Syndromic management of sexually transmitted infections in the Brazilian Amazon: A 10-year retrospective study

Background The syndromic approach is a widely applied strategy for managing sexually transmitted infections (STIs) in settings where laboratory diagnostics are limited. This study aimed to describe temporal patterns in syndromic STI diagnoses and identify factors independently associated with these diagnoses over a period of 10 years at a reference center in the state of Amazonas, Brazilian Amazon. Methodology/Principal findings A retrospective review was conducted using medical records from patients attending a reference center for STI care in Amazonas, Brazil, from 2014 to 2023. Sociodemographic, clinical, and behavioral data were analyzed. The syndromic classification followed World Health Organization guidelines and included vaginal discharge, cervical discharge, urethral discharge, genital ulcers, and genital warts. A total of 32,485 medical records were reviewed, with 14,931 (46.0%) syndromic diagnoses identified. The most frequent syndromes were genital warts (41.0%), urethral discharge (31.5%), genital ulcer (21.3%), cervical discharge (3.8%), and vaginal discharge (2.3%). In multivariate analysis, factors independently associated with receiving a syndromic diagnosis were age ≥ 30 years (OR = 1.16; 95% CI: 1.05–1.20), male sex (OR = 2.31; 95% CI: 1.75–2.45), single marital status (OR = 1.82; 95% CI: 1.43–2.21), irregular condom use (OR = 3.21; 95% CI: 2.46–3.60), and having two or more casual partners (OR = 3.42; 95% CI: 2.94–3.90). Conclusions/Significance Despite inherent limitations, the syndromic approach remains an essential strategy for STI control in resource-constrained contexts such as the Amazon. It facilitates prompt treatment and broadens access to care where laboratory confirmation is unavailable. Integrating syndromic and etiological approaches is vital to improve diagnostic accuracy, optimize antimicrobial use, and strengthen public health responses to STIs in the region.