Types & Causes
Toxoplasmosis infections in people fall into three basic patterns:
- Congenital toxoplasmosis, in which the child becomes infected before birth.
- Toxoplasmosis in an otherwise healthy child.
- Toxoplasmosis in a child with a weak immune system.
Cats are the definitive host of the parasite. Over 80-90% of primary infections produce no symptoms. The incubation period for symptoms is 1 to 2 weeks.
There are many ways by which Toxoplasma can be transmitted to humans:
- When the mother becomes infected with Toxoplasma during pregnancy the parasite is transmitted directly from the pregnant mother to her unborn child.
- Consumption and handling of undercooked or raw meat from infected animals.
- Ingestion of food or water or inhalation of dust contaminated with the eggs of Toxoplasma organisms (called Oocysts).
- Drinking unpasteurized milk.
- Working in gardens or playing in sandboxes that contain cat feces.
- Eating uncooked, unwashed fruits or vegetables that have been contaminated by manure
A collection of fluid (eg. like water) in a closed sac. Cyst can appear anywhere in the body including brain, lungs, liver, kidneys or bones.
Pigs, sheep, goats, and poultry are sources of meat commonly infected with Toxoplasma. Of all the infected animals tested, only cats are the perfect hosts for the production of the infectious and resistant Toxoplasma oocysts. The oocyst, released from the intestine of cats in their feces, is very hardy and can survive sleet, freezing, and even several months of extreme heat and dehydration. Moreover, oocysts can be carried long distances by wind and water.
Congenital toxoplasmosis is caused by infection with Toxoplasma gondii in a pregnant woman. 50% of such infections are transmitted to the fetus. Signs of congenital infection may be present at birth or develop over the first few months of life.
Toxoplasma infection does not normally spread from person to person but in rare instances toxoplasmosis can contaminate blood transfusions and organs donated for transplantation.