Umer M. auteur aut IRD Chawansuntati K. auteur aut IRD Wipasa J. auteur aut IRD Jindaphun K. auteur aut IRD Kotemul K. auteur aut IRD Thant Y. M. auteur aut IRD Ngo-Giang-Huong Nicole auteur aut IRD Khamduang W. auteur aut IRD Hongjaisee S. auteur aut IRD text journalArticle eng text/pdf reformatted digital access Objectives: The 2022 global Mpox outbreak revealed major surveillance gaps, particularly among marginalized populations such as sex workers, whose role in undetected MPXV transmission remains poorly understood. This study aims to assess the seroprevalence of MPXV IgG antibodies and identify associated risk factors among sex workers in Chiang Mai, Thailand. Methods: In this cross-sectional study, 262 sex workers recruited from March to December 2022 were tested for prior MPXV exposure using an in-house indirect ELISA targeting the recombinant MPXV E8L antigen. Logistic regression models were used to identify demographic and behavioral factors associated with seropositivity. Results: MPXV IgG seroprevalence was 4.6% (12/262). Seropositivity was significantly higher among males than females (5.2% vs 4.0%, P = 0.011). In multivariable analysis, male gender (OR = 3.23, 95% CI: 1.109.47, P = 0.032), blood transfusion history (OR = 4.40, 95% CI: 1.35-14.25, P = 0.013) and sharing sharp objects with others (OR = 4.55, 95% CI: 1.12-18.48, P = 0.034) were significantly associated with Mpox seropositivity. Conclusion: Our findings reveal undetected MPXV circulation among Chiang Mai sex workers. The identified risk factors suggest overlapping parenteral and sexual vulnerabilities, emphasizing the need for integrated surveillance and targeted interventions. specialized Mpox virus Seroprevalence Sex workers In-house ELISA E8L antigen Thailand THAILANDE CHIANG MAI 052 050 160 108041 [9 p.] 2025 1201-9712 https://www.documentation.ird.fr/hor/fdi:010095313 10.1016/j.ijid.2025.108041 1201-9712 [F B010095313] https://www.documentation.ird.fr/hor/fdi:010095313 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2025-11/010095313.pdf IRD - Base Horizon / Pleins textes 2025-11-18 2025-11-18 fdi:010095313 fre