Introduction Current trends in Sexually Transmitted Infection (STI) epidemics indicate a shift in their profiles, with accelerated growth in more vulnerable populations such as people living on the streets. The objective of this study was to estimate the prevalence of STIs and to evaluate the risk behaviours for these infections among homeless persons in Goiânia, Central Brazil.

Methods This cross-sectional study was conducted between August 2014 and June 2015. Eligible participants were homeless persons sheltered in public housing of Goiânia, in Central Brazil, aged 18 years or older. All were interviewed on demographics, history of street living, sexual behaviour, and substance use. Blood samples were submitted to rapid tests for HIV, syphilis, and hepatitis B, and a positive result on any one or more of these tests indicated presence of an STI. Univariate and multivariable Poisson regressions were done to identify correlates of ISTs. This study was approved by the Research Ethics Committee of the Federal University of Goiás.

Results Among 353 eligible homeless persons, the majority were male (81.3%), single (59.8%), with a mean age between 18 and 40 years old (63.5%), who declared themselves to be mixed race (60.9%) and had 9 years of education or fewer (78.5%). The prevalence of STI was 25.5% (90/353, 95% CI: 21.2%–30.3%), for HIV 4,0% (14/353), syphilis 22,1% (78/353) and hepatitis B 0,8% (3/353). It was verified that age (RP: 1.02, 95% CI: 1.00–1.03), female sex (RP: 1.72, 95% CI: 1.18–2.50), sex with members of the same sex (RP: 1.62, 95% CI: 1.11–2.37) and sex with drug users (RP: 1.81, 95% CI: 1.18–2.77) were statistically associated with STI positivity (p≤0.01).

Conclusion The results of this study show that life on the streets is a significant risk factor for exposure to STIs, and requires proactive health outreach. Street outreach offices are one effective public health strategy to access the homeless population and can act in the prevention and control of STIs.