Twenty-five years of HIV: lessons for low prevalence scenarios

Use of routine HIV testing data for early detection of emerging HIV epidemics in high-risk subpopulations: A concept demonstration study

Introduction

HIV epidemics in hard-to-reach high-risk subpopulations are often discovered years after epidemic emergence in settings with poor surveillance infrastructure. Using hypothesis-generation modeling, we aimed to investigate and demonstrate the concept of using routine HIV testing data to identify and characterize hidden epidemics in high-risk subpopulations. We also compared this approach to surveillance based on AIDS case notifications.

Methods

A deterministic mathematical model was developed to simulate an emerging HIV epidemic in a high-risk subpopulation. A stochastic Monte Carlo simulation was implemented on the total population to simulate the sampling process of generating routine HIV testing data. Epidemiological measures were estimated on the simulated epidemic and on the generated testing sample. Sensitivity analyses were conducted on the results.

Results

In the simulated epidemic, HIV prevalence saturated at 32% in the high-risk subpopulation and at 0.33% in the total population. The epidemic started its emerging-epidemic phase 28 years after infection introduction, and saturated 67 years after infection introduction. In the simulated HIV testing sample, a significant time trend in prevalence was identified, and the generated metrics of epidemic emergence and saturation were similar to those of the simulated epidemic. The epidemic was identified 4.0 (95% CI 3.4–4.6) years after epidemic emergence using routine HIV testing, but 29.7 (95% CI 15.8–52.1) years after emergence using AIDS case notifications. In the sensitivity analyses, none of the sampling biases affected the conclusion of an emerging epidemic, but some affected the estimated epidemic growth rate.

Conclusions

Routine HIV testing data provides a tool to identify and characterize hidden and emerging epidemics in high-risk subpopulations. This approach can be specially useful in resource-limited settings, and can be applied alone, or along with other complementary data, to provide a meaningful characterization of emerging but hidden epidemics.

HIV/STI RISK-TAKING SEXUAL BEHAVIOURS AND RISK PERCEPTION AMONG MALE UNIVERSITY STUDENTS IN TEHRAN: IMPLICATIONS FOR HIV PREVENTION AMONG YOUTH

Recent evidence indicates a rising trend in premarital sexual activity among young people in Iran. However, little is known about the extent to which young people's sexual behaviours expose them to HIV and STI risks. This study aimed to assess HIV/STI-related sexual risk-taking behaviours (correlates and determinants) and HIV/STI risk perception among male university students in Tehran. A representative sample of male university students (N=1322) studying in government and private Tehran universities completed an anonymous questionnaire survey in 2013-14. Respondents were selected using two-stage stratified cluster sampling. About 35% of respondents had ever had premarital sex (n=462). The majority (about 85%) of the sexually experienced students reported having multiple sexual partners in their lifetime. More than half (54%) reported inconsistent condom use over the previous month. Despite this exposure to HIV/STI risk, the respondents had a very low level of HIV/STI risk perception. Only 6.5% were highly concerned about contracting HIV over the previous year, and an even lower percentage (3.4%) were concerned about contracting STIs in the near future. Early sexual debut (<18 years), studying in a private university, ever watching pornography and work experience were found to be significant predictors of having multiple sexual partners. Younger age at sexual debut, having one lifetime sexual partner and poor HIV knowledge were significant predictors of inconsistent condom use over the preceding month. HIV prevention programmes among Iranian youth need to focus on the postponement of first sex and enhancement of HIV/STI knowledge in the light of increasing access of young people to pornography.

Bridging the social and the biomedical: engaging the social and political sciences in HIV research

This supplement to the Journal of the International AIDS Society focuses on the engagement of the social and political sciences within HIV research and, in particular, maintaining a productive relationship between social and biomedical perspectives on HIV. It responds to a number of concerns raised primarily by social scientists, but also recognized as important by biomedical and public health researchers. These concerns include how best to understand the impact of medical technologies (such as HIV treatments, HIV testing, viral load testing, male circumcision, microbicides, and pre-and post-exposure prophylaxis) on sexual cultures, drug practices, relationships and social networks in different cultural, economic and political contexts. The supplement is also concerned with how we might examine the relationship between HIV prevention and treatment, understand the social and political mobilization required to tackle HIV, and sustain the range of disciplinary approaches needed to inform and guide responses to the global pandemic. The six articles included in the supplement demonstrate the value of fostering high quality social and political research to inform, guide and challenge our collaborative responses to HIV/AIDS.