Review on Toxoplasmosis and Its Zoonotic Importance

Abstract

The genus toxoplasma has a single species, Toxoplasma gondii, which is an intestinal coccidian of cats. The life cycle includes a facultative systemic phase, which is an important cause of abortion in sheep and may also cause a zoonosis. Natural infection has been described in almost every mammalian order, including over 19 species of captive and free-ranging ungulates. All felids, but the domestic cat is the most important final host for the parasite and any other mammals including man, or birds are the intermediate hosts. Fortunately, the pathological changes are relatively uncommon and most toxoplasma infections in animals and man are light and consequently asymptomatic. Human infections are particularly serious if they occur during pregnancy and may result in abortion or congenitally acquired disorders, which primarily affect the central nervous system. In Ethiopia, the prevalence of immunoglobulin G antibodies to Toxoplasma gondii has been determined by enzyme linked immunosorbent assay and the highest antibody titers were found in children, young and adults. Human immuno deficiency virus-1 frequently leads to resurgence of toxoplasmosis. The most important role of toxoplasmosis in ruminants is its association with abortion and perinatal mortality. In cats and dogs the most frequent signs of toxoplasmosis are associated with infection of central nervous system and the visual, respiratory and gastrointestinal systems.