There’s a monkeypox outbreak in European and North American countries but health officials are having difficulty finding out where people caught the monkeypox virus and how it is spreading.
The outbreak is small — so far fewer than 100 suspected cases, including eight in the United Kingdom, 20 in Portugal and 13 in Canada.
The most recent confirmed monkeypox infections were reported in Italy and Sweden, which followed Wednesday’s confirmation of cases in the US, Spain and Portugal.
The US Centers for Disease Control (CDC) and Prevention confirmed the first human case of Monkeypox in the US with Massachusetts health officials.
Monkeypox was first discovered in 1958 when two outbreaks of a pox-like disease occurred in colonies of monkeys kept for research, hence the name ‘monkeypox.’
The first human case of monkeypox was recorded in 1970 in the Democratic Republic of Congo during a period of intensified effort to eliminate smallpox.
Since then monkeypox has been reported in humans in other central and western African countries but there’s concern the virus may be spreading undetected through the world and possibly through a new route of transmission.
“This [outbreak] is rare and unusual,” epidemiologist Susan Hopkins, who’s the chief medical adviser of the U.K. Health Security Agency (UKHSA), said in a statement.
“Exactly where and how they [the people] acquired their infections remains under urgent investigation,” the agency said in the statement.
Monkeypox has not previously been described as a sexually transmitted infection, though the British cases predominantly involved gay or bisexual men who have sex with men (MSM) but have no travel links to a country where monkeypox is endemic.
Monkeypox can be a nasty illness; it causes fever, body aches, enlarged lymph nodes and eventually “pox,” or painful, fluid-filled blisters on the face, hands and feet. One version of monkeypox is quite deadly and kills up to 10% of people infected. The version currently in England is milder. Its fatality rate is less than 1%. A case generally resolves in two to four weeks.
Typically, people catch monkeypox from animals in West Africa or central Africa and import the virus to other countries. Person-to-person transmission isn’t common, as it requires close contact with bodily fluids, such as saliva from coughing or pus from the lesions. So the risk to the general population is low, the U.K. health agency notes.
But in England, 7 of the 8 cases don’t involve recent travel to Africa, suggesting the patients involved in those cases caught the virus in England. On top of that, those individuals haven’t had contact with the one patient known to have traveled to Nigeria, the UKHSA reported Tuesday. Together, this data suggests the virus is spreading in the community undetected.
“Presumably this is cryptic spread from an imported case(s),” virologist Angie Rasmussen of the Vaccine and Infectious Disease Organization tweeted on Monday.
In the U.S., the patient in Massachusetts had not recently traveled to countries where the disease occurs but had visited Canada.
In addition, there’s evidence the virus could be spreading through a new route: sexual contact. “What is even more bizarre is finding cases that appear to have acquired the infection via sexual contact,” epidemiologist Mateo Prochazka at the UKHSA tweeted. “This is a novel route of transmission that will have implications for outbreak response and control.”
“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,” epidemiologist Hopkins said in the UKHSA’s statement.
Scientists at the U.S. Centers for Disease Control and Prevention are watching the outbreak in Europe closely. “We do have a level of concern that this is very different than what we typically think of from monkeypox,” Jennifer McQuiston, a senior CDC official, told health news site STAT on Tuesday.
In 2019, the U.S. Food and Drug Administration approved the first vaccine for monkeypox, which also protects against smallpox. “This vaccine is also part of the Strategic National Stockpile (SNS), the nation’s largest supply of potentially life-saving pharmaceuticals and medical supplies for use in a public health emergency that is severe enough to cause local supplies to be depleted,” the agency said in a news release.