To determine the prevalence of antibodies against Treponema pallidum and herpes simplex virus type 2 (HSV-2), and to identify the factors associated with these infections among migrants in transit in Chiapas, Mexico.
Cross-sectional study conducted during 2021–2022, in three migrant shelters in Chiapas, Mexico. Participants answered a questionnaire and provided a blood sample to detect antibodies against Treponema pallidum and HSV-2. The study calculated seroprevalence and assessed associated factors using Chi-square (χ2) tests and odds ratios.
A total of 462 migrants participated, with an average age of 31.2 years; 56.9% were women, and 41.1% came from Honduras. The seroprevalence of HSV-2 was 29.9%; for syphilis it was 4.5%, and it was higher in men (8.0%) than in women (1.9%). Among pregnant women, 15.4% had antibodies against syphilis. Notable variables associated with syphilis include being male, having a history of genital lesions, having same-sex partners, and seropositivity to HSV-2. Regarding HSV-2, factors associated with infection included being female, age, schooling, sleeping in the street, a history of HIV testing, early sexual debut, number of sexual partners, and syphilis.
A high prevalence of syphilis and HSV-2 was found among the migrant population evaluated. Syphilis is confirmed as a re-emerging infection, even in women. Migrants have vulnerabilities associated with sexual behavior, so prevention, diagnosis, and treatment measures should be focused on this population group.