Temporal, seasonal, and spatial patterns of Mpox in the DRC, 2002–2022: longitudinal surveillance study

Abstract

Introduction: Mpox has shown increasing incidence and geographic spread since its first identification in the Democratic Republic of the\001 Congo (DRC) in 1970.

Methodology: We analyzed weekly mpox surveillance data reported from 2002-2022 in the DRC. Temporal trends were assessed using time-series decomposition to separate secular trends, seasonal patterns, and residual variation. Change-point analysis identified distinct transmission phases. Spatial trends were analyzed through thematic mapping of incidence rates across Health Zones.\001

Results: Between 2002 and 2022, a total of 55,072 suspected mpox cases and 1,297 deaths were reported, corresponding to an overall case fatality rate (CFR) of 2.4% and a mean CFR of 2.15% (95% CI: 1.8–2.5). Incidence increased progressively, with marked rises after 2010 and further intensification after 2015. Recurrent seasonal peaks were observed at the beginning of the year (February) and during mid-year (May–July). Change-point analysis identified four distinct transmission phases, during which annualized incidence increased from 0.78 to 2.67 cases per 100,000 population, alongside a steady geographic expansion from 56 to 159 health zones. By the most recent phase (2018–2022), approximately 30% of health zones nationwide had reported mpox cases. While CFRs declined during the intermediate phases, they increased again in recent years, reaching 2.63% in Phase IV.

Conclusions: Mpox remains persistently endemic in the DRC, with progressive geographic expansion. These findings underscore the need for sustained surveillance, strengthened community engagement, and targeted prevention strategies embedded within a broader One Health framework to address zoonotic and ecological drivers of transmission.