Current Monkeypox virus may show accelerated evolution as more new cases increase

The monkeypox outbreak that health authorities first noticed in Europe in May is getting worse. According to the latest report from the World Health Organization, there are more than 2,100 confirmed cases and at least one person has died.

Now geneticists finally have enough data to get a handle on exactly how the outbreak started — and where it might go.

It’s not good news. Monkeypox, a viral disease that causes fever and rash and can be fatal in a small percentage of cases, is endemic to Africa. And now it’s running on every other permanently inhabited continent – and evolving quickly. While health officials have all the tools they need to contain it — mainly contact tracing and vaccines — the virus is currently moving faster than us and adapting.

The current strain of monkey pox may have been in circulation, undetected, months before we finally diagnosed the first case outside of Africa. And because there are so many more copies of the virus than we first expected, each mutating individually, this new strain of smallpox could evolve into dangerous new forms at an alarming rate.

“Our data reveal additional evidence of continued viral evolution and possible human adaptation,” wrote a team led by Joana Isidro, a geneticist at the National Institute of Health Dr. Ricardo Jorge in Spain, in the new peer-reviewed study published Friday in naturopathy

A medical lab technician prepares to test suspected monkeypox samples at La Paz Hospital’s microbiology lab.

Pablo Blazquez Dominguez / Getty

Monkeypox first made the jump from monkeys or rodents to humans in the Democratic Republic of the Congo in 1970 — and has flared up frequently in Africa in the decades since. There are two main species, one each in West and Central Africa. The milder West African strain can be fatal in up to 1 percent of cases. The more dangerous Central African strain can kill up to 10 percent of the people it infects.

Smallpox usually spreads through close physical contact, especially sexual contact. To be however, not a sexually transmitted disease. It just takes advantage of the skin-to-skin contact that comes with sex. The virus can also travel short distances with saliva, although probably not far enough to qualify as “airborne.”

Monkeypox occasionally spreads to places where it is not yet endemic. In 2003, 47 people in the US became ill with the West African strain after being exposed to a shipment of pet rodents from Ghana to Texas. A quick response from state and federal health officials — and a few doses of smallpox vaccine, which also works against monkey pox — prevented anyone from dying and temporarily eliminated the virus in the U.S.

Because there are so many more copies of the virus than we first expected, each mutating individually, this new strain of smallpox could evolve into dangerous new forms at an alarming rate.

Officials first noticed the current outbreak, including from the West African tribe, after the diagnosis of a British traveler who returned from Nigeria in early May. Hitchhiking to Europe, the virus quickly spread through physical contact. David Heymann, formerly head of the emergency department at the World Health Organization, said men attending raves in Spain and Belgium “exacerbated” the outbreak — apparently through close, sometimes sexual contact with other men.

After that, the virus accompanied travelers on planes bound for distant lands. Doctors diagnosed the first US case on May 27. As of Thursday, the US Centers for Disease Control had counted about 3,500 cases in 44 countries, including 172 in the US

Only one person has died from smallpox in the current outbreak – in Nigeria. But serious illness and death can be several weeks behind an actual diagnosis, so it’s possible many more deaths will follow.

Worse, on June 3, the CDC announced it had found genetic evidence of American smallpox cases predating the first cases in Europe as of May. Doctors may not have noticed or reported these earlier cases at first because of the similarity between smallpox symptoms and the symptoms of some common sexually transmitted diseases such as herpes.

It has been speculated that the earlier US cases were part of a totally separate outbreak that happened to coincide with the May outbreak. Isidro and her team took 15 samples from current smallpox patients and concluded that, no, there is only one major outbreak. “All the MPX strains sequenced to date cluster closely together, suggesting that the ongoing outbreak has a single origin,” they wrote, using the scientific acronym for monkeypox.

A passenger walks for information about monkey pox virus at Soekarno-Hatta International Airport in Tangerang near Jakarta, Indonesia.

Jepayona Delita / Getty

It’s less clear exactly when the current outbreak has really started. According to Isidro and his company, the virus may have been circulating outside endemic countries long before officials finally noticed the infections and raised the alarm. The virus may have traveled beyond Africa in animals such as pet rodents, spreading from animal to animal before finally jumping to a human host and triggering the current outbreak some time before May, the geneticists wrote.

Most likely, however, monkeypox spread from person to person in the usual way – and recently Isidro’s team concluded. “Current data points for a scenario of more than one introduction from a single origin, with super spreader events (e.g., saunas used for sexual encounters) and overseas travel likely to trigger the rapid global spread.”

In other words, someone – or several people – touched an infected person in Africa, then flew home to Europe or the US and spread the virus to other people through direct contact. The “single origin” is the infected human population in Africa. “More than one introduction” means that multiple travelers picked up the same strain of smallpox and spread it outside of Africa around the same time.

That’s all to say. the May case in the UK was the first infection authorities noticed, but chances are it wasn’t the infection that started the outbreak.

When you start looking for something, you find it.

Michael Wiley, University of Nebraska . Medical Center

One particularly troubling possibility is that smallpox is common or even most common circulating to some extent in non-endemic countries, but we rarely notice it unless there’s a big wave of infections forcing doctors to look more closely at symptoms that could easily be mistaken for something else. Say herpes. “If you look for something, you find it,” Michael Wiley, a public health expert at the University of Nebraska Medical Center who was not involved in the new study, told The Daily Beast.

In any case, undetected or overlapping transmission vectors are alarming — and not just because they could mean faster viral spread to more places before authorities finally, hopefully, contain an outbreak. No, the multiple introductions also provide an opportunity for a virus to mutate more or faster than normal.

When it comes to viral diseases, each infected person is like a living laboratory — a place where the virus can interact with the antibodies and T cells of the human immune system and take countermeasures. The more separate chains of transmission we transmit the smallpox, the more likely the virus will mutate along these vectors in some way that benefits to be named hurts U.S. For example, developing resistance to our vaccines and antibodies.

Isidro’s team found 50 single nucleotide polymorphisms, or SNPs, in the monkeypox strain behind the current outbreak. Each SNP is a change in the baseline DNA of a particular organism. Fifty SNPs “is much more (about 6-12 times more) than you might expect,” the geneticists wrote. “Such an aberrant branch could mean accelerated evolution.”

That doesn’t mean that smallpox itself is learning to evolve faster. It’s possible that the current outbreak just reached some sort of genetic critical mass before we had a chance to intervene. More infected people means more chances to evolve, even if the individual degree of mutation is the same.

“If I had to guess, I think we could see more variance in terms of the number of mutations just based on the size of the outbreak,” James Lawler, an infectious disease expert and a colleague of Wiley at the University of Nebraska Medical Center, told The Daily Beast. “Drift” is just a fancy term for “increase” in this context.

Monkeypox may have been hiding in plain sight long before we finally noticed two months ago. Perhaps this strain of the virus got lucky and more than one traveler spread it outside of Africa almost simultaneously. Maybe it’s evolving faster because it’s getting smarter. It’s more likely to change with its current fast clip because there are so many more copies of the virus than we first expected, and each one mutates every chance it gets.

Either way, it’s all bad news — and it should spark an even greater sense of urgency among health officials as they scramble to diagnose and contain a growing number of cases.

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