RESUMO
ABSTRACT Objective: Although the development of prevention and treatment strategies for sexually transmitted infections in key groups has improved over the years, they still remain a challenge for health systems worldwide. In this context, the objective of this study is to assess the seroprevalence in the tested population, with an emphasis on key populations, aiming at identifying the participants' profile and consequently the development of testing strategies. Methods: The present study analyzed the seroprevalence of HIV, syphilis, and hepatitis B and C, and the epidemiological profiles of key and general populations tested at a reference public health facility for sexually transmitted infections testing and counseling in the city of Curitiba, Southern Brazil. A cross-sectional study was conducted to report data from 2010 to 2019. Results: A total of 67,448 samples were analyzed, 9,086 of these tested positive, 3,633 (56%) for HIV, 4,978 (77%) for syphilis, 340 (5%) for hepatitis C virus (HCV), and 135 (2%) for hepatitis B virus (HBV). Overall, most of the participants were men (79 to 87%), and predominantly white. For HIV and syphilis, the predominant age groups were 21-30 years old (48 and 50%), HBV 21-40 years old (31%), and HCV 41-60 years old (25%). A high seroprevalence of HIV and syphilis was observed in the investigated key populations with a higher frequency in sex workers, men who have sex with men, and transgender. Conclusion: The progressive increase in syphilis cases emphasizes the need for effective interventions to enhance adherence to the use of condoms, and to expand diagnosis and treatment for these key populations.