What We Know About Monkeypox So Far

A health official uses a thermal head to screen for monkeypox cases at Soekarno-Hatta International Airport in Tangerang, Indonesia, in 2019. Photo: Anadolu Agency/Getty Images

In recent weeks, monkeypox — a rare viral disease that has previously appeared mostly in central and western African countries, where it is endemic — has surfaced in more than a dozen countries including Spain, Portugal, Italy, Sweden, Germany, Canada, Australia, and the United States.

The form of monkeypox currently in circulation is thought to be mild and does not spread easily between people: Transmission requires close contact with an infected individual, animal, body fluids, or contaminated surface. Many of the cases identified in the U.K. were among men who’d had sexual contact with other infected men, but it is not strictly a sexually transmitted disease. Asked this week if the WHO believed this could grow into another pandemic, the World Health Organization’s technical lead for monkeypox, Rosamund Lewis, reportedly said, “We don’t know, but we don’t think so.”

Though experts have stressed that the public risk of contracting monkeypox remains low, President Joe Biden has said current outbreaks are something “everybody should be concerned about.” As of Thursday, May 26, the CDC reported nine monkeypox cases in seven states. And White House senior director for health security and biodefense recently warned, “We shouldn’t be surprised to see more cases reported in the US in the upcoming days.”

Here is what we know about the monkeypox cases so far.

What are the symptoms of monkeypox?

While monkeypox is increasingly associated with large, pus-filled lesions as pictured in news stories, there are a number of other symptoms associated with this virus. “The disease usually starts with nonspecific symptoms similar to what you might see with influenza: fever, headache, muscle aches,” says Adam Ratner, the director of pediatric infectious diseases at NYU Langone Health. “People who get it also tend to have large lymph nodes under their jaw.”

Within one to three days after the onset of these initial symptoms, a rash will usually appear. These usually appear first on the face or torso (though they tend to spread elsewhere) and “start as flat reddish areas that then become raised and then become fluid filled,” says Ratner. These rashes then open, scab over, and go away, though some scarring is possible.

How is monkeypox spread?

Monkeypox can spread through large respiratory droplets, which “travel shorter distances than aerosols do and don’t hang out in the air as much as aerosols do,” says Ratner. The monkeypox virus can also be spread through contact with lesions, especially if there is broken skin.

Though a number of current outbreaks can be traced to networks of men who have sex with men, monkeypox is not a sexually transmitted disease in the traditional senseit’s just that sex is one form of close contact through which monkeypox can be transmitted. “Right now, there is a sexually transmitted disease component, but you don’t have to have sex with someone to get it,” says Bernard Camins, the medical director for infection prevention at the Mount Sinai Health System, adding that people who live with infected persons would also be at risk.

Though concern surrounding monkeypox is not unreasonable, it’s likely amplified because of the ongoing COVID-19 pandemic, which Camins emphasizes is a very different virus. “Monkeypox is certainly not as contagious as smallpox, chicken pox, or COVID for that matter,” he says. “There is a respiratory component, but these are large droplets, which means that wearing a mask can protect you.”

Is monkeypox deadly?

On the whole, monkeypox tends to be a mild disease, says Ratner. “There’s a central African version and a west African version” of monkeypox, he explains. “To our best understanding through viral sequencing now, the cases we’re seeing now have all been of the west African kind, which is usually less severe.”

Mortality rates for these two types of monkeypox are generally cited as one percent for the west African type and 10 percent for the central African type, though Ratner cautions that the latter figure may be misleading: “Those numbers tend to be from outbreaks that are in places where there are higher numbers of malnourished individuals, and that’s a risk factor for severe disease, and immunocompromised people, which is also a risk factor.”

How is monkeypox treated?

Anyone with a suspected case of monkeypox should seek medical attention, at which point they will likely be isolated. But most people who become infected with monkeypox won’t get very sick and may not benefit from treatment as a result, says Ratner. From start to finish, most cases of monkeypox last a couple of weeks.

In some cases, says Camins, doctors may prescribe an antiviral drug called cidofovir, but he thinks it’s more likely that health officials will target close contacts of those infected for vaccination against smallpox, which also protects against monkeypox. Camins says it is unlikely there would be a mass vaccination campaign against monkeypox as the risk to the general public remains low.

What’s this about a monkeypox vaccine?

The US currently has two vaccines against monkeypox in addition to the antiviral treatments, though they are not widely available. However, CDC Director Dr. Rochelle Walensky said that the organization is ready to “move these products around the country so that they can be used for prevention or treatment for people who may benefit, wherever they may be.” Massachusetts has already gotten some doses of one of the vaccines, per CNN.

How can we prevent the spread of monkeypox?

Right now, there is nothing most people need to do about monkeypox; the current onus remains on government and health officials to pay close attention. “I think the important thing right now is surveillance for cases and getting a sense of what the scope of the problem is,” says Ratner. “Unless there’s been a fundamental change in the virus, and I don’t think there’s evidence of that right now, I think this is something that’s unlikely to cause a large population-level outbreak.”

Camins echoes this sentiment. “The general population should know about monkeypox but should remember that it’s really unlikely they’ll be exposed,” he says. “If, however, someone has recently traveled to an affected area and has a fever and a rash, they should get evaluated, and the same is true if you’ve been exposed to someone with those symptoms.”

What We Know About Monkeypox So Far