Toxoplasma gondiiChristina Drazan

Geographic Distribution

Worldwide, one of the most common human infections

More common in warm climates High prevalence in France and C. America

High prevalence in France seems to be due to the preference for eating raw or undercooked meat

In C. America, it seems to be related to the frequency of stray cats in a climate favoring survival of oocysts and soil exposure

Definitive Host/Intermediate

Host Cats are the only definitive host It can infect nearly all warm-blooded

animals but they are considered intermediate hosts

Life Cycle

T. gondii

T. gondii Cyst in the Brain

Sites of Infection Definitive host – breeds in the small

intestine, Vector– travels in the blood and attacks

other tissues http://animal.discovery.com/videos/monsters

-inside-me-toxoplasma-parasite.html

Pathogensis/Clinical Signs

In cats Anorexia Weight loss Lethargy Labored breathing Ocular signs Fever

Pathogensis/Clinical Signs

In humans Most do not have symptoms 10-20% develop sore nodes and muscle pains that eventually go

away Once infected, always infected Go dormant as tissue cysts but reactivate when a person becomes

sick with another disease or takes immunosuppressive drugs Can cause blindness if the parasite reaches the eye If a woman is infected during pregnancy, she can transmit the

disease to her unborn child This can cause:

A miscarriage or stillborn baby The baby can be born with signs of toxoplasmosis (ex.

Abnormal enlargement or smallness of head) The baby could have brain or eye damage which can develop

later in life

Diagnosis Is typically made by serologic tests by

detecting immunoglobulin antibodies within several weeks of infection (in both humans and cats)

Living parasites can also be found in a sample of blood, cerebrospinal or other body fluids but the process is more difficult so rarely used

Congenital infections – detecting T. gondii DNA in amniotic fluid using molecular methods such as PCR

Treatment for Humans Combinations of pyrimethamine with

Trisulfapyrimidines or sulfadiazine Folinic acid in the form of leucovorin calcium to protect

the bone marrow from the toxic effects of pyrimethamine

Combination of sulfamethoxazole and trimethoprim For pregnant women

First four months – spiramycin After four months – sulfadizain/pyrimethamine and

folinic acid Congenitally infected babies are treated with

sulfonamide and pyrimethamine

Treatment for Cats Antibiotic called Clindamycin Pyrimethamine with sulfadizine

Control Measures Do not allow cats to hunt or roam Do not eat raw or undercooked meat, and don’t

drink water from the environment Keep your cat from using the garden or children’s

play area (i.e. sandbox) as a litter box Remove feces from litter box daily, and wash

hands after Pregnant women should not clean the litter box Control rodent populations and other potential

intermediates