Q. What is the parasite that causes toxoplasmosis? How is the disease transmitted and what are its typical manifestations?

The Toxoplasmosis is caused by the protozoan Toxoplasma gondii, a sporozoan.

The Toxoplasmosis is a disease transmitted by cats, which are thea definitive hosts of the parasite. The Cats eliminate toxoplasma oocysts in feces; the oocysts are extremely resistant and stay viable for months in the environment. The Human beings are infected when ingesting food or water contaminated by oocysts or when making contact with contaminated objects. Humans able to also become infected by eating meat of animals like pork, sheep and cow, which can be intermediate hosts too. The Vertical transmission, from mother to offspring, may also take place.

In the toxoplasmosis the cystic form of the parasite invades tissues of the body, including the retina and the brain. The infestation is potentially fatal and in congenital toxoplasmosis the child may present mental retardation and blindness. The disease is mainly severe when occurring as an opportunistic disease in AIDS patients.