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Zoonotic Parasites
Copyright 2010. PEER.tamu.edu
What are zoonotic diseases

According to the CDC* a zoonotic disease is any
disease which may be passed from animals to people
or from people to animals.
CDC: U.S. Communicable Disease Center
Zoonotic Diseases
Approximately 60% of all human
pathogens are zoonotic
 75% of emerging infectious diseases
have an animal origin
 Growing need for veterinarians and
physicians to work together

Causes of Zoonotic Disease
Bacteria
Fungi
Virus
Parasites
Parasites and Animals

Many methods of parasite transmission
to people involve animals
Can you name some animal
parasites?
Vector-borne Parasites
A vector is an agent which transfers a
parasite from one host to another
 Typical parasite vectors: fleas, ticks,
mites, mosquitoes, flies, and other
insects
 People become infected when a vector
picks up the parasite from an infected
animal and infects a human

Parasites carried by Vectors

Many parasites that are carried by
vectors are often found in the blood of
humans and animals
Trypanosoma Cruzi

Causes Chagas disease.
 Damage to heart, digestive tract, and brain (in
children).
 Spread by the “Kissing Bug,”
native to South America and the southern US
 The bug bites the human then defecates next to the
wound. Rubbing bite wound spreads parasite into the
wound.
 Parasite can cycle from animals like armadillos,
raccoons, opossums, and foxes to bugs to humans.
Chagas Disease & The “Kissing
Bug”
Trypanosoma cruzi
in the blood
Don’t Kiss
ME!!!
Kissing Bug found
in Texas
Babesia
Intracellular protozoa found in red blood
cells
If you play
around trees,
 Spread by infected Ticks

check your head
and body for
me!!
DID YOU KNOW?
Texas A&M University College of
Veterinary Medicine was started to stop
the spread of the Cattle Fever Tick.
 The causative agent was a species of
Babesia that the ticks were spreading to
Texas cattle.
Thanks
TEXAS A&M!!
Leishmania
Unlike Babesia and Chagas Disease,
Leishmania live in tissue and not the
blood
 Spread through the bite of an infected
Sandfly*

*common on Caribbean beaches
Leishmania
Human foot
Waterborne Parasites
Spread when humans come into contact
with water that has been contaminated
by an infected animal
 Common waterborne parasites include

Giardia
 Cryptosporidium

Giardia & Cryptosporidium
Giardia & Cryptosporidium




Get from swallowing water contaminated by
another infected human or animal
Giardia is the 2nd most common parasitic
disease in people
Cryptosporidium is the most common
cause of diarrhea from swimming
Both can cause severe diarrhea
Gross!!! Don’t
drink the water
your swimming
in!!!
How Do People Get Parasites
Methods of Parasite
Transmission








I need to
WASH MY
HANDS!!!
Insect bites
Animal feces
Handling raw meat and fish
Handling cat litter boxes
Contaminated fruits and vegetables
Infected food handlers
Contaminated water
Contact with an infected person
Broad Categories of Transmission
Vectorborne (insects)
 Waterborne
 Fecal Oral Transmission
 Contaminated Meat

Fecal-Oral Transmission
Most common way people become
infected with zoonotic parasites
 Parasites are spread to humans when
they ingest the eggs from the feces of an
infected animal
I don’t feel
so good
 Parasites spread by fecal oral
transmission generally live in the
intestinal tract

Spread by Fecal Oral Transmission
Hookworms
 Roundworms
 Hydatid Disease
 Toxoplasmosis

Hookworms & Roundworms
They are like
monsters!!!!
Hookworms & Roundworms

Carried by dogs and
cats
 Kids often get
infected from playing
in sand boxes which
animals have
defecated
 Or by putting toys in
their mouth which
have been on the
ground
Hookworms

Can penetrate the
skin and gain entry
into the human body
 Bare feet are a
common route of
entry
Wearing shoes is one of the
best ways to prevent
parasites from entering your
feet!!!
Hydatid Disease

After Humans consume the eggs passed
by dogs the worms can form huge cysts
in the body
Toxoplasmosis


How many have of you
have heard that
pregnant women
shouldn’t clean cat litter
boxes?
That is because of the
potential for them to
contract Toxoplasmosis
which can cause them to
lose their unborn child.
Toxoplasmosis
Even though it is commonly associated
with pregnancy and litter boxes,
toxoplasmosis is more commonly
transmitted through undercooked meat
 According to the CDC toxoplasmosis is
the 3rd leading cause of foodborne
Order your
related deaths in the US
food to be

cooked all the
way!!
Contaminated Meat
Meat can be contaminated with harmful
bacteria and can also contain parasitic
cysts which may infect people.
 Common Parasites Found in Meat

Toxoplasmosis
 Trichinella
 Taenia
 Gnathostomosis

Trichinosis & Taenia

Both caused by
eating cysts in
undercooked pork or
beef
 Incidence rate has
decreased with
better animal
management and
slaughter protocol
 Fully cook your
meat!
Cysticercosis

If a person
consumes Taenia
eggs they can
develop cysts in their
brain!
Gnathostomosis
Similar to Taenia and Trichonosis, but
gnathostomosis is found in raw fish
 What area do you think this disease is
most common?
Asia

Summary

Zoonotic parasites have many routes of
transmission to people
Vectors
 Water
 Fecal Contamination
 Infected Meat

So How Can You Protect
Yourself?
Preventing Zoonotic Parasites

Brainstorm some ways we can prevent
them…

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Always wash your hands
Keep sand boxes covered
Wear shoes
Pick up animal feces when possible
Don’t drink untreated water
Cook meat thoroughly
References
http://www.dpd.cdc.gov/DPDx/default.ht
m
 http://cal.vet.upenn.edu/projects/dxendo
par/index.html
 www.nih.gov
 www.nsf.gov
 www.floridahealthfinder.gov
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