MAKING THE INVISIBLE VISIBLE: THE PORTRAIT OF SEXUALLY TRANSMITTED INFECTIONS AMONG HOMELESS POPULATIONS IN URBAN SÃO PAULO

Homelessness is a global human rights crisis requiring urgent attention. People experiencing homelessness (PEH) face vulnerabilities that expose them to disproportionate rates of sexually transmitted infections (STIs), although data on this reality remain scarce in Brazil. This study aimed to investigate the prevalence of STIs and associated factors among PEH in a medium-sized city in São Paulo State. An observational, cross-sectional, and prospective study including 140 PEH. Interviews and testing were conducted by the Street Clinic team. Statistical analysis used the chi-square trend test and t-test to compare two groups: with and without STIs (HIV, syphilis, hepatitis B or C), based on screening results. The mean age was 44 years (±12.1). Most participants self-identified as White (51%), had been homeless for over one year (72%), slept in shelters or houses (63%), had family ties (66%), and reported alcohol and/or drug use (71%). Regarding gender identity and sexual orientation, 75% were cisgender men, 19% cisgender women, and 3% transgender individuals; 91% heterosexual and 7% homo/bisexual. Illiteracy rate was 4%, and only 3% had higher education. About 12% had STIs: 4% HIV, 7% syphilis (treponemal test reactive), 3% hepatitis C, and 0% hepatitis B; 12.5% were coinfected. The STI-positive group was more likely to sleep on the streets (75% vs 33%, p = 0.001), identify as homosexual (25% vs 2%, p = 0.003), be transgender women (67% vs 33%, p = 0.033), have poor hygiene (63% vs 30%, p = 0.003), and use alcohol/drugs (100% vs 33%, p = 0.038). HIV and syphilis rates among PEH in this municipality were similar to those observed in large urban centers, whereas hepatitis B and C showed lower prevalence. These findings highlight the need for targeted interventions for LGBTQIA+ individuals experiencing homelessness, particularly transgender people, and for integrated and effective public health policies. This study aims to support more inclusive practices and strengthen citizenship among this often-invisible population.