Placide Mbala has been monitoring patients with the mpox virus in Kinshasa, Democratic Republic of Congo, for over 15 years. Now the head of epidemiology and global health at the National Institute of Biomedical Research, he suspected something important had changed when cases suddenly began surging across central Africa in 2024. Instead of seeing young children, who’d previously been most impacted by the disease, Mbala noticed an increase of infections among adults with localized lesions in the genital area. Through genomic analysis, Mbala discovered that the spike of new cases was not part of the clade IIb strain that was the origin of the 2022 epidemic, but a different sub-variant often transmitted sexually. This new strain was also more virulent.
His discovery helped alert local and international health officials to the new threat, and the World Health Organization declared it a global health emergency. The insight provided by Mbala has played a crucial role in motivating the international community to develop new testing strategies to pick up mutations, considering less than half of the people in Congo with mpox are tested. “The risk is that unless patients themselves come forward, we will have a silent transmission of the disease and nobody will know,” says Mbala.