Transcript Vector-Borne & Water

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)
b)
c)
Malaria
Dengue Fever
West Nile Virus
Question #3
Describe 5 ways that the spread of vectorborne diseases can be prevented:
Question #4
Which water-borne disease is also known
as “the brain-eating ameoba”?
a)
b)
c)
Cholera
Norovirus
Naegleria Fowleri
Question #5
Describe 5 ways that the spread of waterborne diseases can be prevented:
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 vectorborne 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
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Mild Symptoms:
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
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Severe Symptoms

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
Fever
Headaches
Nausea and vomiting
Body aches
Neurologic abnormalities
Severe anemia
Low blood pressure
Acute 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
U.S. Disease Vulnerability 1995-2005

Mild Symptoms:
 Joint pain
 Rash

Severe Symptoms:
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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.
West Nile Virus

Vector: Mosquito
Preliminary July 2013 WNV Activity (CDC)

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
West Nile Virus: Symptoms & Outcomes
70-80% of those who become
infected will not experience any
symptoms
 Mild Symptoms (20%):




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

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
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Mild Symptoms:
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Swollen lymph glands
Fever
Headache
Chills
Weakness
Severe Symptoms:
 Progress into
Pneumonic Plague

Possible Outcomes:
 Death
Image 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 vectorborne 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

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
 vomiting
 leg cramps

Possible Outcomes:
 dehydration
 shock
 death
Image Source: CDC
Norovirus

Transmission:
 infected person to person
 contaminated 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:

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
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

diarrhea
vomiting
nausea
stomach pain
fever
headache
body aches
Possible Outcomes:
 Dehydration
 Death
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
Image Source: CDC
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

Naegleria Fowleri: Symptoms & Outcomes

Mild Symptoms:






Severe Symptoms:






Headache
Fever
Nausea
Vomiting
stiff neck
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)

Question #1
Name three climatic factors that influence
the survival rates and range of vectors:
1.
2.
3.
Temperature
Precipitation
Humidity
Question #2
Which vector-borne disease is transmitted via
the Asian Tiger mosquito?
a)
b)
c)
Malaria
Dengue Fever
West Nile Virus
Question #3
Describe 5 ways that the spread of vectorborne 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)
b)
c)
Cholera
Norovirus
Naegleria Fowleri
Question #5
Describe 5 ways that the spread of water
borne diseases can be prevented:
1)
2)
3)
4)
5)
6)
7)
8)
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)
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