How Many Sexual Partners of an Individual Need to Be Evaluated to Capture HIV/STI Risk Behavior in a Study?

Investigators conducting HIV studies ask participants multiple questions about sexual risk behaviors with their partners to ensure that they can describe the level of HIV risky sexual behavior. The assessment should be as short as possible because of the expense of collecting the data, the burden to the research subject, and ethical concerns. This study used data from the NIMH Collaborative HIV/STD Prevention Trial to answer the question about how many non-spousal/non live-in partners a research participant needs to be asked about to capture sufficient sexual risk behavior (not using a condom with a non-spousal/non live-in partner in the last 3 months). The data provided evidence that 95 % of the sexual risk behavior was captured by asking about two partners while 98 % was captured by three partners. As research funds become increasingly limited, it is important to design as parsimonious and robust a study as possible.

The utility of a composite biological endpoint in HIV/STI prevention trials.

A human immunodeficiency virus (HIV) as a biological endpoint in HIV prevention trials may not be feasible, so investigators have used surrogate biological outcomes. In a multisite trial, the epidemiology of STIs may be different across sites and preclude using one STI as the outcome. This study explored using a composite STI outcome to address that problem. The combined biological endpoint was the incidence of any of six new STIs (chlamydia, gonorrhea, trichomonas (women only), syphilis, herpes simplex virus type 2 infection and HIV) during a 24-month follow up period. We investigated how a composite STI outcome would perform compared to single and dual STI outcomes under various conditions. We simulated outcomes for four populations that represented a wide range of sex and age distributions, and STI prevalences. The simulations demonstrated that a combined biologic outcome was superior to single and dual STI outcomes in assessing intervention effects in 82 % of the cases. A composite biological outcome was effective in detecting intervention effects and might allow more investigations to incorporate multiple biological outcomes in the assessment of behavioral intervention trials for HIV prevention.

The incidence and correlates of symptomatic and asymptomatic Chlamydia trachomatis and Neisseria gonorrhoeae infections in selected populations in five countries.

BACKGROUND: Asymptomatic Chlamydia trachomatis (chlamydia) and Neisseria gonorrhoeae (gonorrhea) infections pose diagnostic and control problems in developing countries. METHODS: Participants in China, India, Peru, Russia, and Zimbabwe were screened for C. trachomatis and N. gonorrhoeae infections and symptoms. RESULTS: A total of 18,014 participants were evaluated at baseline, 15,054 at 12 months, and 14,243 at 24 months. The incidence of chlamydia in men was 2.0 per 100 person years both from baseline to 12 months and from 12 to 24 months, and in women, 4.6 from baseline to 12 months and 3.6 from 12 to 24 months; a range of 31.2% to 100% reported no symptoms across the 5 countries. The incidence of gonorrhea in men was 0.3 per 100 person years both from baseline to 12 months and from 12 to 24 months, and in women, 1.4 from baseline to 12 months and 1.1 from 12 to 24 months; a range of 66.7% to 100% reported no symptoms. Being female, aged 18 to 24 years, and having more than 1 partner were associated with both the infections. In addition, being divorced, separated, or widowed was associated with gonorrhea. Being male, having 6+ years of education, and reporting only 1 partner were associated with having no symptoms among those infected with chlamydia. No variables correlated with asymptomatic gonorrhea among those infected. CONCLUSION: A high prevalence and incidence of asymptomatic sexually transmitted infections was identified among men and women in a wide variety of settings. More effective programs are needed to identify and treat chlamydia and gonorrhea infections, especially among women, young adults, those with multiple partners, those repeatedly infected, and particularly those at risk without symptoms. The risk of transmission from persons with no symptoms requires further study.

High prevalence of forced sex among non-brothel based, wine shop centered sex workers in Chennai, India.

Sexual violence has been shown to increase women's risk of HIV infection. India is a country where the HIV epidemic is growing among women and intimate partner violence (IPV) is pervasive. This study examined prevalence of and factors associated with forced sex among female sex workers (FSWs) in Chennai, India. We conducted a probability survey among FSWs in 24 slum venues and identified predictive factors for recent forced sex using univariate and multivariable proportional odds models. Among 522 FSWs, 28% reported having forced sex with one partner and 35% with 2+ partners. In the final multivariable model, women who had a high number of partners who had a strong tendency to drink alcohol before sex were more likely to have experienced forced sex, and women who had both unprotected sex with a nonspousal partner and > 20 days of alcohol consumption in the last 30 days were more likely to have experienced forced sex. Discussion about family violence with larger social networks was independently associated with lower odds of forced sex among FSWs. HIV interventions for FSWs and their clients aimed at reducing alcohol consumption and encouraging condom use could be enhanced by violence prevention interventions to facilitate discourse about sexual violence.

Prevalence of Sexually Transmitted Diseases and Risk Behaviors from the NIMH Collaborative HIV/STD Prevention Trial.

This cross-sectional study describes the baseline prevalence and correlates of common bacterial and viral sexually transmitted diseases (STDs) and risk behaviors among individuals at high risk for HIV recruited in five low- and middle-income countries. Correlations of risk behaviors and demographic factors with prevalent STDs and the association of STDs with HIV prevalence are examined. Between 2,212 and 5,543 participants were recruited in each of five countries (China, India, Peru, Russia, and Zimbabwe). Standard protocols were used to collect behavioral risk information and biological samples for STD testing. Risk factors for HIV/STD prevalence were evaluated using logistic regression models. STD prevalence was significantly higher for women than men in all countries, and the most prevalent STD was Herpes simplex virus-type 2 (HSV-2). HIV prevalence was generally low (below 5%) except in Zimbabwe (30% among women, 11.7% among men). Prevalence of bacterial STDs was generally low (below 5% for gonorrhea and under 7% for syphilis in all sites), with the exception of syphilis among female sex workers in India. Behavioral and demographic risks for STDs varied widely across the five study sites. Common risks for STDs included female gender, increasing number of recent sex partners, and in some sites, older age, particularly for chronic STDs (i.e., HSV-2 and HIV). Prevalence of HIV was not associated with STDs except in Zimbabwe, which showed a modest correlation between HIV and HSV-2 prevalence (Pearson coefficient = .55). These findings underscore the heterogeneity of global STD and HIV epidemics and suggest that local, focused interventions are needed to achieve significant declines in these infections.