New Mpox strain reported in Sweden marks first case outside Africa

Sweden has reported its first case of clade 1 mpox (formerly known as monkeypox), a more severe variant of the virus previously confined to Africa. The announcement follows the World Health Organization (WHO) declaring the mpox outbreak in Africa a global health emergency. Clade 1, unlike clade 2, which caused a global outbreak in 2022–2023, is known for higher mortality rates and has not been observed outside of Africa until now.

Detection of Mpox clade 1 in Sweden

On August 15, the Public Health Agency of Sweden confirmed the detection of mpox clade 1 in a person treated in Stockholm. The person is believed to have contracted the virus during a recent visit to a region of Africa that has been experiencing a major outbreak. The detection of this more dangerous strain, which has previously been a major problem in countries such as the Democratic Republic of Congo (DRC), Burundi and the Central African Republic, marks a new phase in the global spread of mpox.

Understanding Risk and Response

Clade 1 mpox is known for its severe health effects, with case fatality rates ranging from 3% to 10%. This is in stark contrast to clade 2, which had much lower fatality rates during the 2022-2023 epidemic. Despite this, the Public Health Agency of Sweden assured that the risk to the general population remains very low. They stressed that while the new case does not require additional infection control measures, the situation is being closely monitored.

Public health measures and future prospects

Sweden has previously managed about 300 cases of clade 2 mpox associated with the global outbreak. The country is prepared to use antiviral drugs and could consider a “ring” vaccination strategy to prevent further spread. The Public Health Agency continues to assess the need for new measures and is taking the clade 1 mpox outbreak seriously.

Magnus Gisslén, state epidemiologist at the Public Health Agency of Sweden, said: “We are closely monitoring the outbreak and constantly assessing whether new measures are needed.” This proactive approach is crucial to managing the evolving situation and preventing further spread of this deadly virus.