STD Bacteria Leads to Potential HIV Infection

African women who are infected with a common sexually transmitted bacterial infection are two times more likely to acquire Human immunodeficiency virus (HIV) infection.

Mycoplasma genitalium is an emerging sexually transmitted infection (STI) associated with reproductive tract syndromes in men causing urethritis, and in women, it is associated with cervicitis and pelvic inflammatory disease.

In a multi-institute study, conducted by the Research Triangle Institute (RTI International; San Francisco, CA, USA) HIV-negative women from Zimbabwe and Uganda were tested once every 12 weeks for a median of 22 months. Blood was collected for HIV diagnosis using several different enzyme-linked immunosorbent assays (ELISA). M. genitalium testing was performed on samples at the HIV detection visit and the last HIV-negative visit for cases, and equivalent visits in follow-up time for controls. Presence of M. genitalium DNA was assessed by in-house polymerase chain reaction (PCR)-ELISA, using the archived cervical swab samples, which had been stored at -20 °C.

The scientists compared 190 women who became infected with HIV during follow-up to women of a comparable age and risk who were not infected with HIV. The team examined women in both groups for the presence of M. genitalium, which was assessed as a risk factor for HIV infection. They found that in initial samples when all participants were HIV free, approximately 15% of women who later developed HIV were infected with M. genitalium compared with 6.5% in women who did not develop the disease. Furthermore, the team found that M. genitalium was more prevalent that other bacterial sexually transmitted diseases caused by Neisseria gonorrhoeae and Chlamydia trachomatis.

According to the team, M. genitalium was responsible for approximately 9% of all HIV infections occurring in the study. Other factors, such as having a partner with HIV risk factors, or the presence of herpes simplex virus 2, which causes genital herpes, were more strongly linked to HIV risk. Sue Napierala Mavedzenge, PhD, a lead researcher of the study, said, "Further research will be required to confirm a causal relationship and to identify risk factors for M. genitalium infection in African populations. If findings from this research are confirmed, M. genitalium screening and treatment among women at high risk for HIV-1 infection may be warranted as part of an HIV-1 prevention strategy.” The study was published March 13, 2012 in the journal AIDS.

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Research Triangle Institute