First imported cases of MPXV Clade Ib from Goma, Democratic Republic of the Congo

Abstract

Background: The ongoing mpox outbreaks in the Democratic Republic of the Congo (DRC) resulted in >71,000 suspected cases from 01 January 2024 to 02 February 2025. Clade Ib mpox virus (MPXV) emergence has heightened public health concern due to observed sustained human-human transmission and spread to multiple non-endemic East African countries. Clade Ib outbreaks have been marked by epidemiologic deviations from classic Clade Ia zoonotic transmission—Clade Ib instead has been observed among adult populations and transmission via sexual contact. With the continued expansion of Clade Ib across the region, containment and mitigation measures may need to be adapted to best fit this novel MPXV clade. Methods: Case investigation and epidemiological assessment data as well as whole viral geonome sequencing was analyzed from confirmed mpox infected individuals in the Goma region. Case demographics and clinical presentation data was also assessed from suspected mpox cases in the region. Results: We report the first introduction of Clade Ib into North Kivu province through close contact transmission. We also report limited human-human Clade Ib transmission chains among children <15 years in the Mudja internal displaced persons camp. We further present evidence of APOBEC3 mutations and genomic links between these North Kivu cases with the larger ongoing Clade Ib outbreak in Kamituga, South Kivu. Conclusions: Given the expansion of regional mpox outbreaks and populations considered at-risk, these findings underscore how mpox case investigations and community messaging should include considerations for non-sexual human-human transmission of Clade Ib that includes children <15 years.