TTwo more European countries reported unusual cases of monkeypox on Wednesday, a development that suggests an outbreak first spotted in the UK is more widespread than first thought.
News of cases in more countries prompted a senior official at the Centers for Disease Control and Prevention to warn that cases are likely to be detected in the United States.
“I think we have concerns that there could be cases in the United States. I don’t know if we have a strong eye on people who might come forward with what seems like a minor skin rash illness or something,” said Jennifer McQuiston, deputy director of the CDC’s Serious Consequence Infectious Diseases Division and Pathology Division.
“Given that we have now seen confirmed cases from Portugal and suspected cases from Spain, we see this escalation of confirmed and suspected cases worldwide, we feel like nobody has their arms around them to know how big and extended it could be. And given the amount of travel between the United States and Europe, I’m very confident that we’ll see cases in the United States,” McQuiston said in an interview with STAT.
Spain said it was investigating eight suspected cases and Portugal said it was investigating more than 20 suspected cases, five of which have already been confirmed. It is not clear at this time whether the outbreaks are linked to each other or to that in the UK, where nine confirmed and one probable cases have been reported.
If they are linked, it is not yet clear whether the virus has spread from the UK to Europe or vice versa. It is also not known how long the virus has been spreading in these countries.
Some of the cases have been detected in men who have sex with men, raising the possibility that it could spread more than previously identified, said Michael Osterholm, director of the University of Minnesota’s Center for Infectious Disease Research and Policy.
“There could be dynamic transmission here, which we just didn’t appreciate given the potential number of contacts,” he said.
Tom Inglesby, director of the Center for Health Security at the Johns Hopkins Bloomberg School of Public Health, said a number of countries outside of central and west Africa where monkeypox is more common have experience in dealing with the introduction of the virus, so there are there is a possibility that the outbreaks will be “relatively small.”
“I think that’s still likely given the past,” Inglesby told STAT. “But on the other hand, this is starting with a much stronger foothold, in a much more distributed way, and we don’t understand how it got … into these networks.”
“This could have the potential to move and will require a fairly strong public education effort in affected communities, and perhaps even further, for people to recognize the possibility of monkeypox infection,” he said.
Britain’s Health Security Agency announced on Wednesday that it had detected two more cases, bringing the number reported there to nine this month. Before this outbreak, the UK had only detected seven cases of monkeypox. The two most recent cases had not traveled to countries where the monkeypox virus is endemic and have no known links to any of the previous cases, “so it’s possible they acquired the infection through community transmission,” the said agency in a statement, adding the most recent cases have mostly involved men who identify as gay or bisexual or have sex with men.
It seems that in at least some European cases, the same dynamic is at play. Spain’s Health Ministry reported that the eight suspected cases were discovered by a sexual health clinic in Madrid, according to news reports.
Portuguese authorities did not reveal how the cases there had been discovered, but said they were all males and most were young.
The rapid accumulation of cases is ringing alarm bells.
On Tuesday, the CDC signaled it was concerned about the status of the outbreak in the UK and the possibility of cases being found in other countries.
“We have a level of concern that this is very different than what we typically think of monkeypox,” McQuiston said.
“We don’t understand how many other cases there could be in the UK, for example, with undefined chains of transmission. We have a feeling that there may be some unusual modes of transmission through intimate contact or some form of close personal contact that we have not previously associated with monkeypox. And I think there’s a lot of travel between the UK and the US and other global areas,” she said in an interview.
The World Health Organization also expressed concern, saying a shift in the epidemiology of the disease in countries where the virus is endemic that has occurred in recent years needs to be investigated.
“We are seeing a shift in the age distribution of cases. We are seeing a shift in the geographical distribution of cases,” said Michael Ryan, Executive Director of WHO’s Public Health Emergencies Programme.
“We really need to understand this deep ecology. We really need to understand human behavior in these regions and try to prevent the disease from even reaching humans.”
The monkeypox virus is related to the variola virus, which caused smallpox, a once-dreaded disease that was declared eradicated in 1980. The symptoms of monkeypox are similar but milder than smallpox.
Infected people develop flu-like symptoms – fever, body aches, chills – but also swollen lymph nodes. One to three days after the onset of the fever, a prominent rash appears, often starting on the face. Many conditions can cause rashes, but monkeypox rash has some unusual features, most notably the fact that blisters can form on the palms of the hands.
In countries where it is endemic, the virus is believed to spread primarily from infected animals to humans when humans kill or prepare bushmeat for consumption.
Once the virus jumps to humans, human-to-human transmission can occur through respiratory droplets — virus-laced saliva that can infect the linings of the eyes, nose and throat — or through contact with monkeypox lesions or body fluids containing the virus, which penetrate through small skin incisions penetration. It can also be transmitted through contact with clothing or bedding contaminated with material from monkeypox lesions.
Cases outside of Africa have been rare, although there was a large outbreak in the United States in 2003 involving 47 confirmed and probable cases in six states. This outbreak, the first to be reported from outside Africa, has been traced to small mammal imports from Ghana.
However, in recent years there has been a slight increase in exported cases of monkeypox. The US detected two in 2021, both in travelers who had returned from Nigeria. The UK has seen multiple imports in recent years, and Israel and Singapore have also spotted cases.
McQuiston said the number of cases exported, particularly from Nigeria, seemed at odds with the reported number of cases in the country itself.
“I think we’re concerned about the number of exported cases in travelers that we’ve seen. And to have so many of them in recent years is just an indication to us that there are a lot more monkeypox transmissions in Nigeria than maybe that [official] Numbers would suggest that,” she said.
“And I think it’s also a sign for us that the more traditional routes of transmission that we’re thinking about, like hunting wild animals, exposure to bushmeat, living at this interface between the jungle and small communities, not being a driver seem transference in relation to what we see. And that lets us cast a broader net about what risk factors might be.”