In May 2023, the World Health Organization issued a statement declaring the end of monkeypox (MPOX) as a public health emergency. Just over a year later, the agency was forced to backtrack, as a much more serious epidemic brews across much of sub-Saharan Africa.
Statistics show that since January, more than 15,000 cases of mpox and 461 deaths have been reported on the African continent, spreading from countries such as the Democratic Republic of the Congo (DRC), where mpox has long been endemic, to 13 other African nations – countries such as Rwanda, Kenya, Burundi and Uganda, where the disease had never before made an impact.
In the eyes of scientists like Boghuma Titanji, an associate professor of infectious diseases at Emory University who studies mpox outbreaks, this new, deadlier outbreak represents the consequence of global health watchdogs not doing enough last time.
It was in the summer of 2022 that the spread of mpox first set off alarm bells. Suddenly, a virus that had always been predominantly contained to parts of West and Central Africa was spreading across the globe. Between early 2022 and December 2023, there were 92,783 confirmed cases of mpox in 116 countries, resulting in 171 deaths.
Despite these numbers, its perception as a public health threat quickly faded. “Ninety-five percent of cases during the 2022 outbreak were among men who have sex with men and who reported exposure through sexual or close contact with another infected person,” Titanji says. “It was a very localized outbreak, which allowed for vaccinations to be prioritized within that network.”
Countries in the global north successfully scrambled to contain the outbreak within their own borders. Meanwhile, Titanji says, ramping up viral surveillance among African nations that had been battling a steady rise in mpox cases over the past four decades soon fell to the back of the priority list, allowing a potentially more problematic variant to emerge undetected.
Mpox exists in two main subtypes, clade 1 and clade 2. Together, clade 1 is thought to be up to ten times more lethal, particularly among population groups with weakened or developing immune systems, such as children under five, pregnant women, and immunocompromised people. That’s the viral strain behind this new outbreak, and it’s why infectious disease scientists are so alarmed. (A separate outbreak spreading in South Africa among people living with HIV is thought to be linked to clade 2.)
“The 2022 global outbreak was clade 2 and mortality was less than 1 percent,” says Jean Nachega, a Congolese infectious disease physician and associate professor of medicine at the University of Pittsburgh. “We are now talking about a strain that may be up to 100% resistant to the virus.” 10 percent mortality.”
While the previous outbreak predominantly affected gay populations, data indicate that the new strain is also being transmitted much more widely, perhaps initially through sexual networks and then moving to family members. Last month, Nachega and others published a paper In the diary Nature Medicine shows how an outbreak of mpox began in the small mining town of Kamituga in eastern Democratic Republic of Congo via sex workers, before spreading to nearby Rwanda, Uganda and Burundi as infected people returned home to visit their families.