Estimations of the incidences of toxoplasma infections among pregnant women from different areas in Norway.

2342 male military recruits from different parts of Norway were selected for serological screening with the dye test or the IgG-indirect fluorescent antibody test. The highest frequency of toxoplasma antibodies was observed in the south-western areas (27%), whereas the prevalence was found to be as low as 2% in the northermost areas of the country. On the basis of the prevalence values obtained in the different counties, the incidence rates for acquired infections in the pregnant population have been calculated. The annual incidence in Norway was estimated to be 4 0/00 and the incidence of congenital toxoplasmosis would be maximally 2 0/00 (or about 110 cases/year).