Rare monkeypox outbreak in U.K., Europe and U.S.: What is it and should we worry?

Monkeypox is a rare but potentially serious viral illness that typically begins with flu-like illness and swelling of the lymph nodes and progresses to a rash on the face and body. Most infections last 2-to-4 weeks.

The virus does not spread easily between people; transmission can occur through contact with body fluids, monkeypox sores, items that have been contaminated with fluids or sores (clothing, bedding, etc.), or through respiratory droplets following prolonged face-to-face contact.

No monkeypox cases have previously been identified in the United States in 2022; Texas and Maryland each reported a case in 2021 in people with recent travel to Nigeria. Since early May 2022, the United Kingdom has identified 9 cases of monkeypox; the first case had recently traveled to Nigeria. None of the other cases have reported recent travel. UK health officials report that the most recent cases in the UK are in men who have sex with men.

Symptoms of the monkeypox virus are shown on a patient's hand, from a 2003 case in the United States. In most instances, the disease causes fever and painful, pus-filled blisters. New cases in the United Kingdom, Spain and Portugal are spreading possibly through sexual contact, which had not previously been linked to monkeypox transmission.

There's a monkeypox outbreak in the United Kingdom, Portugal and Spain. The outbreak is quite small — just 36 suspected cases spread across the three countries, including eight in England and 20 in Portugal. A case in the U.S. has also been reported.

But health officials have little clue where people caught the monkeypox virus. And there's concern the virus may be spreading through the community — undetected — and possibly through a new route of transmission.

"This [outbreak] is rare and unusual," epidemiologist Susan Hopkins, who's the chief medical adviser of the U.K. Health Security Agency (UKHSA), said in a statement on Monday.

"Exactly where and how they [the people] acquired their infections remains under urgent investigation," the agency said in the statement.

Monkeypox can be a nasty illness; it causes fever, body aches, enlarged lymph nodes and eventually "pox," or painful, fluid-filled blisters on the face, hands and feet. One version of monkeypox is quite deadly and kills up to 10% of people infected. The version currently in England is milder. Its fatality rate is less than 1%. A case generally resolves in two to four weeks.

Typically, people catch monkeypox from animals in West Africa or central Africa and import the virus to other countries.

Person-to-person transmission isn't common, as it requires close contact with bodily fluids, such as saliva from coughing or pus from the lesions. So the risk to the general population is low, the U.K. health agency notes.

This contact tracing approach is the most appropriate given the nature and transmission of the virus. The case poses no risk to the public, and the individual is hospitalized and in good condition.

Suspected cases may present with early flu-like symptoms and progress to lesions that may begin on one site on the body and spread to other parts. Illness could be clinically confused with a sexually transmitted infection like syphilis or herpes, or with varicella zoster virus.