Three weeks have passed since public-health authorities in the United Kingdom confirmed a case of monkeypox. More than 400 confirmed or suspected cases have emerged in at least 20 non-African nations, including Canada, Portugal, Spain and the United Kingdom, the largest outbreak ever seen outside Africa. There is no obvious link between many of the clusters, raising the possibility of undetected local transmission of the monkeypox virus.
There is still a lot to be learned, but we need to act quickly and decisively, says Anne Rimoin, an epidemiologist at the University of California, Los Angeles.
Nature outlines some of the questions that researchers are trying to answer.
Researchers have been analyzing the genomes of people with monkeypox in countries including Belgium, France, Germany, Portugal and the United States. The most important insight they have gained so far is that each sequence closely resembles a monkeypox strain found in West Africa. The strain has a death rate of less than 1% in poor, rural populations, making it much less lethal than another strain that has been found in Central Africa. There is a fatality rate of up to 10%.
There are clues about how the outbreak might have started. Researchers need more data to confirm their suspicions, but the sequence they have evaluated so far is nearly identical, suggesting that a thorough epidemiological investigation might find that the recent outbreaks outside Africa all link back to a single case.
The current sequence is similar to the ones from a number of monkeypox cases that were linked to travel in West Africa. The simplest explanation is that the person who had the first non-African case this year was bitten by an animal while visiting a similar part of Africa.
The Icahn School of Medicine at Mount Sinai in New York City has a virologist who says other explanations can't be ruled out. It is1-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-6556 This hypothesis is less likely because monkeypox can cause visible lesions on people's bodies, which would probably be brought to the attention of a physician.
The spread of the poxviruses outside Africa will be difficult to understand, says a researcher who studies poxviruses. Researchers are still trying to figure out which genes are responsible for the higher virulence and transmissibility of the Central African strain compared with the West African one more than 17 years after they identified a difference between the two.
There are many mysteries in the poxviruses genomes. The genome of the monkeypox is six times larger than that of the coronaviruses. The monkeypox genomes are six times harder to analyse than their cousins, says Rachel Roper, a virologist at East Carolina University.
Palacios says that there is a lack of resources dedicated to genomic-surveillance efforts in Africa, where monkeypox has been a public-health concern for many years. He says that virologists are in the dark because they don't have a lot of monkeypox sequence to compare. Scientists have warned funding agencies for more than a decade that there could be more monkeypox outbreaks.
The head of the Nigeria Centre for Disease Control, Ifedayo Adetifa, says that African virologists have been frustrated by the lack of funding for studies about monkeypox.
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It would be useful to sequence the virus in animals to understand how it evolved. The virus is known to cause disease in animals such as rodents, but scientists have yet to find its natural home in Africa.
The spread of the poxviruses outside Africa will be difficult to understand, says a researcher who studies poxviruses. Researchers are still trying to figure out which genes are responsible for the higher virulence and transmissibility of the Central African strain compared with the West African one more than 17 years after they identified a difference between the two.
If deployed, the vaccines would be used to inoculate people against the disease. The CDC is not yet using a strategy for the poxviruses, according to the epidemiologist who heads the team. According to CNN, the United States plans to give vaccine to health-care workers treating people who have been exposed to the disease. It might be worth considering vaccinating groups at a higher risk of infections, in addition to close contacts of people who have been exposed to infections.
Even if public-health officials can stop the transmission of monkeypox in humans, they are concerned that the virus could return to animals. In countries that don't have any known animal reservoirs of the virus, the chances of it being transmitted to people again and again would increase. The European Centre for Disease Prevention and Control highlighted this possibility, but found the probability very low. European health officials strongly recommended that pet rodents such as hamsters and guinea pigs be isolated and monitored in government facilities or euthanized to avoid the possibility of spillover from people with confirmed cases of monkeypox.
Although the risk is low, Moss says the main concern is that scientists wouldn't know if a spillover event occurred until it was too late.
The Monkeypox virus can be spread through close contact with bodily fluids and respiratory droplets. According to the Associated Press, health officials are looking at sexual activity at raves in Spain and Belgium as a possible cause of monkeypox transmission.
The linking of cases to sexual activity doesn't mean that the virus is more contagious or is transmitted sexually, but just that the virus spreads readily through close contact, Rimoin says. Roper says that poxviruses can survive for a long time outside the body, making surfaces such as bedsheets and doorknobs potential destinations of transmission.
Although health officials have noted that many cases have been among men who have sex with men, Rimoin emphasizes that the most likely explanation is that the virus was introduced into the community.
The new attention on monkeypox has laid bare how little scientists know about the disease.
The article was first published in May of 2022.
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