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

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.