London – Scientists who have monitored numerous outbreaks of monkeypox in Africa say they are puzzled by the recent spread of the disease in Europe and North America.
Previously, cases of the smallpox-related illness had only been seen among people with ties to central and western Africa. But last week, Britain, Spain, Portugal, Italy, the US, Sweden and Canada reported infections, mostly in young men who had not previously traveled to Africa.
France, Germany, Belgium and Australia confirmed their first cases on Friday.
‘I’m 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 who sits on several advisory councils to the World Health Organization.
“This is not the kind of spread that we have seen in West Africa, so something new may be happening in the West,” he said.
To date, no one has died in the outbreak. Monkeypox usually causes fever, chills, rash, and lesions on the face, hands, or genitals. The WHO estimates that the disease is fatal to 1 in 10 people, but smallpox vaccines protect and some antiviral drugs are in development.
British health officials are exploring whether the disease is sexually transmitted. Health officials have asked doctors and nurses to be on the alert for possible cases, but said the risk to the general population is low. The European Center for Disease Control and Prevention recommended isolating all suspected cases and offering the smallpox vaccine to high-risk contacts.
Nigeria reports about 3,000 cases of monkeypox a year, the WHO said. Outbreaks typically occur in rural areas, when people have close contact with infected rats and squirrels, Tomori said. She said many cases are likely to be missed.
Dr. Ifedayo Adetifa, head of the country’s Center for Disease Control, said none of the British patients’ Nigerian contacts have developed symptoms and investigations are ongoing.
The WHO director for Europe, Dr. Hans Kluge, described the outbreak as “atypical” and said the appearance of the disease in so many countries on the continent suggested that “transmission has been ongoing for some time”. He said most European cases are mild.
On Friday, Britain’s Health Security Agency reported 11 new cases of monkeypox, saying “a notable proportion” of the most recent infections in the UK and Europe have been in young men with no history of travel to Africa. who had sex with men. Authorities in Spain and Portugal said their cases were the same.
Experts have stressed that they do not know if the disease is spread through sex or other close contact related to sex.
Nigeria has not seen sexual transmission, Tomori said, but noted that viruses initially not known to be transmitted through sex, such as Ebola, were later shown to do so after larger epidemics showed different patterns of spread.
The same could happen with monkeypox, Tomori said.
In Germany, Health Minister Karl Lauterbach said the government was confident the outbreak could be contained. He said the virus was being sequenced to see if there were any genetic changes that might have made it more infectious.
Rolf Gustafson, professor of infectious diseases, told Swedish broadcaster SVT that it was “very difficult” to imagine the situation could get worse.
“Certainly we will find some more cases in Sweden, but I don’t think there is an epidemic in any way,” Gustafson said. ‘There is nothing to suggest that at this time.’
The scientists said that while it is possible that the first patient in the outbreak contracted the disease while in Africa, what is happening now is rare.
“We have never seen anything like what is happening in Europe,” said Christian Happi, director of the African Center of Excellence for Infectious Disease Genomics. “We haven’t seen anything to indicate that monkeypox transmission patterns have changed in Africa. So if something different is happening in Europe, then Europe needs to look into that.’
Happi also noted that the suspension of smallpox vaccination campaigns after the disease was eradicated in 1980 could be inadvertently contributing to the spread of monkeypox. Smallpox vaccines also protect against monkeypox, but mass immunization stopped decades ago.
“Apart from people in West and Central Africa who may have some immunity to monkeypox from past exposure, not having any smallpox vaccine means no one has any immunity to monkeypox,” Happi said.
Shabir Mahdi, a professor of vaccinology at the University of the Witwatersrand in Johannesburg, said a detailed investigation of the outbreak in Europe, including determining who the first patients were, is now essential.
“We need to really understand how this started and why the virus is now gaining ground,” he said. ‘In Africa, there have been very controlled and infrequent outbreaks of monkeypox. If that is changing now, we really need to understand why.