Seroepidemiology of toxoplasma gondii infection in young school children in Islamabad.

Sera, from 270 school children (age 13 to 20 years) residing in suburbs of Islamabad, were investigated for the presence of toxoplasma gondii, IgG antibodies using the enzyme linked immunosorbent assay (ELISA). The overall prevalence was 17.4%. There was no significant difference between the two sexes. Since a positive test result for IgG antibodies at any level does not eliminate the possibility of a current infection, the toxoplasma IgG antibody positive children were further tested for the presence of toxoplasma IgM antibodies by the same technique. An acute infection was indicated in 12.7% (6/47) IgG positive children. This study shows that toxoplasmosis is prevalent in adolescence in Islamabad. The presence of cats and the degree of soil contact appeared compatible with hypothesis of transmission by oocysts. Poor sanitary habits and conditions and water shortage in schools may cause parasitic infection through contact between the children. An improvement in general hygienic conditions is important in reducing the rate of transmission by oocysts. Further studies are needed to assess the possible age of exposure to this parasite in the paediatric group.