Few things are more unnerving three years into a pandemic than public health officials talking about unusual outbreaks of yet another virus, but here we are.
Since early last month, officials have been watching an uptick in cases of the monkeypox virus around the globe. While the virus is endemic in countries in central and west Africa, it’s now been detected in over 29 nations where it’s not typically found.
As of June 8th, there have been more than 1,000 cases in non-endemic countries, according to WHO Director-General Tedros Adhanom Ghebreyesus. In the United States, there are 33 confirmed cases, appearing in Arizona, California, Colorado, the District of Columbia, Florida, Georgia, Hawaii, Illinois, Massachusetts, New York, Pennsylvania, Texas, Utah, Virginia, and Washington. No deaths have been reported in non-endemic countries, but on the continent of Africa, where the virus is more prevalent, there have been 1400 cases and 66 deaths this year, according to the WHO.
Public health officials have been stumped by both the high number of monkeypox cases popping up in countries where the virus is not endemic as well as the unusually high number of mutations found in the viruses that virologists have sequenced. More research needs to be done to definitively determine what, if any, impact these mutations have on the trajectory of these outbreaks, or what other factors could be contributing to the high case rate.
Initial sequencing suggested the earliest cases were the type of Monkeypox virus associated with West Africa, which has a fatality rate of about 1 percent, according to the WHO. Confusingly, the WHO also says the fatality rate for monkeypox generally is between 3 and 6 percent. Those conflicting numbers may boil down to the fact that we “don’t understand mortality rates,” Maria Van Kerkhove, who leads the emerging diseases and zoonoses unit in the World Health Organization’s Health Emergencies Program, told STAT News. Unreported and undetected cases make it hard to predict an exact fatality rate.
Here’s what we know and don’t know about monkeypox and the current outbreaks.
What is monkeypox?
As the name suggests, monkeypox is in the same family of viruses as smallpox, though typically it is much less transmissible and far less severe than smallpox.
William Schaffner, an infectious disease expert at Vanderbilt University Medical School, tells Inverse the virus is typically found in small mammals in areas with tropical climates.
“Occasionally, it does get into primates, that's why the name monkeypox,” he says. “And of course, it can also get into people. It can be spread from person to person but not easily, you need very close and usually fairly sustained interpersonal contact, touching, kissing, and such.”
The World Health Organization notes that the longest known transmission chain of monkeypox is “nine generations,” meaning the last person to be infected in this chain was nine links away from the original sick person. That’s up from six generations previously, suggesting some increased transmissibility, though if that’s truly the case and if so, how much more transmissible has yet to be determined. It can be transmitted through contact with “bodily fluids, lesions on the skin, or on internal mucosal surfaces, such as in the mouth or throat, respiratory droplets, and contaminated objects.”
The first case in the 2022 outbreaks was fairly standard, the person had traveled to Nigeria, where the virus is commonly found. The others, however, haven’t always followed the same pattern: As of now, some patients recently confirmed to have monkeypox in the U.S. and Europe didn’t recently travel to an area where it’s common; how they got the virus is still unclear.
The unusual pattern may mean the virus has become significantly more transmissible, spreading through aerosols. Monkeypox is known, at times, to be airborne, though it’s unclear how common this is. Last week, the CDC appeared to suggest aerosol transmission was possible when they added a line to the monkeypox travel advisory page on their website that read “Wear a mask. Wearing a mask can help protect you from many diseases, including monkeypox.” On Monday night, that line was deleted. On Tuesday, the CDC said, they removed the mask recommendation because it caused “confusion.”
The virus has an unusually long incubation period — between five and 21 days — which may have contributed to people not knowing they were infected and thus transmitting the virus.
In an interview with STAT News, Andrea McCollum, who heads up poxvirus epidemiology in the CDC’s division of high consequence pathogens and pathology, said we may not have a full understanding of how this virus is transmitted generally.
“We don’t have really good contemporary estimates of R-naught. [R-naught is the figure that estimates how many people an infected person, on average, will infect.] We don’t really have any estimates of R-naught for the West African clade. Most of our estimates come from Congo Basin. And most of those estimates are less than 1. But I will remind you that you can have an R-naught of less than one and the agent can still be transmitted person to person,” McCollum told STAT.
What are the symptoms of monkeypox?
By all accounts, contracting monkeypox sounds unpleasant. Symptoms typically appear anywhere from 5 to 21 days after exposure.
The symptoms are initially very similar to a bad case of the flu, Schaffner says.
“When you get sick, fever is prominent, it can go up to 103. You get symptoms that are similar to other viral infections, muscle aches, pains, headache, and swollen lymph glands.”
A day or two after symptoms appear, an “unusual” rash will appear, typically on the extremities like the head, arms, legs, and notably the palm of the hands.
“The rash initially is a flat red rash, but then it quickly blisters up,” Schaffner says. “But it's not a thin blister. It's a rather thick, rubbery blister, that accumulates pus and gets yellow.”
Unlike bites from a similar-sounding virus, chickenpox, the lesions from monkeypox are more painful than itchy.
How do you prevent and treat monkeypox?
The smallpox vaccines offer some protection against monkeypox, Schaffner says, though the majority of Americans who have been vaccinated for smallpox were vaccinated so long ago that immunity has waned significantly. Still, he adds, “people who have received a smallpox vaccine may have less severe symptoms if they do contract monkeypox than someone who has not.”
There are no approved antivirals for monkeypox, though the Johns Hopkins Center for Health Security notes, “The antivirals cidofovir and brincidofovir could be used to treat monkeypox, though there is insufficient data on their effectiveness for monkeypox treatment in humans. However, animal studies have demonstrated effectiveness against monkeypox in certain mammalian species.”
Where have recent cases of monkeypox been found?
What’s unusual about these cases is how many of them have been found outside Central and West Africa. Cases have now been reported in more than 29 countries where the virus is not endemic, including the United States, Canada, the UK, Portugal, Germany, the Netherland, Sweden, and Italy.
That’s certainly concerning, Schaffner says, but perhaps not as concerning as some on social media have posited where conspiracy theories and general panic abound.
In some cases, the instinct to panic is likely a trauma response to living through years of a global pandemic.
“We're all infection and pandemic sensitive, I recognize that,” Schaffner says. “But I think the important thing is public health officials picked this up right away. They’re doing investigations and clinicians are treating the patients. Will there be more cases? Of course. The harder you look as you’re getting into an outbreak, the more you’re going to find.”
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