MPXV suspected lesions were tested to other ulcerative pathogens in order to detect coinfections and establish an adequate diagnosis. Descriptive retrospective cross-sectional study taken at Centro Sanitario Sandoval, Madrid. Six hundred twenty ulcerative samples were tested by PCR for the main sexually transmitted pathogens including MPXV. A multivariate analysis was carried out to determine factors associated to MPXV. We detected 447 samples positive for MPXV, 38 of them were also positive for some of the other pathogens, mainly herpes simplex virus type 2 (HSV2). In the MPXV samples, 35.3% (61 of 173) of them were positive for ulcerative pathogens, mainly Treponema pallidum (TP). Men who have sex with men with genital or anorectal lesions were associated to MPXV infection. The clinical features may lead to diagnostic error, mainly with TP and HSV. MPXV should be considered as a sexually transmitted infection and should be included in the differential diagnosis of ulcerative STIs.
