Transcript Toxoplasma gondii

Toxoplasma gondii
Christina Drazan
Geographic Distribution
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Worldwide, one of the most common human
infections
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More common in warm climates
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High prevalence in France and C. America
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High prevalence in France seems to be due to the
preference for eating raw or undercooked meat
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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
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Cats are the only definitive host
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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
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Definitive host – breeds in the small intestine,
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Vector– travels in the blood and attacks other tissues
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http://animal.discovery.com/videos/monstersinside-me-toxoplasma-parasite.html
Pathogensis/Clinical Signs
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In cats
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Anorexia
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Weight loss
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Lethargy
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Labored breathing
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Ocular signs
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Fever
Pathogensis/Clinical Signs
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In humans
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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
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Is typically made by serologic tests by detecting
immunoglobulin antibodies within several weeks of
infection (in both humans and cats)
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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
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Congenital infections – detecting T. gondii DNA in
amniotic fluid using molecular methods such as PCR
Treatment for Humans
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Combinations of pyrimethamine with
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Trisulfapyrimidines or sulfadiazine
Folinic acid in the form of leucovorin calcium to protect
the bone marrow from the toxic effects of pyrimethamine
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Combination of sulfamethoxazole and trimethoprim
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For pregnant women
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First four months – spiramycin
After four months – sulfadizain/pyrimethamine and folinic
acid
Congenitally infected babies are treated with sulfonamide
and pyrimethamine
Treatment for Cats
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Antibiotic called Clindamycin
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Pyrimethamine with sulfadizine
Control Measures
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Do not allow cats to hunt or roam
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Do not eat raw or undercooked meat, and don’t drink
water from the environment
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Keep your cat from using the garden or children’s play
area (i.e. sandbox) as a litter box
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Remove feces from litter box daily, and wash hands
after
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Pregnant women should not clean the litter box
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Control rodent populations and other potential
intermediates