Prevalence of Toxoplasma gondii infection and incidence of toxoplasma encephalitis in non-haemophiliac HIV-1-infected adults in Taiwan

We assessed the seroprevalence of Toxoplasma gondii infection and incidence of toxoplasma encephalitis (TE) in 844 non-haemophiliac HIV-infected patients in Taiwan between June 1994 and April 2003. Approximately 70% (69.3%) of them had a baseline CD4+ lymphocyte count of 200 × 106/L or less, and more than 70% (73.9%) having initiated highly active antiretroviral therapy. The seroprevalence of T. gondii infection was 10.2%, which did not differ with sex, age, route of transmission, birth inside or outside of Taiwan, or CD4+ lymphocyte stratifications. After a median observation duration of 603 days (range, 1–3264 days), 10 (1.2%) patients developed 11 episodes of TE after a median interval of 30 days (range, 1–941 days) between enrolment and diagnosis of TE, with an incidence of 0.59 per 100 person-years (PY) (95% confidence interval, 0.56–0.63 per 100 PY). We concluded that the incidence of TE of HIV-infected patients in Taiwan was lower than that reported in western countries because of a lower seroprevalence of T. gondii infection and use of antimicrobial prophylaxis and antiretroviral therapy, although most of the patients were at the late stage of HIV infection.