A common sexually transmitted bacterial infection more than doubles the risk of HIV infection in African women, reports a study in the March issue of AIDS. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.
The study finds that women with the "emerging" sexually transmitted disease (STD) Mycoplasma genitalium are more likely to acquire HIV infection. "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," comments lead author Sue Napierala Mavedzenge, PhD, MPH, of the Women's Global Health Imperative, RTI International, San Francisco and the Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London..
Infection with M. genitalium May Double Women's HIV Risk
Data from a larger study of HIV acquisition among young women in Zimbabwe and Uganda were used to assess the effects of M. genitalium on HIV risk. First discovered in 1980, M. genitalium is a bacterial STD that causes inflammatory conditions of the reproductive tract (urethritis, cervicitis, and pelvic inflammatory disease). The infection—which may be present for years without causing any symptoms—can be eliminated with appropriate antibiotics.
In the study, 190 women who became infected with HIV during follow-up were matched to women of similar age and risk who did not acquire HIV. Both groups were tested for the presence of M. genitalium, which was evaluated as a risk factor for HIV infection.
In initial samples—when all women were HIV-free—infection with M. genitalium was present in about 15 percent of women who later developed HIV versus 6.5 percent in women who remained HIV-free. Mycoplasma genitalium was more frequent than other bacterial STDs, such as gonorrhea or chlamydia.
After adjustment for other factors, women who initially had M. genitalium were more than twice as likely to become infected with HIV. Certain other STDs were also risk factors for HIV.
The researchers estimated that about nine percent of all HIV infections occurring in the study were attributable to M. genitalium. However, other factors were more strongly associated with HIV risk—especially the presence of herpes simplex virus-2 (the virus that causes genital herpes) and having a partner with HIV risk factors
"M. genitalium may be an important, modifiable risk factor for HIV-1 acquisition among women in Zimbabwe and Uganda," Dr Napierala Mavedzenge and coauthors write. The inflammation caused by this sexually transmitted infection may increase susceptibility to HIV infection. If so, then identifying and treating women infected with M. genitalium might help to reduce the risk of HIV. Because the infection can remain asymptomatic for a long time, screening for M. genitalium would be an important part of any such strategy.
The study provides "compelling" evidence that M. genitalium is involved in HIV acquisition, according to an accompanying editorial by Lisa E. Manhart, PhD, of the University of Washington, Seattle. However, she believes that screening and treatment for M. genitalium would be "an extremely difficult and costly undertaking, and more evidence demonstrating that this intervention significantly reduces HIV-1 incidence is needed before we consider the costs and benefits of implementing such a program." Dr Manhart adds, "Our HIV prevention resources should be focused on implementing those proven interventions that together will have the largest impact."