The first case of a more dangerous type of mpox, also known as monkeypox, was found outside of Africa in Sweden on Thursday, a day after the World Health Organization (WHO) declared a global health emergency.

The head of Sweden's public health agency, Olivia Wigzell, said a person in Sweden had become infected while they were staying in Africa in an area where there is currently a major outbreak of mpox Clade 1, per BBC News. She said the person is being treated in Stockholm and cautioned that this did not necessarily mean there's a risk to the broader population. The person infected tested positive for Clade 1b, which reportedly a "newer and more serious type," of the infection, the outlet states.

Director of WHO Tedros Adhanom Ghebreyesus stated in a press conference on Wednesday that his emergency committee advised him that "the situation constitutes a public emergency of international concern" and he accepted the advice. "The detection and rapid spread of a new clade of mpox" in Africa and its neighboring countries "is very worrying," he said, adding that "it's clear a coordinated international response is essential to stop these outbreaks and save lives."

The WHO said it was communicating with Sweden's health authorities on "how best to manage the first confirmed case of mpox Clade 1b."