New Mpox strain discovered in Sweden, 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 the global outbreak from 2022 to 2023, is known for higher mortality rates and has not been seen outside of Africa to date.

Detection of Clade 1 Mpox in Sweden

On August 15, the Swedish Public Health Agency confirmed the detection of clade 1 mpox in a person undergoing treatment in Stockholm. This person is believed to have contracted the virus during a recent visit to a region of Africa where a large outbreak is ongoing. 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 the risk and response

Clade 1 mpox is known to have severe health consequences, with mortality rates ranging from 3% to 10%. This is in stark contrast to clade 2, which had much lower mortality rates during the 2022-2023 outbreak. Despite this, the Public Health Agency of Sweden has 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 treated about 300 cases of clade 2 mpox linked to the global outbreak. The country is prepared to use antivirals and may consider using a “ring” vaccination strategy to prevent further spread. The Public Health Agency continues to assess the need for new measures and takes the clade 1 mpox outbreak seriously.

Magnus Gisslén, state epidemiologist for the Public Health Agency of Sweden, said: “We are closely monitoring the outbreak and continuously assessing whether new measures are needed.” This proactive approach is crucial to manage the changing situation and prevent further spread of this deadly virus.