The CDC has identified 21 monkeypox cases in 11 US states, and the numbers are expected to rise, officials reported on Friday. Genetic analysis has revealed that while most of the cases appear to be closely related to the outbreak in Europe, two patients have versions of the virus that seem to have evolved from a monkeypox case identified in Texas last year.
Of 17 patients for whom the agency has detailed information, all but one were among men who had sex with men; 14 had travelled to other countries in the three weeks before their symptoms began. Three patients were immunocompromised. CDC researchers have not been able to identify how one patient in an unnamed state acquired the virus. That suggests there is ongoing community transmission at least in that state and possibly others, Dr Jennifer McQuiston of the CDC told reporters.
Monkeypox’s toll worldwide rose sharply this week, to nearly 800 cases as of Friday. The spread of the virus to at least 31 countries outside Africa, where it is endemic, has raised alarm among scientists and public health officials. The US is among the few countries to have stockpiled vaccines and drugs for smallpox as a precaution against its return. Monkeypox is closely related to smallpox, and the vaccines and drugs are expected to be about as effective.