Mpox among Linked Heterosexual Casual Partners in Bayelsa, Nigeria

This correspondence describes epidemiologic and clinical features of 16 mpox cases,11 confirmed, 5 probable among heterosexual casual partners treated in Bayelsa, Nigeria, during the 2022 outbreak. All patients reported condomless receptive or insertive vaginal sex with mpox-positive partners within a month of symptom onset. Median incubation period was 5 days, serial interval 8 days, and recovery time 20 days. All had genital rashes, most with febrile prodromes, and none had anorectal lesions. Rash localization reflected sexual exposure sites, contrasting with presentations in men who have sex with men. Transmission chains included secondary and tertiary cases, involving partners with symptoms, presymptomatic or healed genital lesions. The findings support sexual transmission of MPXV in heterosexual networks and underscore risks of misdiagnosis due to atypical presentation. Larger studies and genomic surveillance are recommended to clarify transmission dynamics and inform public health efforts.

This correspondence describes epidemiologic and clinical features of 16 mpox cases,11 confirmed, 5 probable among heterosexual casual partners treated in Bayelsa, Nigeria, during the 2022 outbreak. All patients reported condomless receptive or insertive vaginal sex with mpox-positive partners within a month of symptom onset. Median incubation period was 5 days, serial interval 8 days, and recovery time 20 days. All had genital rashes, most with febrile prodromes, and none had anorectal lesions. Rash localization reflected sexual exposure sites, contrasting with presentations in men who have sex with men. Transmission chains included secondary and tertiary cases, involving partners with symptoms, presymptomatic or healed genital lesions. The findings support sexual transmission of MPXV in heterosexual networks and underscore risks of misdiagnosis due to atypical presentation. Larger studies and genomic surveillance are recommended to clarify transmission dynamics and inform public health efforts.