[Prevalence and public-health-aspects of toxoplasmosis].

Toxoplasmosis is one of the most common infectious diseases of man, which usually is not dangerous. Infection results from ingestion of cyst-containing meat products or by contact with oocyst-contaminated soil. Clinically relevant are (1) reactivation of latent infection in immunocompromised individuals or (2) primary infection during pregnancy with subsequent prenatal toxoplasmosis of the fetus. In Germany, law requires the prenatal infection to be reported to the Robert Koch-Institute. Since most Toxoplasma-infected children are asymptomatic at birth and later develop sequelae (retinochoroiditis) up to the age of 20 years, no valid epidemiological data are currently available for Germany. However, some studies indicate that seroprevalence correlates with age and that 26-54% of women of childbearing age have antibodies against Toxoplasma gondii; incidence rates during pregnancy have been calculated to be between 0.5 and 0.6%. Knowing the life cycle of Toxoplasma gondii will help to maintain preventive measures for seronegative pregnant women, children, and immunocompromised individuals.