In a sample consisting of both men who have sex with men and transgender women, 12% of respondents tested positive for HIV, and those who did not know that they were infected had an elevated likelihood of having engaged in some risky behaviors, according to a cross-sectional study conducted in Bogotá, Colombia.¹ Six in 10 respondents who tested positive learned of their status through participation in the study, and these individuals were more likely than those who already knew their positive serostatus to have had transactional sex (49% vs. 17%) and to have recently used drugs (41% vs. 23%). Compared with seronegative participants, HIV-positive respondents were more likely to have experienced forced relocation or suffered violence.

Although HIV testing is freely available in Colombia, which has the second-highest HIV prevalence in Latin America, use of the service is uncommon, likely because of entrenched stigma and aggression toward homosexual and HIV-positive individuals. To assess the level of HIV infection in Bogotá among men who have sex with men and among transgender women, and to examine whether their characteristics and behavior vary according to their knowledge of their HIV status, researchers surveyed eligible residents over a 10-month period in 2011.

The study used respondent-driven sampling: Four men who had sex with men recruited other participants, who in turn did the same; several additional such waves of referral resulted in a final sample of 938 men who have sex with men and 58 transgender women. Participants were eligible if they were aged 18–49, had been born male and had had sex with a man in the prior six months. All respondents were paid for their participation and for any recruits they brought into the study. They completed a questionnaire via audio computer-assisted self-interviews that asked about their social and demographic characteristics, HIV testing history, HIV status (positive, negative, unknown), history of other STIs, insurance coverage and risk behaviors, including drug and alcohol use, unprotected anal sex and transactional sex. Respondents also indicated whether they had ever been forced to move from their place of residence, and estimated, on a scale from 0 (never) to 3 (many times), how often they had been the victim of violence. Participants were given an oral HIV test and were counseled before and afterward. Those with positive test results underwent confirmatory tests and, if appropriate, received a referral for medical care. A higher proportion of HIV-positive participants than of their HIV-negative counterparts invited others of the same status to join the study.

Two-thirds of respondents were aged 24 or younger (64%), most were of low socioeconomic status (82%), and about half had attended university (47%), had a main partner (49%) and had ever taken an HIV test (54%). Two-thirds had either private (30%) or government-subsidized (33%) insurance, while the remainder had no coverage, were covered only for emergency care or did not know their insurance status (37%). Eleven percent of respondents had at some point been forced to relocate, and 28% had exchanged sex for money, goods or services. Some 12% tested positive for HIV. Sixty percent of those with HIV—or 7% of all respondents—did not know that they were infected prior to the study; of the 40% who already knew that they were seropositive, almost all were taking antiretroviral medication.

In bivariate analyses comparing respondents’ characteristics, behaviors and experiences by awareness of HIV status, those who were unaware that they had HIV were more likely than uninfected respondents and those who knew that they were HIV-positive to have ever had transactional sex (49% vs. 17–27%)and to have used drugs (41% vs. 23–26%) or engaged in binge drinking (28% vs. 9–15%) in the last three months. However, a slightly different pattern emerged for unprotected anal sex: Prevalence was highest among respondents who were unaware that they were HIV-positive (66%) and those who were HIV-negative (62%), and lowest among participants who knew that they had HIV (38%), a finding consistent, the authors note, with evidence that "knowledge of positive serostatus tends to lead to decreases in risky sexual behavior." Compared with HIV-negative respondents, those in the two seropositive groups were more likely to have been forced to move (18–26% vs. 10%) and had higher mean scores on the experience of violence scale (0.31–0.33 vs. 0.22). Finally, two-thirds of participants who knew they were HIV-positive had had an STI, compared with half of those who were unaware and one-third of those who were seronegative.

The researchers acknowledge that the sample included too few transgender women to analyze as a separate group and that young respondents were overrepresented (perhaps because they were more motivated by the study’s financial incentives and more engaged with their community than were older men). These limitations notwithstanding, the HIV prevalence findings corroborate those of a previous survey of the same population, and provide further evidence that HIV-positive individuals who are unaware of their status may be more likely than their peers to engage in certain risky behaviors.

Moreover, the researchers note, Colombians generally continue to struggle with poverty, internal displacement and violence, which may have prevented respondents from obtaining HIV testing and care. They emphasize that, in addition to targeted attacks and stigma, these social issues must be taken into account when addressing "the widespread problem of undiagnosed infection among Colombian [men who have sex with men] and transgender women."—S. Ramashwar

REFERENCE

1. Zea MC et al., HIV prevalence and awareness of positive serostatus among men who have sex with men and transgender women in Bogotá, Colombia, American Journal of Public Health, 2015, 105(8):1588–1595.