Pregnant women, watch out for Toxoplasmosis parasite

Donya Betancourt, Pediatrician, Sanur, Bali, drdonya@hotmail.com

Cat owners beware. Up to 50 percent of the population is infected with Toxoplasmosis (toxo), an infection caused by the parasite Toxoplasma gondii. The toxo parasite is very common in cat feces, raw meat, raw vegetables, and the soil.

A protozoa is a single-celled animal. A parasite lives inside another living organism (the host) and takes all of its nutrients from the host. It can get into your body when you breathe in dust.

However, a healthy immune system will keep toxo from causing any disease. It does not seem to spread from person to person.

The most common illness caused by toxo is an infection of the brain (encephalitis). Toxo can also infect other parts of the body and can lead to coma and death.

The first signs of toxo include fever, confusion, headaches, disorientation, personality changes, tremors and seizures. It is usually diagnosed by testing for antibodies to Toxoplasma gondii.

Transmission may occur transplacentally, by ingestion of raw or undercooked meat containing tissue cysts, or by exposure to oocysts in soil contaminated with cat feces.

The infection occurs worldwide; those at risk of severe disease are the developing fetus and the immunocompromised.

Neonatal congenital toxoplasmosis is acquired transplancentally -- the mother presumably having acquired a primary infection during pregnancy. Abortion may ensue if infection occurs early in pregnancy. Infection later in pregnancy may result in miscarriage or stillbirth or in the birth of a living child.

Acquired toxoplasmosis is seldom symptomatic and is usually recognized serologically. However, symptomatic infection may present in any of four ways:

1) The more common mild lymphatic form may resemble infectious mononucleosis; fever, lymph node enlargement.

2) Chronic toxoplasmosis causes retinochoroiditis (infection of eye)

3) An acute, fulminating, disseminated infection.

4) In patients with AIDS, disseminated infection may occur.

The diagnosis is usually established serologically (blood test).

The parasite has been isolated during the acute phase of the disease by inoculating mice or tissue cultures with biopsy material from lymph nodes, muscle or other tissues.

The toxo antibody test shows whether you have been exposed to toxo. A positive test does not mean that you have toxo encephalitis. However, a negative antibody test means that you are not infected with toxo.

Brain scans by computerized tomography (CT scan) or magnetic resonance imaging (MRI scan) are also used to diagnose toxo. A CT scan for toxo can look very similar to scans for other opportunistic infections. An MRI scan is more sensitive and can make it easier to diagnose toxo.

Toxo is treated with a combination of pyrimethamine (Daraprimr) and sulfadiazine. Both drugs can cross the blood- brain barrier.

The best way to reduce your risk of infection is by not eating undercooked meat or fish. It is important to note that all types of red meat including beef, lamb, and pork when undercooked are sources for toxo.

If you own a cat it is important to take personal care when cleaning the cat box. Be sure to protect yourself by wearing gloves, covering your nose and mouth with a face mask and washing yourself thoroughly when you are finished cleaning the litter box.