In a remote Congolese town, a medical mystery led to the discovery of alarming changes in the mpox virus and, eventually, to a global health emergency.
Yves Mujula, who works for Congoβs National Institute of Biomedical Research, and Serge Siklui, who works with the aid agency Alima, carry a cooler box of virus samples from a broken-down vehicle on the Kamituga road.