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

Virus

Parasites

Fungi

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”

Kissing Bug found in Texas

Trypanosoma cruzi in the blood

Don’t Kiss ME!!!

Babesia

Intracellular protozoa found in red blood cells

Spread by infected TicksIf you play

around trees, 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 includeGiardiaCryptosporidium

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

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

I need to WASH MY HANDS!!!

Broad Categories of Transmission

Vectorborne (insects)WaterborneFecal Oral TransmissionContaminated 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

Parasites spread by fecal oral transmission generally live in the intestinal tract

I don’t feel so good

Spread by Fecal Oral Transmission

HookwormsRoundworms Hydatid DiseaseToxoplasmosis

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 related deaths in the US Order your

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 MeatToxoplasmosisTrichinellaTaeniaGnathostomosis

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 peopleVectorsWaterFecal Contamination Infected Meat

So How Can You Protect Yourself?

Preventing Zoonotic Parasites

Brainstorm some ways we can prevent them… 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.htm

http://cal.vet.upenn.edu/projects/dxendopar/index.html

www.nih.govwww.nsf.govwww.floridahealthfinder.gov