On Thursday, the World Health Organization (WHO) warned that additional imported cases of a more dangerous strain of mpox in Europe are likely, following Sweden’s announcement of the first such infection outside Africa.
This outbreak, which has claimed hundreds of lives in the Democratic Republic of Congo (DRC), has raised global concern.
Sweden reported the case involving a traveler on the same day that the WHO declared the mpox surge in Africa a public health emergency of international concern—the highest level of alert.
The UN health agency expressed particular concern about the rising cases and fatalities in the DRC, as well as the spread of the virus to Burundi, Kenya, Rwanda, and Uganda.
Sweden’s Public Health Agency confirmed that it had detected the Clade 1b subclade of the virus, the same new strain that has been rapidly spreading in the DRC since September 2023. “A person who sought care in Stockholm has been diagnosed with mpox caused by the Clade 1 variant. It is the first case of Clade 1 to be diagnosed outside Africa,” state epidemiologist Magnus Gisslen stated.
The agency reassured the public that the presence of mpox in the country poses very low risk to the general population, a sentiment echoed by the European Centre for Disease Prevention and Control.
The WHO’s European regional office in Copenhagen is in discussions with Swedish authorities on how best to manage the newly detected case. “The confirmation of mpox Clade 1 in Sweden highlights the interconnectedness of our world,” the WHO said in a statement, adding that more imported cases in Europe are likely. The organization also stressed that travel restrictions and border closures should be avoided to prevent stigmatization.
The outbreak has been particularly severe in the DRC, where Health Minister Samuel-Roger Kamba reported 15,664 suspected cases and 548 deaths across all 26 provinces since the beginning of the year. In response, the government has implemented a national vaccination plan and strengthened disease surveillance at borders and checkpoints.
The U.S. Department of Health announced it would donate 50,000 doses of the FDA-approved JYNNEOS vaccine to the DRC as part of the response effort. Additionally, Danish drugmaker Bavarian Nordic is preparing to produce up to 10 million doses of its mpox vaccine by 2025.
Mpox, formerly known as monkeypox, was first discovered in monkeys in 1958 and in humans in 1970 in the DRC. It is an infectious disease transmitted from animals to humans, but can also spread through close human contact. The Clade 1b subclade, prevalent in Central Africa, is more virulent and deadly than the Clade 2b subclade, which caused a global outbreak in 2022.
That outbreak, primarily affecting gay and bisexual men, led to a public health emergency declared by the WHO from July 2022 to May 2023, with over 90,000 cases and around 140 deaths reported globally. The Clade 1b strain, however, poses a greater threat with a higher fatality rate.