Monkeypox has been circulating among humans since 2016, according to a new study. This discovery represents a paradigm shift, wrote a research team with Swiss participation in the study published Thursday in “Science”. “The origin of the surprising 2022 outbreak was a long time ago,” said study co-author Richard Neher of the University of Basel.
Until recently, monkeypox was considered a zoonosis, a disease transmitted from animals to humans, as the international research team wrote in the study. The first cases of monkeypox in humans were discovered in the 1970s. Subsequently, most cases of the disease were considered to be isolated transmissions, so-called rebound events, with only a few people affected in the human population.
Transmission also from person to person
That changed in 2022, researchers said. The fact that monkeypox suddenly appeared outside countries where infected animals were known indicated that the spread of the virus was no longer just a zoonotic infection.
The research team has now analyzed genetic sequences from the 2018 and 2022 monkeypox viruses. The researchers found that the DNA sequences differed more than would be expected.
According to the study, most of these mutations are changes in the building blocks of the genome that are due to the activity of a human immune system defense enzyme called APOBEC3. According to researchers, this suggests that the monkeypox virus is spreading throughout the human population, rather than just sporadically jumping from animals to people. Based on the rate of mutations per year, the research team estimated that the newest strain of monkeypox virus has been circulating in the human population since at least 2016.
“But there is no evidence that these mutations have significantly altered the virus,” says Neher. There is no evidence that this changed the transmissibility of the virus.
Service: Specialized article DOI number: 10.1126/science.adg8116