Sero-molecular evaluation of Toxoplasma gondii infection among HIV-positive patients

Toxoplasmosis is one of the most common comorbidities in HIV-positive patients with CD4+ T lymphocytes below 200 cells/μl. Early diagnosis and treatment of toxoplasmosis reduces the mortality rate in HIV-positive people. The aim of this study was to estimate the seroprevalence of Toxoplasma gondii infection in HIV-positive patients in northwest Iran using serological and molecular methods.

This prospective cross-sectional study included 124 HIV-positive outpatients and was conducted from January to May 2016. Anti-T. gondii IgM and IgG antibodies were detected from sera samples by chemiluminescence, while buffy coat samples were analyzed by RT-PCR for DNA detection. Patients' socioepidemiological data were collected.

Using chemiluminescence, 47/124 samples (37.9%) were positive for anti-Toxoplasma IgG antibodies, 2/124 samples (1.62%) were positive for IgM antibodies while 2/124 samples (1.62%) contained both IgM and IgG. There were no IgM-positive or IgG-negative patients. RT-PCR revealed four (3.22%) positive samples. On the basis of the results, a statistically significant relationship was found between anti-Toxoplasma IgG antibody seropositivity and residence (p=0.012).

The study showed a relatively low seroprevalence of anti-T. gondii IgG and IgM antibodies in HIV-positive patients in northwest Iran, while the prevalence was much higher in other regions of Iran. However, regular screening for T. gondii antibodies and early initiation of therapy are very important to decrease the mortality rate in HIV-positive patients.