Sweden announced on Thursday the confirmation of a case of the more contagious strain of mpox that is currently prevalent in central and eastern Africa. This marks the first known infection of this strain outside of the African continent.
On Wednesday, the World Health Organization (WHO) designated mpox—previously referred to as monkeypox—as a global public health emergency for the second time in two years, following an outbreak in the Democratic Republic of Congo that has spread to 12 additional countries in the region.
During a news conference, Health and Social Affairs Minister Jakob Forssmed stated, “We have now also during the afternoon had confirmation that we have one case in Sweden of the more grave type of mpox, the one called clade I.”
Mpox is a viral infection that spreads through close contact and is divided into two distinct viral groups known as clades: clade I and clade II. The strain that became widespread in 2022, prompting the WHO’s initial public health emergency declaration, was a variant of clade II. In contrast, the ongoing outbreak involves clade I, which is associated with a potentially higher risk of severe illness and greater mortality, according to the Public Health Agency of Sweden.
The agency reported that the patient in Sweden sought treatment in Stockholm after traveling to Africa. The clade I strain linked to the outbreak in Congo appears to be highly transmissible through routine close contact, such as interactions within a household. This contrasts with the clade II strain, which was primarily transmitted through sexual contact among men who have sex with men during the earlier outbreak.