WHO Says Monkeypox May Have Been Spreading Undetected

A section of skin tissue, harvested from a lesion on the skin of a monkey, that had been infected with monkeypox virus, seen at 50X magnification on day four of rash development in 1968. (CDC/Handout via Reuters)

Officials with the World Health Organization (WHO) say the sudden rise in monkeypox cases worldwide suggests that it has been spreading in an undetected manner for some time.

“We don’t really know whether it’s too late to contain. What WHO and all member states are trying to do is prevent onward spread,” Dr. Rosamund Lewis, the WHO’s monkeypox technical lead, said at a June 1 press conference in Geneva.

The virus, which is generally endemic to certain African countries, may have been transmitted for months or years undetected, Lewis said, according to CNBC. An investigation is ongoing.

WHO Director-General Tedros Adhanom Ghebreyesus said at the same press conference that most monkeypox cases have been reported by homosexual males who sought care at health clinics for sexually transmitted diseases. Monkeypox symptoms generally resolve on their own, although symptoms can be severe in some cases, he said. No deaths have been reported in Europe or North America.

Monkeypox is in the same family as smallpox, which has caused pandemics throughout human history, although officials have said it has milder symptoms.

“Collective immunity in the human population since that time is not what it was at the time of smallpox eradication,” Lewis said. “Anyone under the age of 40 or 50, depending on which country you were born in or where you might have received your vaccine against smallpox, would not now have that protection from that particular vaccine.”

The WHO isn’t currently “recommending mass vaccination” for the virus.

“There is no need for mass vaccination,” Lewis said.

The virus is mainly spreading via homosexual males, she said, noting that it’s important to provide those individuals with the information they need to keep the virus from spreading.

The United States so far has reported about 19 cases in 10 states as of June 1. Most of the cases have been reported in Europe, namely in the UK, Spain, and Portugal.

Last week, the U.S. Centers for Disease Control and Prevention (CDC) revised its travel advisory related to the recent monkeypox outbreak from Level 1 to Level 2.

“Cases of monkeypox have been reported in Europe, North America, and Australia,” the CDC stated. “Some cases were also reported in people who live in the same household as an infected person.”

Initial symptoms include swollen lymph nodes, a chickenpox-like rash, and a fever. U.S. officials have said that the smallpox vaccine can be effective in preventing the spread and transmission of the virus.

The pox-like lesions start out as dark spots on the skin before turning into bumps that fill with fluid. They'll eventually scab over and fall off, possibly leaving people with scars or skin discoloration.