HIV/AIDS

Prevention and Treatment of Sexually Transmitted Infections

Introduction

Sexually transmitted infections (STI) have been shown to be important cofactors in the transmission and acquisition of HIV infection. For example, in Rakai, Uganda, research has shown an emergence of genital herpes simplex virus (HSV) in areas with mature HIV epidemics (i.e., areas with a high prevalence of HIV). Investigators found a nearly fivefold association of HSV with HIV-1 acquisition. Having uncovered this synergistic effect between STIs and HIV, researchers now hypothesize that control of one may have beneficial effects on the control of the other.

Effective STI control requires both targeted and more generalized strategies. Targeted interventions that reduce transmission in groups such as sex workers, migrant workers, and truck drivers have led to rapid STI control in several areas, particularly in Thailand, the South African mining areas, and Nairobi. Meanwhile, research has shown that improved access to quality STI services for the general population alone can have a measurable impact on HIV transmission, especially in populations with growing HIV epidemics. These examples provide evidence that control of STIs in the context of HIV transmission may represent an effective HIV prevention strategy.

Therefore, one of NIAID’s goals is to design interventions that are more effective at controlling STIs as a strategy to reduce the incidence of HIV.

Background

Following are several key points regarding the interaction of STIs and HIV transmission:

• Targeted interventions that improve STI treatment and increase condom use in high-risk networks may have the greatest impact on sexual transmission of curable STIs, HSV, and HIV.
• Specific intensive STI interventions, such as STI treatment to high-frequency transmitters, can bring about rapid reductions in STI prevalence.
• Continuous access to improved STI services may have the greatest impact on HIV transmission.
• Treatment of asymptomatic STIs is critical to reducing overall STI prevalence.
• STI treatment is critical in populations with early or growing HIV epidemics; the contribution of STIs to the spread of HIV may decline in more mature epidemics.
• Genital ulcers, such as those associated with HSV-2, are potent cofactors in both HIV transmission and acquisition.
• Lack of male circumcision is correlated with higher risks of HIV acquisition.

Research Activities

NIAID is supporting a number of research studies that examine prevention of STIs as a strategy to reduce HIV acquisition and transmission.

• HIV Prevention Trials Network (HPTN)
  Co-sponsored by NIAID, the National Institute of Child Health and Human Development, the National Institute of Mental Health, and the National Institute on Drug Abuse, the HPTN is a worldwide collaborative clinical trials network that develops and tests the safety and efficacy of primarily non-vaccine interventions designed to prevent the transmission of HIV.
  For more information about HPTN research, including ongoing clinical studies to prevent and treat STIs as a way of preventing HIV infection.
• CRISP database
  This online database can be used to search for ongoing research supported by NIAID. (Keywords: Prevention, STI, male circumcision, or search for a specific STI such as HSV-2.)

• AIDSinfo
  This government Web site has information on HIV/AIDS-related health topics, treatment and prevention guidelines, information on drugs and vaccines, and a database of all federally funded HIV/AIDS clinical trials.

NIAID Contact

Sheryl Zwerski, R.N., M.S.N., C.R.N.P.
Division of AIDS, Prevention Sciences Branch
E-mail: szwerski@niaid.nih.gov

back to top