A genetic analysis has found there may be two strains of monkeypox circulating in the US, according to the Associated Press.
Monkeypox, which is endemic to Central and West Africa and spreads through close contact, has been detected recently outside of those regions, including in the UK, Portugal, and the US. As of Friday, the AP notes that about 20 monkeypox cases have been detected in the US.
The agency also announced, the AP says, that most of the monkeypox cases in the US appear to be the same strain that has also recently been identified in European cases, but a few seem to be due to different strains. It adds, though, that those strains have previously been seen in the US in a few cases from 2021, before the current international outbreak. This, it notes, suggests there could have been some low-level circulating of the virus in the US, but the Centers for Disease Control and Prevention's Jennifer McQuiston says more analysis is needed.
"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 says, according to the AP.