Dr Brian Ferguson of the University of Cambridge said the case in a Swedish traveller was concerning but not surprising, given the severity and spread of the outbreak in Africa.
“There will likely be more here and in other parts of the world as there are currently no mechanisms in place to stop imported cases of mpox happening,” he said.
The WHO on Wednesday declared the outbreak in Africa a public health emergency of international concern or PHEIC after cases in the Democratic Republic of Congo spread to nearby countries. A PHEIC is WHO’s highest level of alert.
There have been 27,000 cases and more than 1,100 deaths, mainly among children, in Congo since the current outbreak began in January 2023.
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WHO declares mpox a global health emergency as new form of virus emerges
WHO declares mpox a global health emergency as new form of virus emerges
The global vaccine group Gavi said it has up to US$500 million to spend on getting shots to countries affected by the escalating mpox outbreak in Africa.
Both US and Canadian officials have said they have not identified any cases so far.
“This is the first clade I mpox case to be reported outside of the African continent,” CDC spokesman David Daigle said in a statement, noting that the agency is watching the outbreak closely.
The CDC recently issued a Health Alert Network update and updated Travel Health Notice to tell US clinicians, travellers, and public health partners about the spread of clade I mpox into countries that have historically not reported cases of mpox.
Clade Ib, the strain of the virus behind the current outbreak, is a new variant of clade I that is endemic in the Congo. Clade Ib appears to spread more easily though routine close contact, including sexual contact.
Clade I mpox tends to cause a higher number of severe infections and have a higher mortality rate than clade II mpox, according to US health officials.
In 2022, WHO declared a public health emergency over an outbreak of mpox caused by clade II, which led to more than 95,000 cases across 115 non-endemic countries.
Meanwhile, Pakistan recorded on Friday the country’s first mpox case of the year.
“The affected person has come from a Gulf country,” a Ministry of Health statement said, adding the strain was yet to be confirmed.
The Pakistan patient is a 34-year-old man and being treated in Khyber Pakhtunkhwa province, said Irshad Roghani, director of public health there.
“This infection … is the first confirmed case we have this year,” he said.
“For genetic sequencing of the strain, we have sent samples to Islamabad.”