Toxoplasma gondii – Emphasis on diagnosis

Abstract

Toxoplasmosis is a disease caused by the protozoan Toxoplasma gondii. In Brazil,
its prevalence range (10%-80%) varies depending on the studied area. Humans
may acquire the infection by ingestion of contaminated food with cysts or oocysts,
blood transfusion, organs transplant and congenital transmission. In the latter, the
parasite crosses the placental barrier and infects the fetus causing severe sequelae.
The serological diagnosis of toxoplasmosis is based on the detection of antibodies
anti-T. gondii. Contrary to the efficiency of serology in pregnant women (in 89.5%
of cases), the confirmation of infection in the fetus and/or newborn is difficult due
to the presence of residual antibodies from the mother which produces doubtful
and/or inconclusive results. This fact enhances the need of parasitological methods,
especially molecular biology techniques that may allow the follow-up of pregnant
women and the validation of the treatment. Prevention of congenital toxoplasmosis
is of main importance to infection control, avoiding the severe sequelae that may
occur in the fetus and the newborn. This review describes the etiological agent
of toxoplasmosis, T. gondii, its epidemiology, clinical manifestations, diagnosis,
prevention and treatment.