Association of sexually transmitted diseases and infection with the human immunodeficiency virus: Biological cofactors and markers of behavioural interventions

Sexually transmitted diseases (STDs) interact uniquely with HIV infection, regardless of the form of sexual transmission of HIV. Both STDs and HIV infection are behaviorally and biologically intertwined with one another. This concept is called epidemiologic synergy since they facilitate the sexual transmission of one another. Assuming that one accepts this concept, innovative and comprehensive STD control programs along with community and individual-based prevention programs should provide a more effective HIV control program by reducing the efficiency of HIV transmission in high-risk individuals. Public health workers can assess the effectiveness of these programs by monitoring incident STDs in high-risk groups. Other benefits of using incident STDs as markers for HIV prevention include: biological validation of self-reported behavioral change, possible association between self-reports of behavioral change and recall or social desirability bias, representation of a major target population for HIV programs by people at risk for STDs, and sensitive, specific, and noninvasive STD-assays. Disadvantages of using incident STDs as markers for HIV prevention are: incident STDs are unreliable for detecting deficiencies in one individual component (i.e., condom use), they can be used only in areas with a high STD prevalence and high transmission probability, STD diagnostic assays are not 100% sensitive and specific, and untreated/undetected STDs at enrollment may be mislabeled as incident STDs at follow-up. Questions remain about the validity of self-reported condom use and the use of STDs to evaluate individual intervention measures, e.g., condom use within a short period of time. Monitoring of HIV incidence would be ideal, but it may take too long. Valid measures of condom use and other risk behavior are needed to determine risk status and changes in risk status over time. Thus, further research is needed to develop more accurate measures.