France, Germany, Belgium and Australia confirmed their first monkeypox event on Friday.
“I am just shocked. Every day I wake up and more countries are infected, ”said Wewale Tomori, a former virologist who heads the Nigerian Academy of Sciences and who sits on several advisory boards of the World Health Organization.
“It’s not the kind of expansion we’ve seen in West Africa, so something new could happen in the West,” he said.
One of the theories British health officials are exploring is whether the disease is sexually transmitted. Health officials have called on doctors and nurses to be cautious, but said the general public is at lower risk.
Outbreaks in Nigeria, which report about 3,000 monkeypox cases a year, usually occur in rural areas, where people have close contact with infected rats and squirrels, according to Tomori. He said the disease does not spread very easily and many cases are likely to be missed.
“Unless the person ends up in an advanced health center, they don’t pay attention to the surveillance system,” he said.
Tomori hoped that the presence of monkeypox across Europe and other western countries would lead to a more scientific understanding of the disease.
The head of the World Health Organization on Emergency Response, Dr. Ibrahima Sosfal, acknowledged this week that “the dynamics of transmission, clinical features (and) epidemiology were still very unknown.”
British officials have so far reported nine cases of monkeypox, citing recent incidents in all young people who had no history of traveling to Africa and had sex with homosexuals, bisexuals or men.
Authorities in Spain and Portugal also said their cases were among young men who had sex mostly with other men and said the cases were raised when men brought wounds to sexual health clinics.
Experts say they do not know if the disease is spread through sex, or through other close sexual contact.
“This is not something we have seen in Nigeria,” said virologist Tomori. He said that viruses, such as Ebola, were not initially known to be transmitted sexually, but were later shown to show different types of major epidemics.
The same could be said of monkeypox, Tomori said. “We have to go back through our records to see if this can happen between husband and wife,” he said.
In Germany, Health Minister Karl Lauterbach says the government is confident the outbreak can be controlled. He said sequencing was being done to see if there were any genetic mutations that could make the virus more contagious.
Scientists say the first outbreak of the disease was contracted while in Africa, but what is happening now is exceptional.
“We have never seen anything like what is happening in Europe,” said Christian Happy, director of the African Center of Excellence for Genomics of Infectious Diseases. “We haven’t seen anything like the fact that the types of monkeypox infections in Africa have changed, so if something different is happening in Europe, then Europe needs to investigate.”
Happy further noted that the suspension of the smallpox vaccine campaign 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 discontinued decades ago.
“With the exception of people in West and Central Africa who may have some resistance to monkeypox from past exposure, not having a smallpox vaccine means that no one is immune to monkeypox.”
Shabir Mahdi, a professor of vaccines at the University of Witwatersrand in Johannesburg, said a detailed investigation into the outbreak in Europe was now complicated, including determining who the first patients were.
“We really need to understand how it started and why the virus is gaining traction now,” he said. “In Africa, there has been a very controlled and rare outbreak of monkeypox. If that changes now, then we really need to understand why. “
Gair Mulson in Berlin and John Leicester in Paris contributed to this report.