Epidemiological profile of polioviruses in Mali from 2020 to 2024

Abstract

Introduction: In Mali, polio cases are detected through surveillance of acute flaccid paralysis (AFP) and environmental surveillance. This study identified confirmed cases of polio, described their characteristics, and determined the trend. Material and methods: A descriptive cross-sectional study was conducted between January 1 and July 31, 2025. We extracted data recorded from January 1, 2020, to December 31, 2024, from the PFA and environmental surveillance databases of the Ministry of Health and Social Development. The data were analyzed using Epi Info 7. Results: A total of 70 cases (2.2%) from AFP surveillance and 10 (2.9%) from environmental surveillance were confirmed as circulating type 2 poliovirus (cPVDV2c). For PVDV2c cases from AFP surveillance, the median age was 2 years (IQR [1 year; 3 years]), while 64% were male. In terms of vaccination status, 61.4% of cases were vaccinated. For PVDV2c cases from environmental surveillance, non-polio enterovirus rates were 65% in 2020; 46% in 2021; 42% in 2022; 30% in 2023; and 59% in 2024. The promptness of sample delivery to the reference laboratory was 50% in 2020; 40% in 2021; 88% in 2022; 75% in 2023; and 87% in 2024. Conclusion: The majority of PVDV2c detected in Mali from 2020 to 2024 were human cases, particularly boys under the age of 5. We recommend strengthening routine vaccination and surveillance.