New monkeypox cases in U.S., Europe have health officials concerned

LOS ANGELES — An increase in the number of cases of monkeypox, a rare but potentially serious viral illness, in Europe and a single case in Massachusetts is attracting increased attention from health officials.

While monkeypox is in the same family of viruses as smallpox, it has been nowhere nearly as contagious as its better-known cousin, nor is it anywhere nearly as contagious as the virus that causes COVID19.

Monkeypox is garnering increased attention because outbreaks and cases are showing up in areas where they don’t usually occur, raising questions about whether there’s an increased chance for human-to-human transmission.

Monkeypox causes symptoms similar to smallpox, but they are generally milder. The illness begins with fever, aches, swollen lymph nodes, chills and exhaustion, and then later develops into a rash, usually starting on the face and then spreading to other parts of the bodies, turning into pusfilled sores before they fall off.

The illness can last two to four weeks. According to the World Health Organization, historically, between 0% and 11% of those with monkeypox infections have died from the disease, with the fatality rate higher among younger children.

The last major monkeypox outbreak in the U.S. occurred in 2003, leading to 71 confirmed or suspected cases — mostly in Wisconsin, Indiana and Illinois. The confirmed cases had contact with pet prairie dogs obtained from an animal distributor in suburban Chicago that had been housed near Gambian giant rats and dormice that came from Ghana.

No one died in this U.S. outbreak. Only two patients — both children — had serious illness; both recovered.

The 2003 outbreak was the first time monkeypox had been detected in the U.S.

It usually takes seven to 14 days after exposure for the onset of symptoms, but it can take as long as 21 days before symptoms appear.

There are tools available to control monkeypox outbreaks, the CDC said, including use of the smallpox vaccine, which is not available to the general public. One vaccine has been licensed for use in the U.S. to prevent monkeypox and smallpox. “Past data from Africa suggests that smallpox vaccine is at least 85% effective in preventing monkeypox,” the CDC said.

“In the event of another outbreak of monkeypox in the U.S., CDC will establish guidelines explaining who should be vaccinated,” the CDC said. Smallpox is the only infectious disease that targets humans that has been declared eradicated.

People are usually exposed to the monkeypox virus through bites or scratches from infected animals, Ferrer said.