Download Toxoplasma gondii

Toxoplasma gondii
Christina 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/monstersinside-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
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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

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