Using Modeling to Explore the Degree to Which a Microbicide's Sexually Transmitted Infection Efficacy May Contribute to the HIV Effectiveness Measured in Phase 3 Microbicide Trials
- 1 August 2008
- journal article
- research article
- Published by Wolters Kluwer Health in JAIDS Journal of Acquired Immune Deficiency Syndromes
- Vol. 48 (4) , 460-467
- https://doi.org/10.1097/qai.0b013e31817aebd6
Abstract
Several microbicide candidates show activity against pathogens that cause sexually transmitted infections (STIs). This may increase a microbicide's impact on HIV in phase 3 trials. Modeling is used to estimate the degree to which a microbicide's STI efficacy contributes to the HIV effectiveness of a phase 3 microbicide trial. An expression is derived and coupled with an STI model to estimate how much a microbicide's STI efficacy contributes to a trial's HIV effectiveness. The STI model estimates the decrease in STI prevalence that may occur in the trial's active gel arm for microbicides of different STI efficacy. Projections are produced for different STI cofactors and epidemiological settings. The model projects that if a microbicide is active against curable STIs with a combined prevalence of >or=10% among trial participants and the reduction in HIV incidence is 50% in some cases) if the per exposure multiplicative STI cofactor is 2.5 or greater. However, if the STI prevalence is 50%, then the trial's HIV effectiveness will be mainly due to its direct HIV efficacy. In high STI settings, phase 3 trials documenting a moderate impact on HIV incidence may partially result from a gel's activity against curable STI. Care should be taken generalizing these trial results to other settings. This is less important for trials documenting large reductions in HIV incidence.Keywords
This publication has 12 references indexed in Scilit:
- Microbicide drug candidates to prevent HIV infectionThe Lancet, 2007
- The role of sexually transmitted infections in male circumcision effectiveness against HIV – insights from clinical trial simulationEmerging Themes in Epidemiology, 2006
- Are Targeted HIV Prevention Activities Cost-Effective in High Prevalence Settings? Results From a Sexually Transmitted Infection Treatment Project for Sex Workers in Johannesburg, South AfricaSexually Transmitted Diseases, 2006
- Randomized, Controlled Intervention Trial of Male Circumcision for Reduction of HIV Infection Risk: The ANRS 1265 TrialPLoS Medicine, 2005
- Monthly Antibiotic Chemoprophylaxis and Incidence of Sexually Transmitted Infections and HIV-1 Infection in Kenyan Sex WorkersJAMA, 2004
- The Role of Disease-Specific Infectivity and Number of Disease Exposures on Long-Term Effectiveness of the Latex CondomSexually Transmitted Diseases, 2002
- A Systematic Review of the Epidemiologic Interactions Between Classic Sexually Transmitted Diseases and HIVSexually Transmitted Diseases, 2001
- Control of sexually transmitted diseases for AIDS prevention in Uganda: a randomised community trialThe Lancet, 1999
- Impact of improved treatment of sexually transmitted diseases on HIV infection in rural Tanzania: randomised controlled trialThe Lancet, 1995
- AN ESTIMATE OF THE RISK OF MEN ACQUIRING GONORRHEA BY SEXUAL CONTACT WITH INFECTED FEMALES1American Journal of Epidemiology, 1970