History of sexually transmitted infections among mpox cases in the 2022 outbreak in Spain

The aim was to describe the history of sexually transmitted infections (STIs) among adult mpox men cases and to analyse sociodemographic and epidemiological characteristics according to the presence or absence of any STI diagnosed 1 or 6 months previous to mpox diagnosis during the 2022 outbreak in Spain.

A cross-sectional study was conducted as part of a multicentre study in seven Spanish regions. Mpox patients were enrolled by the epidemiological surveillance services from June 2022 to January 2023. We conducted descriptive and bivariate analyses to compare sociodemographic, epidemiological and clinical characteristics of mpox according to the presence of a previous STI diagnosis. Associations were assessed using logistic regression to estimate crude odds ratio (OR) and adjusted odds ratio (aOR) with 95% confidence intervals (95% CI).

A total of 1202 mpox individuals were included (96.4% were men); 36% (417/1159) of males had previous STI during the 6 months previous to mpox diagnosis. Chemsex practice (aOR 1.66, 95% CI: 1.11-2.47), practicing sex in leisure places (aOR 1.68, 95% CI: 1.12-2.51), having HIV diagnosis (aOR 1.91, 95% CI: 1.32-2.77) and using pre-exposure prophylaxis (PrEP) (aOR 4.43, 95% CI: 3.05-6.45) were more frequent among males with a history of STI in the 6 months previous to mpox diagnosis. No statistical differences were found in mpox clinical manifestations and hospitalization according to STI history.

Overlapping risk behaviours and shared transmission routes contributed to the high prevalence of STI history in mpox cases. Epidemiological characteristics studied in mpox cases with previous STI may help identify target populations and planning an integrated prevention strategy.