Sweden detects mpox variant for first time outside of Africa

Swedish officials said Thursday they have detected a version of mpox that only a day earlier prompted global health authorities to declare a health emergency, marking the first time that variant has been discovered outside of Africa.

The World Health Organization sounded an alarm Wednesday about the viral ailment amid a growing outbreak in Africa concentrated in the Democratic Republic of Congo that has spread to countries that never reported mpox cases before.

The ongoing African outbreak is driven by versions of the virus known as clade 1, including the offshoot clade 1b. Those versions have been associated with more severe illness and deaths than the clade 2 version responsible for the 2022 global outbreak.

Swedish officials said the patient was infected during a stay in a part of Africa where clade 1 is circulating and was diagnosed with that variant after seeking care in the Stockholm region. That patient has received care, said Magnus Gisslen, state epidemiologist at the Public Health Agency of Sweden.

Swedish officials said the risk to the public is considered low, in line with an assessment from the European Center for Disease Prevention and Control. But they said a new assessment is expected soon, with occasional cases related to travel anticipated.

Public health officials have stressed that the highest death rates associated with clade 1 versions may reflect infections striking more vulnerable people, including children, in areas with weak health care systems, rather than differences in the virus. The emergence of clade 1b has raised concerns because it is spreading sexually, the most efficient way for the virus to transmit and cross borders.