Monkeypox has likely spread undetected ‘for some time’: WHO

The appearance of hundreds of monkeypox cases in several parts of the world suggests there may have been undetected transmission, says the head of the United Nations health agency.

The World Health Organization (WHO) has said that hundreds of monkeypox cases have surfaced beyond the African countries where the disease is typically found, warning that the virus has likely been spreading under the radar.

“Investigations are ongoing, but the sudden appearance of monkeypox in many countries at the same time suggests there may have been undetected transmission for some time,” WHO Director-General Tedros Adhanom Ghebreyesus told reporters on Wednesday.

Since the United Kingdom first reported a confirmed monkeypox case on May 7, more than 550 confirmed cases of the disease have been verified in 30 countries outside of the west and central African nations where it is endemic, the WHO said.

The United Nations health agency’s top monkeypox expert Rosamund Lewis said that the appearance of so many cases across much of Europe and other countries where it has not been seen before “is clearly a cause for concern, and it does suggest undetected transmission for a while”.

“We don’t know if it is weeks, months or possibly a couple for years,” she said, adding that “we don’t really know if it is too late to contain”.

Monkeypox is related to smallpox, which killed millions around the world every year before it was eradicated in 1980.

But monkeypox, which spreads through close contact, is much less severe, with symptoms typically including a high fever and a blistery chickenpox-like rash that clears up after a few weeks.

So far, most cases have been reported among men who have sex with men, although experts stress there is no evidence that monkeypox is transmitted sexually.