In May 2023, the World Health Organization issued a statement declaring the end of mpox (formerly monkeypox) a public health emergency. Just over a year later, the agency was forced to backtrack, and a much more serious epidemic is occurring across much of sub-Saharan Africa.
According to statistics, more than 15,000 cases of mpox and 461 deaths have been reported on the African continent since January, with the disease spreading from countries such as the Democratic Republic of Congo (DRC), where it has long been endemic, to 13 African countries previously unaffected by the disease, such as Rwanda, Kenya, Burundi and Uganda.
To scientists like Boguma Titanzi, an associate professor of infectious diseases at Emory University who studies M.P.O.X. outbreaks, this new, more deadly outbreak represents the fallout from a previous failure by global health watchdogs to act sufficiently.
The first alarm bells were raised about the spread of Mpox in the summer of 2022. The virus, which had always been present mainly in parts of West and Central Africa, suddenly spread around the world. From early 2022 to December 2023, there were 92,783 confirmed cases of Mpox in 116 countries, and 171 deaths.
Despite these numbers, awareness of it as a public health threat quickly faded. “Ninety-five percent of the cases in the 2022 outbreak were among men who have sex with men, and they reported exposure through sexual or close contact with another infected person,” says Titanji. “It was a very concentrated outbreak, so we were able to prioritize vaccination in that network.”
Northern Hemisphere countries have struggled successfully to contain outbreaks within their borders. Meanwhile, Titanji says, African countries that have been battling a steady rise in mpox cases for the past 40 years have quickly fallen down the priority list as they ramped up virus surveillance, allowing potentially more troubling variants to emerge undetected.
Mpox exists in two main subtypes, Clade 1 and Clade 2. Clade 1 is thought to be up to 10 times more deadly, especially in children under 5, pregnant women, and people with weakened or developing immune systems. This is the strain of the virus behind this new outbreak, and why infectious disease scientists are so alarmed. (A separate outbreak spreading among HIV-infected people in South Africa is thought to be linked to Clade 2.)
“The pandemic in 2022 was at stage 2, with a mortality rate of less than 1%,” said Jean Nachega, a Congolese infectious disease physician and assistant professor of medicine at the University of Pittsburgh. “Now we’re talking about strains that could have a mortality rate of up to 10%.”
Previous outbreaks have primarily affected gay communities, but data suggest the new strain is spreading much more widely, probably first through sexual networks and then to family members. Last month, Nachega and others published a paper in the journal Nature Medicine showing how an mpox outbreak began in the small mining town of Kamituga in eastern Democratic Republic of Congo among sex workers, then spread to nearby Rwanda, Uganda, and Burundi when infected individuals returned home to visit family.