The host cell eventually bursts and releases tachyzoites which invade other cells. It is these latent infections that can provide problems in humans. The prepatent period in the cat - time from ingestion of infective material to oocyst excretion in the faeces, varies with the stage ingested. Cooks or butchers that handle raw meat are particularly at risk. Man and other animals can be infected by the congenital route and acute infection in children can cause severe clinical symptoms.
Children can become infected playing near cat litter trays etc.
The congenital condition can occur when a pregnant woman acquires toxoplasmosis for the first time, usually if infected at start of gestation period. Incidence in France and Austria of congential infection is 3-4 per 1000 births. In adults toxoplasmosis is almost symptomless but may result in fever and swelling. It is almost probable that illness in a result of a reactivated latent infection. That is, cysts with bradyzoites are present, but do no further damage in the immune competent person.