According to A.P., New York state health officials said late Friday that a New York City resident tested positive for the virus that causes monkeypox.
Why it matters: It's the state's first confirmed case of monkeypox since multiple countries recently reported infections from the virus, which previously had been rarely seen outside of western and central African countries.
It's also the U.S.' second confirmed monkeypox infection this year, as Massachusetts reported the first on Wednesday.
The unidentified patient is being treated and isolated. At the same time, according to A.P., the state determines how the person was infected and reaches people who may have contact with the person.
The state is also awaiting final confirmation from the Centers for Disease Control and Prevention.
The New York City Department of Health said Thursday it was investigating at least one possible case of monkeypox.
The big picture: Numerous other countries reported multiple confirmed and possible cases this week, including Australia, Canada, Belgium, Italy, London, Northern Ireland, Portugal, and Spain.
Monkeypox has two main types related to smallpox: the West African clade, with a fatality rate of around 1%, and the Congo Basin (Central African) clade, with approximately 10%, Axios' Eileen Drage O'Reilly reports.
The current circulating virus strain appears to be the milder West African type that often starts with flu-like symptoms and swelling lymph nodes, progressing to a blistering rash.
The smallpox vaccine is believed to be effective against monkeypox.
The CDC warned Friday that doctors and state health departments in the U.S. should look for possible cases, explicitly looking for the characteristic rash associated with the virus.
The World Health Organization's European chief also said he is concerned that monkeypox could spread in Europe in the next few months as people gather for parties and festivals during the summer.
Saturday, the World Health Organization (WHO) called a Strategic and Technical Advisory Group meeting on Infectious Hazards with Pandemic and Epidemic Potential (STAG-IH) to discuss the case clusters.
"Monkeypox has so far been reported from 11 countries that normally don't have the disease. WHO is working with these countries & others to expand surveillance, and provide guidance. There are about 80 confirmed cases, and 50 pending investigations. More likely to be reported," WHO tweeted today.
Before the current outbreak, the largest monkeypox outbreaks outside of West and Central Africa occurred in six U.S. states: Illinois, Indiana, Kansas, Missouri, Ohio, and Wisconsin, in 2003, when 47 cases were recorded with a link to infected pet prairie dogs.