Within a matter of days, over 50 cases of suspected and confirmed infection with the monkeypox virus have now been reported across Europe and North America, including the first reported case in the United States yesterday, said Massachusetts state officials; the case involved a man who had recently traveled to Quebec, Canada.

That adds the US and Canada to a growing list of European countries reporting monkeypox cases in an outbreak first spotted in the United Kingdom where a total of seven cases had been reported recently. Also on Wednesday, two more European countries, Spain and Portugal, reported a surge in monkeypox cases.

Suspected cases in Spain have climbed to 23, and Portugal is looking at more than 20 cases. Officials in Canada are also investigating more than a dozen cases in the eastern province of Quebec, with the Public Health Agency of Canada “collaborating closely” with international partners, including the US Centers for Disease Control and Prevention (CDC), the World Health Organization, and the UK Health Security Agency (UKHSA).

Many unknowns about linkage in the outbreak

There are many unknowns in Europe, the US, and Canada: whether the outbreaks are linked to each other or to cases in the UK; if so, whether the virus spread from the UK to Europe, or the reverse; or how long the virus has been spreading. Still, the quick accumulation of cases is ringing alarm bells.

“We have a sense that no one has their arms around this to know how large and expansive it might be,” CDC’s Jennifer McQuiston told STAT News.

Spain has already issued a nationwide alert in response to the growing number of cases, noting that the virus, typically transmitted via respiratory infection, has in fact been found to be spread through close contact during sex in cases outside of Africa.

“Monkeypox is spread by respiratory transmission, but the characteristics of the 23 suspected cases point towards transmission through mucus during sexual relations,” the Madrid regional health department was quoted as telling The Guardian.

The smallpox-related virus, which circulates widely in central and west Africa, is known to cause flu-like symptoms and heavy rash fluid-filled nodules on the limbs and other parts of the body. Although some forms of the virus have a 10% fatality rate, the west African variant which has infected people in the UK has been relatively milder than the central African strain, prevalent in the Democratic Republic of Congo (DRC).

DRC is also the country with the highest reported prevalence of monkeypox cases in Africa, with some 3,000 cases reported last year, WHO has said.

Unusual monkeypox transmission may be community-spread

While there have been previous reports of monkeypox cases outside of Africa, they were usually traced to infected travelers.

The recent exponential increase in reported cases in Europe and North America raises special concerns since many or most of those reportedly  infected have not travelled to monkeypox-endemic countries nor do they have links to prior cases. And that suggests that the virus is now being transmitted locally, reports the Center for Infectious Disease Research and Policy (CIDRAP).

“These latest cases, together with reports of cases in countries across Europe, confirms our initial concerns that there could be spread of monkeypox within our communities,” said Susan Hopkins, UKHSA Chief Medical Adviser, in a UK government statement.

Portuguese officials, likewise, have reported that among the cases identified there – all men located in or near the capital city of Lisbon – none travelled recently to Africa, nor were they in close contact with cases in the UK.

Additionally, most of the UK cases appear to have involved transmission in networks of men having sex with men, the World Health Organization confirmed in a media briefing on Tuesday.

WHO and national health agencies are thus exploring whether new forms of monkeypox transmission are emerging, such as through close contact during sex.

“We’re finding where we’re looking [in sexual health clinics],” said Maria Van Kerkhove, WHO Technical Lead on COVID-19, during WHO’s Tuesday briefing. Countries have so far been contacting sexual health clinics asking about patients with unusual rashes, but health care providers across the spectrum are advised to be on the lookout.

“We are particularly urging men who are gay and bisexual to be aware of any unusual rashes or lesions and to contact a sexual health service without delay if they have concerns,” urged Hopkins. See below our previous Health Policy Watch report on monkeypox, it’s origins and transmission:

Seven Confirmed Monkeypox Cases in UK Includes Sexually Transmitted Cluster

Image Credits: Tessa Davis/Twitter .