What is mpox, and why is this outbreak so concerning?

Article Summary #

The World Health Organization has declared the ongoing mpox outbreak in Africa a global health emergency. A deadlier strain of the virus, clade Ib, is spreading quickly in the Democratic Republic of Congo and has reached at least four previously unaffected countries. The risk of additional international spread is concerning. Mpox is a viral disease related to smallpox. The current outbreak is driven by clade I, which causes more severe disease. Some outbreaks of clade I mpox have killed up to 10% of people who get sick. The geographic pattern of the current outbreak is different than the outbreak two years ago, with more countries in Africa being affected. Vaccines to protect against mpox are available but not widely accessible in Africa.