Second monkeypox strain found in US cases

NEW YORK CITY: A genetic analysis of recent monkeypox cases suggests there are two distinct strains in the United States, health officials said on Friday (Saturday in Manila), raising the possibility that the virus has been circulating undetected for some time.

Many of the US cases were caused by the same strain as recent cases in Europe, but a few samples show a different strain, federal health officials said. Each strain had been seen in US cases last year, before the recent international outbreak was identified.

Analysis from many more patients will be needed to determine how long monkeypox has been circulating in the US and elsewhere, said Jennifer McQuiston of the Centers for Disease Control and Prevention (CDC).

"I think it's certainly possible that there could have been monkeypox cases in the United States that went under the radar previously, but not to any great degree," she told reporters.

However, she added, "there could be a community-level transmission that is happening" in parts of the US where the virus is yet to be identified.

The CDC said it was trying to increase its work on finding infections, and it was likely more cases would be reported.

The findings mean the outbreak is likely to be difficult to contain, said Dr. Angela Rasmussen, a virologist at the University of Saskatchewan in Canada.

It's not clear how long infections have been happening, and where. Some infections may have been misdiagnosed as something else.

"We don't really have a good sense of how many cases are out there," Rasmussen said.

Monkeypox is endemic in western and central Africa, where people have been infected through bites from rodents or small animals. It does not usually spread easily among people.

But last month, cases began emerging in Europe and the US. Many — but not all — of those who contracted the virus had traveled overseas, and health officials in a growing number of countries are investigating.

As of Friday, the US has identified at least 20 cases in 11 states. Hundreds of other cases have been found in other countries, many apparently tied to sexual activity at two recent raves in Europe.

So far, many of the reported cases outside Africa have been in men who have sex with men, but health officials stress that anyone can get monkeypox. One heterosexual woman is among the US cases under investigation, officials said.

The illness typically begins with flu-like symptoms and swelling of the lymph nodes, followed by a rash on the face and body.

No death from monkeypox has been reported in the US or Europe so far. But that could change if infections start occurring in more vulnerable people, like very young children or people with weakened immune systems, Rasmussen said.

She raised another concern: even if outbreaks among people are contained, it's possible the virus could take hold in the US rodent population, either through pets or unwelcome rats in homes.

"It's not out of the question," Rasmussen said.

Also on Friday, the CDC published an analysis of 17 of the first reported US cases. The average age was 40, and all but one identified themselves as men who have sex with men. Fourteen had traveled internationally to 11 different countries, according to the report.

Source: TheManila Times