Seroprevalence of Toxoplasma gondii Infection in HIV-positive and HIV-negative subjects in Gauteng, South Africa

Abstract

Toxoplasmosis is an infection of warm-blooded vertebrates caused by one of the most common parasites of humans, Toxoplasma gondii. T. gondii is an obligate intracellular protozoan parasite with a worldwide distribution and a varying prevalence between different continents and countries, and even within the same country. There is little known about T. gondii prevalence in Africa. In South Africa, there is limited information about the disease and detailed recent demographic data of groups at risk are missing. The seroprevalences of T. gondii antibodies in samples of selected populations, namely HIV-positive male and female subjects, and HIV-negative pregnant women in the Gauteng province, were therefore investigated and found to be 9.8% (95% confdence interval: 7.1%-13.4%) and 12.8 % (CI: 8.9%-15.8%), respectively. A more general population sample (but biased towards pregnant women) showed a 6.4% (CI: 4.5%-9%) seroprevalence. These results show that T. gondii infection is present in South Africa, but its prevalence is much lower than previously reported in this region. While the burden of disease has been reduced in recent times, a low prevalence means that more previously unexposed people are at risk of acquiring an acute infection, which may cause congenital disease in pregnant women, or which, in reactivation form, may ultimately be life-threatening in HIV/AIDS patients.