Toxoplasma gondii is a coccidian parasite. Man can be infected with Toxoplasma gondii from various sources: ingestion of infected meat, especially mutton and pork, or ingestion of soil contaminated by oocyst from domestic and feral cats. Transmission by organ transplant, transfusion or activation of quiescent infections is also documented. Congenital Toxoplasmosis is a disease with an extraordinarily wide range of manifestations; so wide in fact, that it must be considered in the differential diagnosis of nearly all types of obscure illness occurring during infancy.
In acquired Toxoplasmosis, levels of IgM antibody are generally detectable very early in the infection and peak within one or two months after clinical onset. They typically remain detectable for only a few weeks, but can persist for as long as 2 years.
The detection of IgM specific antibody can be of major importance in the diagnosis of congenital Toxoplasmosis in the neonate, because IgM class antibodies do not cross the placental barrier. It is also helpful in differentiating recently acquired (acute) toxoplasmosis from chronic infection.
The sensitivity, specificity, and reproducibility of enzyme-linked immunoassays is comparable to other serological tests for antibody.