Congenital toxoplasmosis: past, present and future

Abstract

Toxoplasmosis is the first infection of the TORCH complex (Toxoplasmosis, Rubella, Cytomegalovirus and Herpes simplex) and one of the most important congenital diseases. Consideration is too often limited to the cases of very severe toxoplasmosis with numerous and spectacular symptoms at birth, such as hydrocephalus, neurological disorders and ocular involvement, which lead to major handicaps. However, the frequency of attenuated, asymptomatic or poorly symptomatic congenital toxoplasmosis is often disregarded. The asymptomatic infections may give rise to very late reactivation, which sometimes occurs in puberty or even adulthood. The reactivation of unrecognised congenital toxoplasmosis is sometimes accompanied with neurological disorders, and is a common cause of retinochoroiditis. The retinochoroiditis can be very disabling and the majority cases of retinochoroiditis in young adults are thought to be secondary to untreated congenital toxoplasmosis. This is the most severe medical and socio-economical consequence of congenital toxoplasmosis and is the reason behind the pre- and neonatal screening programmes.