Quantifying the Evolving Contribution of HIV Interventions and Key Populations to the HIV Epidemic in Yaoundé, Cameroon

BACKGROUND

Key populations (KP) including men who have sex with men (MSM), female sex workers (FSW), and their clients are disproportionately affected by HIV in Sub-Saharan Africa. We estimated the evolving impact of past interventions and contribution of unmet HIV prevention/treatment needs of key populations and lower-risk groups to HIV transmission.

SETTING

Yaoundé, Cameroon.

METHODS

We parametrized and fitted a deterministic HIV transmission model to Yaoundé-specific demographic, behavioral, HIV, and intervention coverage data in a Bayesian framework. We estimated the fraction of incident HIV infections averted by condoms and antiretroviral therapy (ART) and the fraction of all infections over 10-year periods directly and indirectly attributable to sex within and between each risk group.

RESULTS

Condom use and ART together may have averted 43% (95% uncertainty interval: 31-54) of incident infections over 1980-2018 and 72% (66-79) over 2009-2018. Most onward transmissions over 2009-2018 stemmed from sex between lower-risk individuals [47% (32-61)], clients [37% (23-51)], and MSM [35% (20-54)] with all their partners. The contribution of commercial sex decreased from 25% (8-49) over 1989-1998 to 8% (3-22) over 2009-2018, due to higher intervention coverage among FSW.

CONCLUSION

Condom use and recent ART scale-up mitigated the HIV epidemic in Yaoundé and changed the contribution of different partnerships to onward transmission over time. Findings highlight the importance of prioritizing HIV prevention and treatment for MSM and clients of FSW whose unmet needs now contribute most to onward transmission, while maintaining services that successfully reduced transmissions in the context of commercial sex.

Characterizing Cross-Culturally Relevant Metrics of Stigma Among Men Who Have Sex With Men Across 8 Sub-Saharan African Countries and the United States

Overcoming stigma affecting gay, bisexual, and other men who have sex with men (MSM) is a foundational element of an effective response to the human immunodeficiency virus (HIV) pandemic. Quantifying the impact of stigma mitigation interventions necessitates improved measurement of stigma for MSM around the world. In this study, we explored the underlying factor structure and psychometric properties of 13 sexual behavior stigma items among 10,396 MSM across 8 sub-Saharan African countries and the United States using cross-sectional data collected between 2012 and 2016. Exploratory factor analyses were used to examine the number and composition of underlying stigma factors. A 3-factor model was found to be an adequate fit in all countries (root mean square error of approximation = 0.02-0.05; comparative fit index/Tucker-Lewis index = 0.97-1.00/0.94-1.00; standardized root mean square residual = 0.04-0.08), consisting of "stigma from family and friends," "anticipated health-care stigma," and "general social stigma," with internal consistency estimates across countries of α = 0.36-0.80, α = 0.72-0.93, and α = 0.51-0.79, respectively. The 3-factor model of sexual behavior stigma cut across social contexts among MSM in the 9 countries. These findings indicate commonalities in sexual behavior stigma affecting MSM across sub-Saharan Africa and the United States, which can facilitate efforts to track progress on global stigma mitigation interventions.