youuntil recently, monkeypox rarely spread from person to person. In 2005, a study declared a cluster of six cases in the Republic of the Congo “the longest continuous chain of human monkeypox yet fully documented”.
That has changed to say the least. So far this year, more than 25,000 cases of monkeypox have been recorded in 83 countries – and human-to-human transmission is clearly widespread.
How does monkeypox spread among humans? Research is ongoing and findings on monkey pox transmission may develop over time. But this is what the latest science suggests.
Most cases were once linked to infected animals
According to the World Health Organization (WHO), the first human case of monkey pox was diagnosed in 1970 in a baby living in the Democratic Republic of Congo. Decades after that, cases were quite rare and often linked to contact with infected animals. The US had a minor outbreak in 2003, with 47 human cases associated with contact with prairie dogs as pets.
Things changed in 2017, when a fairly large human outbreak began in Nigeria. Doctors there diagnosed cases in young men who had not been exposed to infected animals and had lesions on their genitals, as NPR reported. Nigerian researchers published a 2019 study on the outbreak raising the possibility of sexual transmission, but the theory then gained little traction. “People tend to snag” [onto] which is tradition, and the tradition is that monkeypox is passed from animals to humans,” said co-author Dr. Dimie Ogoina, President of the Nigeria Infectious Diseases Society.
Most monkeypox cases in the ongoing outbreak are linked to sex
As the current outbreak shows, human-to-human transmission of monkeypox occurs — and sexual activity plays an important role.
“At the moment, most transmission takes place in homosexual and homosexual sexual networks, and most transmission takes place through sexual or intimate contactsaid Joseph Osmundson, a clinical assistant professor of biology at New York University.
Ogoina says monkeypox mainly spreads among humans through close, skin-to-skin contact, especially with the disease’s signature blister-like rash. Researchers are still investigating whether people can be asymptomatically contagious, but individuals are considered contagious until their rash has completely healed and fresh skin has formed, according to the U.S. Centers for Disease Control and Prevention (CDC).
An investigation into the current outbreak, published in July in the New England Journal of Medicine, found that of the more than 500 monkey pox cases in 16 countries diagnosed in June, 95% were related to sexual activity and 98% were men who have sex with men. In July, WHO Director-General Tedros Adhanom Ghebreyesus advised men who have sex with men to temporarily reduce their number of partners to minimize their risk.
Is monkeypox a sexually transmitted disease (STD)?
Any kind of skin-to-skin contact — not just sexual activity — can potentially spread monkey pox. As a result, monkeypox is not considered a “traditional” STD, according to Dr. Roy Gulick, chief of infectious diseases at Weill Cornell Medicine and NewYork-Presbyterian. The CDC also says that monkeypox is not considered an STD.
Most cases of the current outbreak have been linked to male sexual activity, but Osmundson says the virus can also spread in environments where there is a lot of close non-sexual contact, such as sports teams, spas or dorm rooms.
Can you get monkey pox from surfaces?
It is possible to contract monkeypox from exposure to items, such as clothing or bedding, that have touched an infectious person’s rash. In 2018, a health worker in the UK likely contracted monkey pox after touching a sick person’s bedding, according to an investigation.
But there’s little evidence that “incidental” contact often spreads the virus, says Angela Rasmussen, a virologist at the University of Saskatchewan in Canada. “You have to be exposed to enough virus to actually get infected with it,” she says. That may be possible after sleeping in the same bed or sharing a bath towel with an infectious person, but it’s much less likely after fleeting encounters like touching a shared doorknob, she says.
Since the vast majority of cases so far are related to sexual activity, it’s important to communicate that there is a “spectrum” of risks associated with monkeypox, says Dr. Müge Çevik, a clinical lecturer in infectious diseases at the University of St Andrews in Scotland. “Every single exposure [doesn’t carry equal] risk,” she says. “People really need to know what to look out for. For example, reducing new [sexual] partners can be more helpful than cleaning chairs you sit in a coffee shop.”
Is monkey pox in the air?
It is possible to get monkeypox from exposure to the respiratory fluids of an infectious person, but the WHO says this usually requires close and prolonged personal contact. Researchers are still studying how common that type of transmission is, according to the CDC.
Scientists have shown that under specific experimental conditions it is possible for monkeypox to spread through aerosols, or tiny particles that can linger in the air, but so far there is no strong evidence to suggest that this happens under real-world conditions outside the lab. says Rasmussen. “This mainly spreads in communities of men who have sex with men, and that really suggests that the primary mode of transmission is direct, prolonged skin-to-skin contact,” she says. If airborne transmission were common, she says, we’d probably see many more cases in people from other demographics.
In the shadow of COVID-19, people are understandably concerned about the transmission of monkeypox through aerosols. But “the epidemiology is very different,” Rasmussen says. “These are very different viruses.”
Can children get monkey pox?
More than 80 children around the world have fallen ill with the virus so far, largely as a result of household transmission. A pregnant person can also pass the virus on to their fetus, according to the CDC.
In the 1970s, monkeypox mainly affected young children, but by the 2010s, the virus was more commonly diagnosed in adults, according to a study published in PLOS neglected tropical diseases in February. That’s partly because routine smallpox vaccination (which also protects against monkeypox) ended when smallpox was eradicated, the study authors write. Several decades ago, only small children were young enough to be born after the smallpox vaccination ended. Now a larger part of the population is vulnerable.
Pediatric cases have raised concerns that schools and daycare centers could become hot spots for monkeypox. But Ogoina says that hasn’t happened during the outbreaks in Nigeria, which is a promising sign. “I’m not sure it’s something we should be concerned about,” he says. “But we have to be careful and look for the evidence.”
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