Overstating social networks' ability to diagnose new cases of HIV

A comparison of the effectiveness of respondent-driven and venue-based sampling for identifying undiagnosed HIV infection among cisgender men who have sex with men and transgender women in Tijuana, Mexico

BACKGROUND

Efforts to increase HIV testing, diagnosis and care are critical to curbing HIV epidemics among cisgender men who have sex with men (MSM) and transgender women (TW) in low- and middle-income countries (LMIC). We compared the effectiveness of respondent-driven sampling (RDS) and venue-based sampling (VBS) for identifying previously undiagnosed HIV infection among MSM and TW in Tijuana, Mexico.

METHODS

Between March 2015 and December 2018, we conducted RDS within the social networks of MSM and TW and VBS at venues frequented by MSM and TW to socialize and meet sexual partners. Those reached by RDS/VBS who reported at least 18 years of age, anal sex with MSM or TW, and no previous HIV diagnosis were eligible for HIV testing.

RESULTS

Of those screened following recruitment via RDS (N = 1232; 98.6% MSM; 1.3% TW), 60.8% (749/1232) were eligible for HIV testing and 97.5% (730/749) were tested for HIV infection, which led to the identification of 36 newly diagnosed HIV infections (4.9%). Of those screened following recruitment via VBS (N = 2560; 95.2% MSM; 4.6% TW), 56.5% (1446/2560) were eligible for HIV testing and 92.8% (1342/1446) were tested for HIV infection, which led to the identification of 82 newly diagnosed HIV infections (6.1%). The proportion of new HIV diagnoses did not differ by recruitment method (ratio = 0.81, 95% confidence interval: 0.55 to 1.18). Compared to those recruited via RDS, those tested following recruitment via VBS were younger, more likely to identify as gay, and more likely to identify as TW. Compared to those recruited via VBS, those newly diagnosed with HIV infection following recruitment via RDS reported higher levels of internalized stigma and were more likely to report injection drug use and a history of deportation from the United States.

CONCLUSIONS

Despite RDS and VBS being equally effective for identifying undiagnosed HIV infection, each recruitment method reached different subgroups of MSM and TW in Tijuana. Our findings suggest that there may be benefits to using both RDS and VBS to increase the identification of previously undiagnosed HIV infection and ultimately support HIV care engagement among MSM and TW in Mexico and other similar LMIC.

Implementing a Standardized Social Networks Testing Strategy in a Low HIV Prevalence Jurisdiction

Alternative HIV testing strategies are needed to engage individuals not reached by traditional clinical or non-clinical testing programs. A social networks recruitment strategy, in which people at risk for or living with HIV are enlisted and trained by community-based agencies to recruit individuals from their social, sexual, or drug-using networks for HIV testing, demonstrates higher positivity rates compared to other non-clinical recruitment strategies in some jurisdictions. During 2013–2015, a social networks testing protocol was implemented in Wisconsin to standardize an existing social networks testing program. Six community-based, non-clinical agencies with multiple sites throughout the state implemented the protocol over the 2-year period. Both quantitative and qualitative data were collected. The new positivity rate (0.49%) through social networks testing did not differ from that of traditional counseling, testing, and referral recruitment methods (0.48%). Although social networks testing did not yield a higher new positivity rate compared to other testing strategies, it proved to be successful at reaching high risk individuals who may not otherwise engage in HIV testing.

Multiple strategies to identify HIV-positive black men who have sex with men and transgender women in New York City: a cross-sectional analysis of recruitment results

INTRODUCTION

Black men who have sex with men and transgender women are at high risk for HIV infection, but are more likely to be unaware of their infection or not in care for diagnosed HIV compared to other races. Respondent driven sampling has been advanced as a method to reach stigmatized and hidden populations for HIV testing. We compared strategies to recruit black, substance-using men who have sex with men and transgender women to identify newly diagnosed HIV infection, or those previously diagnosed but not in care.

METHODS

The STAR (Seek, Test, and Retain) study (ClinicalTrials.gov NCT01790360) used several recruitment strategies to identify black, substance-using men who have sex with men and transgender women with undiagnosed HIV infection or with previously diagnosed HIV infection but who were not in HIV care. Respondent-driven sampling, community-based recruitment and online advertising were used to recruit participants. Incentivized peer referral was integrated into all recruitment strategies. Participants completed interviewer-administered questionnaires and HIV testing. Demographic and HIV risk-related characteristics and recruitment strategy were summarized and stratified by HIV status. Associations were tested using Pearson's chi-squared, Fisher's exact, and Wilcoxon rank sum tests. Factors associated with HIV-positive diagnosis at p < 0.1 were included in a multivariable logistic regression model.

RESULTS

From July 2012 through October 2015, the study enrolled 1929 participants; 96.3% men who have sex with men and 3.7% transgender women. Behavioural risk factors included recent condomless anal sex (55.6%) and recent substance use during sex (73.1%). HIV prevalence was 8.7%. In multivariable analysis, significant associations with HIV infection included being transgender; non-Hispanic black; gay/homosexual orientation; not homeless; and less likely to have insufficient income for necessities. Among recruitment strategies, respondent driven sampling was least effective in identifying HIV-positive participants.

CONCLUSIONS

Integrating multiple recruitment strategies yielded a large sample of black men who have sex with men and transgender women at substantial risk for HIV. Respondent-driven sampling was less effective than other strategies at identifying men who have sex with men and transgender women with HIV.

Factors associated with recent HIV testing among men who have sex with men in New York City

Understanding factors associated with recent HIV testing among men who have sex with men (MSM) is important for designing interventions to increase testing rates and link cases to care. A cross-sectional study of MSM was conducted in NYC in 2011 using venue-based sampling. Associations between HIV testing in the past 12 months and relevant variables were examined through the estimation of prevalence ratios (PR) and 95 % confidence intervals (CI). Of 448 participants, 107 (23.9 %) had not been tested in the past 12 months. Factors independently associated with not testing in the previous 12 months were: lack of a visit to a healthcare provider in the past 12 months (aPR: 2.5; 95 % CI: 1.9, 3.2); age ≥30 (adjusted PR: 1.9; 95 % CI: 1.4, 2.7); not having completed a bachelor's degree (aPR: 1.6; 95 % CI: 1.0, 2.4); and non-gay sexual identity (aPR: 1.4; 95 % CI: 1.0, 1.8); such MSM may be less aware of the need for frequent HIV testing.

Evaluation of the relative effectiveness of three HIV testing strategies targeting African American men who have sex with men (MSM) in New York City

BACKGROUND

African American men who have sex with men (MSM) are disproportionately affected by HIV and constitute more than half of all HIV-infected MSM in the USA.

PURPOSE

Data from the New York City location of a multi-site study were used to evaluate the effectiveness of three HIV testing strategies for detecting previously undiagnosed, 18 to 64-year-old African American MSM. Effectiveness was defined as the identification of seropositive individuals.

METHODS

Using a quasi-experimental design (N = 558), we examined HIV-positive test results for men tested via alternative venue testing, the social networks strategy, and partner counseling and referral services, as well as behavioral risk factors for 509 men tested through alternative venue testing and the social networks strategy.

RESULTS

Detection rates of HIV-positives were: alternative venue testing-6.3%, the social networks strategy-19.3%, and partner services-14.3%. The odds for detection of HIV-positive MSM were 3.6 times greater for the social networks strategy and 2.5 times greater for partner services than alternative venue testing. Men tested through alternative venue testing were younger and more likely to be gay-identified than men tested through the social networks strategy. Men who tested through the social networks strategy reported more sexual risk behaviors than men tested through alternative venue testing.

CONCLUSIONS

Findings suggest differential effectiveness of testing strategies. Given differences in the individuals accessing testing across strategies, a multi-strategic testing approach may be needed to most fully identify undiagnosed HIV-positive African American MSM.