Background:

Transgender women worldwide have among the highest prevalence of HIV and the lowest access to prevention among groups at risk. However, few longitudinal studies have directly measured HIV incidence and identified predictors of HIV acquisition among transgender women.

Setting:

São Paulo, Latin America’s largest city.

Methods:

We conducted a longitudinal study among transgender women in São Paulo. Participants were recruited by a long-chain peer referral process from May 2017 to July 2019. Those age 18 years and older and HIV-negative at baseline were retested every 6 months up to 18 months. HIV incidence was calculated by dividing the number of seroconversions by the person-years (py) of follow-up; 95% confidence intervals (CI) were constructed assuming a Poisson distribution. Conditional maximum likelihood ratios assessed differences in HIV incidence by risk factors.

Results:

A racial/ethnically diverse sample of 545 transgender women were enrolled. In 485.5 py of follow-up, 13 seroconversions were observed yielding an incidence of 2.68 per 100 py (95% CI 1.43–4.58). HIV incidence was significantly higher among transgender women age 18 to 24 years (rate ratio 3.85, 95% CI 1.24–12.93) and among those who engaged in sex work in the preceding month (rate ratio 5.90, 95% CI 1.71–26.62).

Conclusion:

HIV transmission continues at a high rate among transgender women in Brazil. Factors such as young age, lower level of education, and limited employment opportunities may lead to dependence upon sex work which in turn increase HIV risk. Transgender-friendly prevention services, particularly programs delivering pre-exposure prophylaxis (PrEP) are urgently needed.