The presence of other STDs increases the likelihood of both transmitting and acquiring HIV.
Increased likelihood of acquiring HIV. Women who are infected with other STDs have an increased number of HIV target cells (e.g., CD4+ cells) present in cervical secretions. Researchers believe that having a larger number of these cells increases a woman's likelihood of acquiring HIV infection if she is exposed to HIV. The genital ulcers caused by some bacterial and viral STDs are an efficient portal of entry for HIV.
Increased ability to transmit HIV infection to others. Studies have shown that when HIV-infected individuals also are infected with other STDs, they are more likely to shed HIV in both ulcerative and inflammatory genital secretions, and they also are more likely to shed HIV in greater amounts compared to people infected with HIV alone. Studies conducted in Africa demonstrate that individuals who are infected with both HIV and other STDs (e.g., gonorrhea, chlamydia, genital ulcers) were more than twice as likely to have HIV genetic material detectable in their genital secretions than were those who were infected with only HIV.
When STDs are detected and treated, HIV transmission is substantially reduced.
STD treatment reduces how much and how often HIV is shed. Studies from three African countries have shown that STD treatment of individuals who are coinfected with HIV and another STD decreases both the amount and how often the individual sheds the virus in genital secretions.
STD treatment reduces the spread of HIV infection in communities. A landmark community-level randomized trial in a rural area of Tanzania demonstrated a 42 percent decrease in new heterosexually transmitted HIV infections in communities with improved treatment of symptomatic STDs as compared to communities with minimal STD services.
In the private sector, access to STD services does not necessarily equate with quality. In one state with a strong health care infrastructure and where HMO enrollees have more annual preventive care visits than the national average, only an estimated 21 percent of sexually active teenaged women are screened for STDs.
In addition, most people are unaware of the connection between HIV and other STDs. In the recent Kaiser Family Foundation Survey on Public Knowledge and Attitudes about STDs other than HIV, 56 percent of the respondents did not know that STDs make a person more vulnerable to becoming infected with HIV. Furthermore, the high percentage of asymptomatic STDs in women decreases the likelihood that an infected woman will seek care.
Strong STD treatment and control is one of the few well-documented biomedical tools that clearly works to help prevent heterosexually transmitted HIV infection. It is an important component of model comprehensive HIV prevention programs, particularly for young women.
As part of an overall strategy, comprehensive HIV prevention programs should develop linkages with STD diagnostic and treatment services to incorporate (1) community-based efforts to improve STD care-seeking behavior, (2) high-quality on-site STD detection and treatment services at a variety of settings for HIV-infected persons, other persons at risk for HIV or other STDs, and their partners, (3) improved STD treatment for sex partners of infected persons, and (4) expanded STD surveillance systems. HIV Prevention Community Planning Groups have an important role in strengthening these linkages.
Grosskurth H, et al. Impact of improved treatment of sexually transmitted diseases on HIV infection in rural Tanzania: randomised controlled trial. Lancet. 1995;346:530-536
Institute of Medicine. The Hidden Epidemic: Confronting Sexually Transmitted Diseases. 1996. Washington, DC: National Academy Press
St. Louis ME, Wasserheit JN, Gayle HD. Editorial: Janus considers the HIV pandemic -- harnessing recent advances to enhance AIDS prevention. AJPH 1997;87:10-12