Draft Genome Sequence of Latest Monkeypox Virus Unveiled

The latest monkeypox virus now popping up in multiple countries appears most closely related to a strain that circulated in 2018-2019, according to a draft genome sequence of a recent case.

Sequencing of a skin lesion sample from an infected male patient in Portugal -- where at least 20 confirmed cases have been reported -- suggests the latest monkeypox virus belongs to the West African clade. It is most closely related to cases that spread from Nigeria to the U.K., Israel, and Singapore in 2018 and 2019, reported João Paulo Gomes, PhD, of the National Health Institute Doutor Ricardo Jorge in Lisbon, and colleagues.

The group, who published their findings on the preprint server virological.org, said the draft genome sequence "will certainly contribute to better understand the epidemiology, sources of infection, and transmission patterns."

Experts told MedPage Today there's nothing that stands out as alarming from the draft sequence.

"So far, the sequencing has not indicated that the virus is substantially different from the others that we know of," said Grant McFadden, PhD, of the Biodesign Center for Immunotherapy, Vaccines and Virotherapy at Arizona State University.

William Schaffner, MD, of Vanderbilt University in Nashville, Tennessee, told MedPage Today that this preliminary sequence suggesting the new strain is from the West African monkeypox family "fits in nicely with early epidemiologic information."

"We already had some epidemiologic information that it was likely that someone either from or visiting Nigeria might well have been the person who transmitted the monkey pox to Europe," he said.

Over the last month, monkeypox has spread to multiple countries where in past years it rarely showed up, leading researchers to wonder whether a more transmissible strain has emerged. The U.K., Spain, Portugal, France, Canada, Sweden, and Italy all have confirmed or suspected cases.

Most recently, monkeypox was detected in the U.S. in a Massachusetts individual who had traveled to Canada; a possible New York City case is under investigation as well.

Monkeypox is endemic in the Democratic Republic of the Congo and across some Central and West African countries, and spreads through direct or indirect contact with animals. Human-to-human transmission is thought to primarily occur through large respiratory droplets, but other means include direct contact with body fluids or lesions, and contact with fomites.

The illness usually begins with flu-like symptoms and lymph node swelling, followed by a rash on the face and body. The West African strain, confirmed in the U.K., has a fatality rate of around 1%.

Experts stressed that there is not yet reason to be overly worried. "This is not, and I emphasize 'NOT' in capital letters, a highly transmissible virus," said Schaffner.

"This is a virus that requires very close -- usually hands-on -- contact with someone else, or else prolonged, very close face-to-face contact with someone," he said. "This is not to be confused with COVID and the way COVID spreads."

CDC has suggested that many of the recent monkeypox cases have spread via sexual contact, and have stated that "cases include individuals who self-identify as men who have sex with men," although this does not mean it would be limited to them. But if sexual contact indeed turns out to be the cause of many of the new cases, "there's fairly good reasons to believe it can be snuffed out," said McFadden.

"We will learn a lot more in the next couple of weeks," he added. "But it's not really something that's worrying. There's a good vaccine, there's good drugs against viruses in this family."

Schaffner added that with the fast turnaround on sequencing in this day and age, experts can begin to understand outbreaks like the current one far sooner. "Look at how rapidly science can get a genome and sequence a new pathogen. It's just a matter of days," he said. "Scientifically, and from the public health point of view, that's very exciting."

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