Sweden reports first case outside Africa of the more dangerous mpox strain

Sweden has confirmed the first case of the more deadly mpox variant outside Africa, just a day after the World Health Organization declared a global public health emergency.

The infected individual contracted the virus while staying in a region of Africa affected by the mpox outbreak, according to a statement released by the Swedish Public Health Agency today.

“This particular case doesn’t require any additional infection control measures, but we take the outbreak of mpox clade I very seriously. We are closely monitoring the situation and continuously evaluating whether new actions are needed,” said Magnus Gisslén, Sweden’s state epidemiologist.

The European Centres for Disease Prevention and Control (ECDC) is expected to release a new risk assessment on mpox soon, the agency added. In the meantime, there may be more “isolated import cases.”

Mpox clade I is linked to more severe illness and higher mortality rates compared to clade II, which was prevalent during the 2022 outbreak in Europe and North America. Clade I also appears to impact children more severely.

Paul Hunter, a professor of medicine at the University of East Anglia, stated on Times Radio that clade I is "almost certainly" already present in the U.K.

Clade I is spreading rapidly in the Democratic Republic of the Congo and neighboring countries, leading the WHO to declare a public health emergency of international concern.

The first documented case of sexually transmitted mpox clade I in the DRC involved a Belgian resident likely exposed to the virus there, but researchers later found no evidence of clade I circulating in Belgium.