Human Congenital Toxoplasmosis

Notwithstanding, the severity of the sequels and the frequency of occurrence, congenital toxoplasmosis in humans continues to be a neglected disease in several countries, including Brazil. This is partly because a large proportion of infected children are asymptomatic at birth, and consequently are not diagnosed and treated during the first year of life, while most develop ocular and neuro–psycho–motor sequels in early adulthood. The disparity of several management protocols for acute toxoplasmosis has resulted in extreme difficulty for the physicians to make decisions, resulting in many patients being subjected to unnecessary therapies and invasive procedures or are not treated adequately. Another great difficulty lies with the diagnosis, since most pregnant women are asymptomatic when infected, while diagnosis is based on laboratory results, whose interpretation is dependent on several factors, including screening and confirmatory tests and the gestational age when blood sample was taken. Another difficulty is related with the post–natal diagnosis, because in many neonates, it is not possible to detect specific IgM antibodies, and the presence of IgG does not confirm an infection, since these can be passively transferred from the mother to the infant. Faced with this dilemma and based on the work of our group with patients, communities, health services, this team of specialists have accumulated widespread knowledge for the elaboration and implementation of the “Health surveillance program of gestational and congenital toxoplasmosis in Londrina, Paraná, Southern Brazil”. This successful program has served as the basis for this chapter.

Keywords: Clinical aspects, Epidemiology, Maternal screening, Molecular diagnosis, Neonatal screening, Ocular toxoplasmosis, Prevention, Risk factors, Surveillance program, Toxoplasma gondii, Transmission, Treatment.