What To Know About How Monkeypox Spreads—And Whether You Should Wear A Mask

The Centers for Disease Control and Prevention sparked confusion over monkeypox this week after deleting a recommendation for travelers to wear face masks to protect against the disease, a u-turn that shed light on the different ways the virus spreads amid escalating outbreaks across Europe and North America—here’s what to know about how the disease is transmitted.

If monkeypox can be transmitted sexually. A significant portion of the monkeypox cases identified in Europe and the U.K. have been among men who identify as gay or bisexual or have sex with other men with no history of travel to parts of Africa where monkeypox is endemic. While the virus is not known to be sexually transmitted—though a degree of close physical contact can be assumed—the pattern had scientists wondering if other modes of transmission were involved and experts have cautioned against stigmatizing members of the community.

Experts stress the risk from monkeypox is not limited to men who have sex with men and note the pattern could be explained by other factors. These could include health officials searching for, and thus finding, more cases within this group, members of the community being more proactive about their sexual health and more likely to visit clinics or the disease spreading thorugh sexual and social networks.

Researchers in Europe recently detected monkeypox virus in the semen of several patients, however, suggesting direct sexual transmission may be possible. Further research will be needed to determine whether this is the case, Dunning said. It’s not clear how the virus came to be in the seminal fluid or whether it was “added” at some point after ejaculation, he explained.

On Monday, the CDC raised its alert on monkeypox to Level 2—the level below advising against non-essential travel—updating its guidance and encouraging travelers to “practice enhanced precautions.” The guidance, which stressed the risk to the general public is “low,” advised those traveling to areas where there’s a monkeypox outbreak to avoid contact with sick people, contaminated materials and wild animals.

It also suggested travelers wear masks to help protect against monkeypox, though the agency quietly removed this recommendation, stating it had “caused confusion.” The agency does still recommend face masks, alongside other protective gear, for those who may be in close contact with a confirmed monkeypox patient and health workers caring for monkeypox patients. Dr. Hugh Adler from the Liverpool School of Tropical Medicine and Oxford’s Dunning both told Forbes masks are worn in clinical settings as part of a standard set of protective equipment for dealing with diseases like monkeypox.

On their own, masks may not be that useful in protecting against monkeypox given the multiple ways the disease can spread, they added. Given the very low risk of the general public coming into contact with someone with monkeypox, Adler said wearing masks doesn’t make a lot of sense. Dunning said the debate over masks is similar to discussions going on around the world with several other emerging infections and is “heavily influenced” by the Covid-19 pandemic.

45. That’s how many cases of monkeypox have been confirmed in the U.S. as of Thursday, according to the CDC. More than 1,300 cases have been confirmed in nearly 30 countries outside of Africa, according to public health data compiled by Global.Health, a team of researchers and technologists tracking the outbreak. The majority of these are in Europe—the U.K. has identified 321 cases, Spain 198, Portugal 191 and Germany 113—with a notable cluster of 110 cases in Canada. More cases are suspected but not confirmed.

Orthopoxviruses like monkeypox are “hardy and stable” and can survive for weeks or months in shed skin flakes and dust if the conditions are right, Oxford’s Dunning told Forbes. This means items like contaminated bedding or towels used by monkeypox patients could theoretically pose an infection risk for a long time. “Clouds” of skin flakes or dust that might form when changing the bed of an infected person could, for example, pose a risk of infection, Dunning added, though more research will be needed to examine the possibility.

Monkeypox gaining a foothold. Monkeypox is not a new virus and is a well-known entity that has been circulating in parts of Central and Western Africa for decades. It’s typically mild and goes away on its own in a month or so—though it can be lethal and is more dangerous for children and pregnant people—and there are several useful vaccines and treatments available designed to tackle smallpox, a similar virus that has been eradicated.

Experts, including WHO chief Dr. Tedros Adhanom Ghebreyesus, say the sudden and unexpected appearance of monkeypox in multiple countries at once suggests the virus may have been circulating undetected in non-endemic countries for some time, though it’s unclear for how long. While Tedros said it’s not too late to contain the outbreaks at the moment, he warned there is a “real” risk of the virus “becoming established in non-endemic countries.”

It’s possible the virus could spread to wild animal populations and gain a foothold outside of Africa that way, several researchers studying how viruses spread from animals to humans told Forbes. Rodents—which are suspected of harboring the virus in Africa—and squirrels are the most likely animal reservoirs in the U.S., University of Minnesota virologist Matthew Aliota said, and Georgetown University’s Ellen Carlin said the animals should be an “important planning consideration” for officials tackling the outbreak.