Visualisation of the protozoa in body tissues or isolation in animals. Note High levels of antibody titres may persist for years without active disease. Intermediate hosts that carry an infective stage include sheep, goats, rodents, swine, cattle, chicken and birds. Mode of Transmission Children may become infected by ingesting oocysts from dirt, sandpits and playgrounds in which cats have defecated. Infections may be acquired by eating raw or undercooked infected meat containing tissue cysts.
Transplacental infection occurs when a woman has a primary infection.
Incubation Period Uncertain, but probably ranges from several days to months. Period of Communicability Oocysts spread by cats may remain infective in water or moist soil for about a year. Cysts in the flesh of infected animals remains infective as long as the meat is uncooked. Susceptibility and Resistance Susceptibility to infection is general, but immunity is readily acquired and most infections are asymptomatic. The duration and degree of immunity is assumed to be long lasting or permanent.