Skin-to-skin household transmission of mpox from parental wrist lesion to child's gluteal region.

Mpox clade IIb is transmitted predominantly through intimate contact within sexual networks, yet non-sexual household transmission can also occur. We report laboratory-confirmed mpox in a Belgian man in his 40s presenting with an orofacial and a wrist lesion and his preschool daughter who developed a solitary gluteal lesion 4 days after direct contact with the father's wrist lesion. The anatomical concordance between the child's gluteal and the father's wrist lesion suggested direct cutaneous transmission during routine caregiving activities. Comprehensive investigation included biological samples (saliva, urine, exhaled breath condensate), environmental samples (indoor air, high-touch surfaces) and companion animal specimens. Testing revealed extensive environmental MPXV DNA contamination. No replication-competent virus was recovered from any specimen, consistent with low viral loads in later stages of infection and in the environment of patients with mpox. Both patients achieved complete resolution without antiviral therapy or complications.