A multidimensional clustering approach identified seven distinct patient profiles attending a Parisian sexual health center, demonstrating that both key populations and lower-risk populations visit such centers, with high HIV/STI positivity rates found in two very different clusters: socially disadvantaged patients without health insurance and men who have sex with men.
The study population attending a free Parisian sexual health center for HIV/STI screening was predominantly young, with a median age of 26 years.
Seven distinct clusters of patients were identified using a mixed approach of a priori classification and agglomerative hierarchical clustering based on multiple correspondence analysis.
Two clusters had high HIV/STI positivity rates of 15-19% but with very different sociodemographic and behavioral profiles.
Two clusters had HIV/STI positivity rates corresponding to the overall study population rate (10-11%) but exhibited notable risk behaviors or knowledge gaps.
HIV knowledge gaps were identified as a concern across patient groups, particularly among those engaged in transactional sex.
The study found that a key-population-only approach to STI prevention is insufficient because lower-risk populations with risky behaviors also attend sexual health centers.
Social disadvantage and lack of health insurance were associated with high HIV/STI positivity, identifying a non-behavioral risk cluster.
This research suggests that people who visit a free sexual health clinic in Paris for HIV and sexually transmitted infection (STI) testing are not a homogeneous group. By analyzing data from over 5,000 patients collected between 2017 and 2020, researchers identified seven distinct types of visitors. Two groups had notably high rates of HIV/STI diagnoses (15-19%): one group consisted largely of men who have sex with men, and another consisted of socially disadvantaged people without health insurance — two very different profiles that both ended up with similarly elevated infection rates. The study also found two additional groups whose infection rates matched the overall clinic average (around 10-11%) but who still engaged in concerning behaviors or had significant gaps in HIV knowledge. One of these groups included people who engage in transactional sex, all of whom showed poor knowledge about HIV despite being at risk. Another group reported frequent unprotected sex, drug use, cannabis use, and weekly heavy drinking. This research suggests that risk is shaped not just by who someone is (their identity or group membership), but also by their behaviors, social circumstances, and what they know about HIV. The practical implication of this research is that sexual health clinics serve a diverse range of people with very different needs, and a one-size-fits-all approach — or one that only focuses on traditionally recognized 'high-risk' groups — may miss important opportunities for prevention. The authors suggest that clinic visits should be used to deliver tailored messages and interventions for all patients, and that improving HIV knowledge should be a priority for every visitor, regardless of their apparent risk level.
Husson M, de La Rochebrochard E, Morand E, Segouin C, Troude P. (2025). Who attends a free sexual health center in Paris for HIV/STI screening? an observational study.. BMC public health. https://doi.org/10.1186/s12889-025-21881-7