An epidemic of a new variant of clade I mpox, called clade 1b, began in Central Africa at least as early as September 2023. As of September 2024, more than 29,000 cases have been reported, with over 800 fatalities, nearly all in the Democratic Republic of the Congo. According to the European CDC: "The size of these outbreaks could be larger than reported due to under-ascertainment and under-reporting."