LONDON — Scientists who have monitored numerous outbreaks of monkeypox in Africa say they are baffled by the disease’s recent spread to Europe and North America.
Cases of the smallpox-related disease have previously only been seen among people with links to West and Central Africa. But over the past week, Britain, Spain, Portugal, Italy, the United States, Sweden and Canada have all reported infections, mostly in young men who had never traveled to Africa before.
There are currently about 80 confirmed cases worldwide and another 50 suspected cases, the World Health Organization (WHO) said. In Quebec, the first two cases were confirmed on Thursday. France, Germany, Belgium and Australia reported their first cases on Friday.
“I am stunned by this. Every day I wake up and there are more countries infected,” said Oyewale Tomori, a virologist who previously headed the Nigerian Academy of Sciences and sits on several WHO advisory boards.
“It’s not the kind of spread we’ve seen in West Africa, so there may be something new happening in the West,” he says.
To date, no one has died from the outbreak. Monkeypox usually causes fever, chills, rashes, and lesions on the face or genitals. The WHO estimates the disease kills up to one in 10 people, but smallpox vaccines are protective and some antiviral drugs are in development.
British health officials are investigating whether the disease is sexually transmitted. They asked doctors and nurses to be on the alert for potential cases, while ensuring the risk to the general population is low. The European Center for Disease Control and Prevention has recommended that all suspected cases be isolated and high-risk contacts offered the smallpox vaccine.
According to the WHO, Nigeria reports about 3000 cases of people infected with monkeypox per year. Outbreaks usually occur in rural areas, when people come into close contact with infected rats and squirrels, Tomori said. He said many cases probably go unreported.
“Atypical” epidemic
Dr Ifedayo Adetifa, head of the country’s Center for Disease Control, said none of the UK patients’ Nigerian contacts had developed symptoms and investigations were ongoing.
WHO director for Europe Dr Hans Kluge described the outbreak as ‘atypical’, saying the occurrence of the disease in so many countries across the continent suggested ‘transmission is ongoing since a while”. He mentioned that most European cases are mild.
The UK Health Security Agency reported 11 new cases of monkeypox on Friday, saying ‘a notable proportion’ of infections in the UK and Europe were in young men with no history of travel to Africa and who were gay , bisexual or had sex with men.
Authorities in Spain and Portugal also said their cases involved young men who mostly had sex with other men. They said these cases were detected when the men presented with lesions to sexual health clinics.
Experts have stressed that they do not know whether the disease is spread through sex or through other close sex-related contacts.
Nigeria has not experienced sexual transmission, Tomori said, but he noted that viruses that were not initially known to be sexually transmitted, such as Ebola, eventually turned out to be. after larger outbreaks showed different patterns of spread.
The same could be true for monkeypox, Tomori said.
In Germany, Health Minister Karl Lauterbach says the government is confident the outbreak could be contained. He said the virus was being sequenced to see if there were any genetic changes that could have made it more contagious.
Contribute to inadvertent spread
Rolf Gustafson, a professor of infectious diseases, told Swedish TV channel SVT it was “very hard” to imagine the situation could get worse.
“We will definitely find more cases in Sweden, but I don’t think there will be an outbreak in any way,” Gustafson said. Nothing suggests it at the moment.
Scientists have claimed that it is possible that the first patient of the epidemic caught the disease in Africa. However, they describe what is happening now as an exceptional situation.
“We have never seen anything like what is happening in Europe,” said the director of the African Center of Excellence for Genomics of Infectious Diseases, Christian Happi. We have seen nothing to indicate that monkeypox transmission patterns have changed in Africa. So if something different is happening in Europe, then Europe needs to investigate it.
Happi also pointed out that the suspension of smallpox vaccination campaigns after the disease was eradicated in 1980 could inadvertently contribute to the spread of monkeypox. Smallpox vaccines also protect against monkeypox, but mass vaccination was stopped decades ago.
“Apart from people in West and Central Africa who may have some immunity to monkeypox from past exposure, lack of smallpox vaccination means no one has any immunity against monkeypox,” said Happi.
Shabir Mahdi, professor of vaccination at the University of the Witwatersrand in Johannesburg, South Africa, said a detailed investigation of the outbreak in Europe, including to determine who the first patients were, was now essential.
“We really need to understand how it started and why the virus is now gaining traction,” he said. In Africa, there have been very controlled and infrequent outbreaks of monkeypox. If this is changing, we really need to understand why.”