Monkeypox is not known to spread easily between humans. The fact that cases are emerging in multiple countries at once – with evidence of “persistent” transmission in humans – is striking, said Aris Katzourakis, professor of evolution and genomics at Oxford University.
“Either bad luck or something very unusual is happening here,” said Katzourakis.
Monkeypox is named after the animals in which it was discovered. According to the Centers for Disease Control and Prevention, the disease emerged in monkeys kept for research in 1958 — more than a decade before a human case was identified in the Democratic Republic of the Congo.
Mass vaccination against smallpox “probably” curbed monkeypox infections in humans for a time, researchers wrote in a 2005 article. But cases have resurfaced, partly thanks to lack of immunity in later generations, they say. More than 450 cases have been reported in Nigeria since 2017, according to the CDC.
CDC scientists traveled to this remote African village to look for the monkeypox virus
Monkeypox infections typically last two to four weeks, the CDC says, and begin with the flu Symptoms and swelling of the lymph nodes. Eventually, fluid-filled bumps — or “pox” — spread across the skin.
The disease can spread through contact with animals, infected people and materials used by infected people, health officials say. Examples listed by the CDC include contact with bodily fluids, contact with monkeypox wounds, and infection through “respiratory droplets” in a “close environment” such as a shared household.
Monkeypox can be deadly, but two main strains of the virus carry different risks. According to the World Health Organization, it has been found that around 1 in 10 people infected with a strain from the Congo Basin dies, while a West African strain appeared to be fatal in around 1 in 100 infected.
This milder strain is the one infecting people hospitalized in the UK, health officials said. It is not clear what strain the Massachusetts patient contracted.
How concerned should we be? How does that compare to Covid-19?
Experts emphasize that monkeypox is different from the coronavirus that has turned the world upside down.
Monkeypox is highly visible, making contact tracing and isolation easier. An existing smallpox vaccine could help protect the public if needed, Katzourakis said. And “we don’t have the potential for something to spread around the world at the rate we’ve seen with Covid,” he said, because monkeypox is less easily transmitted between humans.
Still, the recent spate of cases stands out, Katzourakis said. The longer it lasts, the greater the chance that the virus will mutate and improve its transmissibility, just like the novel coronavirus.
Outbreaks of monkeypox have typically been small, with patients in the single digits, said Tom Inglesby, director of the Johns Hopkins Center for Health Security. “So I think the risk to the general public at this point is very, very low based on the information we have.”
But he agreed that the recent cases raise many questions. “We don’t really have a feel for what’s driving it yet. … There is no identified travel link that brings these cases all together,” he said.
Health officials have recently identified cases in men having sex with other men — a pattern that’s crucial to understand, Inglesby said, since officials have not previously considered sexual orientation a risk factor for monkeypox.
Has monkeypox ever made it to the United States?
Monkeypox first entered the United States — and the Western Hemisphere — in 2003, researchers say. More than 70 cases have been reported in the Midwest, mostly among people exposed to prairie dogs that appear to have been infected by rodents native to Ghana, according to the CDC.
Two children became seriously ill and recovered, the CDC said.
The infection reported Wednesday in Massachusetts is the first case of monkeypox identified in the United States this year, health officials said. Texas and Maryland each reported an infection in “persons who recently traveled to Nigeria” last year, the Massachusetts Department of Health said.
Rare monkeypox virus reported in Dallas
Where else has monkeypox been found this month?
The UK and Portugal announced confirmed cases, while Spanish authorities said on Wednesday they were investigating more than 20 suspected cases. The first known patient in the UK recently traveled to Nigeria, officials said.
The WHO said the person developed a rash in late April, just before leaving Africa. People identified as contacts have yet to report “compatible symptoms,” the global health organization said Monday.
But other cases have surfaced.
British health authorities announced two new infections on Wednesday, bringing the total to nine confirmed in England since May 6. Community transmission.
The latest cases have been “predominantly in gay, bisexual or men who have sex with men,” the UK Health Security Agency (UKHSA) said. The agency advises people in these groups to “be particularly alert for any unusual rashes or lesions on any part of their body.”
The WHO said it had learned of seven confirmed or probable cases – including three in one family – which appear to have been “acquired locally in the UK”.
Portugal’s Directorate General of Health, meanwhile, said more than 20 “suspected cases” had been identified this month. Five of them are confirmed, the agency said, and the infections are concentrated in young men.
What do we know about the US case?
A man who recently traveled to Canada was tested for the virus on Tuesday, and the infection was confirmed by the CDC on Wednesday, the Massachusetts Department of Health said in a statement.
The CDC is monitoring six Americans after they were seated near a British patient on a plane, CDC medical officer Agam Rao told the Washington Post on Wednesday. None of the patients showed any signs of monkeypox symptoms.
US officials said clinicians should consider a diagnosis of monkeypox in people with an otherwise unexplained rash who have traveled to a country where there has been a confirmed case, who has been in contact with a potentially infected person, or who is a male, who had sexual contact with other men.
The CDC is working with colleagues in other countries to compile information that can answer many of the experts’ questions.
“We’re just getting started with all of this to really understand the scope and why,” Rao said. “We’re very much in response mode, where we’re trying to identify cases, identify potential contacts and make sure we’re making the right recommendations to all of those people, including the healthcare workers who are caring for the patient.”
The disease is so rare, Johns Hopkins’ Inglesby said, that “most clinicians in America won’t see a case in their lifetime” — so communication about monkeypox will be important to ensure doctors are paying attention to symptoms.
Another top priority, he said, is to get more information about links between widespread infections. Is the disease spreading to other countries independently of West and Central Africa? Or do cases spread through networks of people?
“It’s going to be very important for us to understand that, because once you understand how cases spread … we have an opportunity to intervene,” Inglesby said.
Getting the genetic sequence of the virus behind the recent cases will help scientists confirm if they are dealing with a new strain of monkeypox. Unlike influenza or the coronavirus, Inglesby said researchers haven’t seen much change in monkeypox over the years, “and it’s going to be important to make sure it stays that way.”
Thanks to global trade and travel, smallpox viruses can spread further, experts say. The eradication of smallpox in 1980 helped the remaining smallpoxviruses overcome dwindling protection, said Anne Rimoin, an epidemiologist at the University of California, Los Angeles who has studied monkeypox for two decades.
“No good deed goes unpunished,” said Rimoin. “You declare that you can eradicate one pathogen, but you could leave room for another to emerge.”
Rao said that while researchers have noticed an increase in monkeypox prevalence since the end of the smallpox vaccine campaign, other factors have been linked to the infections, including climate change and other environmental changes that have led to more human-animal interactions .
“We’re just getting to a point where we really need to figure out why this is happening before we can start proposing solutions like vaccinations,” Rao said. “It’s just unexpected. We wouldn’t have recommended that if you’d asked me two weeks ago because the risk to the general population is extremely rare.”