The disease – which is more common to west and central Africa – has confirmed cases in the UK, Spain, Portugal, Belgium, France, Italy and Sweden. The US and Australia have also reported outbreaks.
The mild viral ilness produces symptoms including a fever, headaches and aching muscles, before later evolving into a distinctive bumpy skin rash.
“With several confirmed cases in the United Kingdom, Spain and Portugal, this is the largest and most widespread outbreak of monkeypox ever seen in Europe,” said Germany’s armed forces’ medical service, which detected its first case in the country on Friday.
First identified in monkeys, the disease typically spreads through close contact and has rarely spread outside Africa, so this series of cases has triggered concern among health officials.
Fabian Leendertz, from the Robert Koch Institute, described the outbreak as an epidemic, he said: “However it is very unlikely that this epidemic will last long. The cases can be well isolated via contact tracing and there are also drugs and effective vaccines that can be used if necessary.”
There isn’t a specific vaccine for monkeypox, but data shows that vaccines that were used to eradicate smallpox are up to 85% effective against monkeypox, according to the World Health Organisation (WHO).
Since 1970, monkeypox cases have been reported in 11 African countries, with Nigeria witnessing the largest outbreak in 2017, with 172 suspected cases of monkeypox identified and 61 confirmed cases.
The first European case was confirmed on May 7 in an individual who returned to England from Nigeria, and since then more than 100 cases have been reported.
The cause of the outbreak is unclear, although health authorities have said that there is potentially some degree of community spread.
In the UK, where 20 cases have been now confirmed, the UK Health Security Agency (UKHSA) said the recent cases in the country were predominantly among men who self-identified as gay, bisexual or men who have sex with men.
Dr Susan Hopkins, chief medical adviser to the UKHSA, said in a statement: “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.”
The 14 cases in Portugal that were all detected in sexual health clinics are also in men who self-identify as gay, bisexual or men who have sex with men.
It is too early to say if the illness has morphed into a sexually transmitted disease, said Alessio D’Amato, health commissioner of the Lazio region in Italy. Three cases have been reported so far in the country.
Sexual contact, by definition, is close contact, added Stuart Neil, professor of virology at Kings College London.
“The idea that there’s some sort of sexual transmission in this, I think, is a little bit of a stretch,” he said.
Additional reporting by Reuters