleeves and pants Check for ticks Bed nets Insecticides and spatial repellents

Water-Borne Diseases

What is a Water-Borne Disease? “Pathogenic microbes that

can be directly spread through contaminated water.” -CDC

Humans contract waterborne infections by contact with contaminated water or food.

May result from human actions, such as improper disposal of sewage wastes, or extreme weather events like storms and hurricanes.

Climate Change Promotes Water-borne Disease

Rainfall: transport and dissemination of infectious agents

Flooding: sewage treatment plants overflow; water sources contaminated

Sea level rise: enhances risk of severe flooding

Higher temperatures: Increases growth and prolongs survival rates of infectious agents

Drought: increases concentrations of pathogens, impedes hygiene

Cholera Found in water or

food sources contaminated by feces from an infected person

Transmitted by contaminated food, water

Prevalence increases with increasing temperature and rainfall amounts

Global Prevalence of Cholera (WHO)

Cholera: Symptoms & Outcomes Often mild or without

symptoms Severe Symptoms (5%):

diarrhea vomitingleg cramps

Possible Outcomes:dehydrationshockdeath

Image Source: CDC

Norovirus

Transmission:infected person to personcontaminated food or water contaminated surfaces

Causes ~ 21 million illnesses, contributes to about 70,000 hospitalizations and 800 deaths each year.

Most common cause of acute gastroenteritis in the United States

Norovirus: Symptoms & Outcomes

Symptoms:diarrheavomitingnauseastomach painfeverheadachebody aches

Possible Outcomes: DehydrationDeath

Norovirus: Cases

Hurricane Katrina Breakout occurred

between Sept 2-12 in Houston, TX

1,169 evacuees contracted the norovirus after Hurricane Katrina due to contaminated water

Naegleria Fowleri

Commonly referred to as the "brain-eating amoeba" Causes an infection of the brain Found in warm freshwater and soil Transmitted when contaminated water enters the

body through the nose

Image Source: CDC

Naegleria Fowleri: Symptoms & Outcomes Mild Symptoms:

Headache Fever Nausea Vomiting stiff neck

Severe Symptoms: confusion lack of attention to people and surroundings loss of balance seizures hallucinations

Possible Outcome: death

Naegleria Fowleri: Cases

Due to its need for high temperatures, the range of naegleria fowleri was once thought to be limited to lower latitudes.

However, warmer temperatures and extreme weather events that may be linked to climate change have allowed conditions necessary for naegleria fowleri to expand northward.

1 death was recorded in Minnesota in 2010.

Prevention: Water-borne Disease Improve quality and quantity of drinking water at

source, at the tap, or in the storage vessel Interrupt routes of transmission by emptying

accumulated water sources Chlorinate water Change hygiene behavior (ex. Hand washing) Take care in disposing of waste and human and animal

feces Proper use of latrines by adults and children Proper use and maintenance of water supply,

sanitation systems, pumps and wells Good food hygiene (ex. protect food from flies)

POST-QUIZ

Question #1

Name three climatic factors that influence

the survival rates and range of vectors:

1. Temperature

2. Precipitation

3. Humidity

Question #2

Which vector-borne disease is transmitted via

the Asian Tiger mosquito?

a) Malaria

b) Dengue Fever

c) West Nile Virus

Question #3

Describe 5 ways that the spread of vector-

borne diseases can be prevented:

1) Avoid areas with disease outbreaks

2) Be aware of peak exposure times and places

3) Wear long sleeves and pants

4) Check for ticks

5) Bed nets

6) Insecticides and spatial repellents

Question #4

Which waterborne disease is also known

as “the brain-eating ameoba”?

a) Cholera

b) Norovirus

c) Naegleria Fowleri

Question #5

1) Improve quality and quantity of drinking water at source, at the tap, or in the storage vessel

2) Interrupt routes of transmission by emptying accumulated water sources

3) Chlorinate water

4) Change hygiene behavior (ex. Hand washing)

5) Take care in disposing of waste and human and animal feces

6) Proper use of latrines by adults and children

7) Proper use and maintenance of water supply, sanitation systems, pumps and wells

8) Good food hygiene (ex. protect food from flies)

Describe 5 ways that the spread of water borne diseases can be prevented:

Join Together for Change

www.PSR.org 202-667-4260