As monkeypox cases continue to rise around the world, U.S. health officials have urged clinicians to stay vigilant for potential monkeypox cases—a call echoed by President Joe Biden on Sunday.

Monkeypox is in the US. Here's what you need to know.

What is monkeypox?

Monkeypox is a rare viral infection that begins with flu-like symptoms and progresses to a distinctive rash on the face and body. Most infections resolve within weeks, but some cases can be fatal, according to the World Health Organization (WHO).

Humans can catch monkeypox through contact with infected animals or animal products. Human-to-human transmission, meanwhile, can occur via contact with bodily fluid, sores, or items contaminated by bodily fluid, but most often occurs via large respiratory droplets, which rarely travel more than a few feet.

Typically, symptoms of monkeypox are mild, including headaches, muscle pain, chills, and swollen lymph nodes. Patients can also develop rashes on their face and body that then turn into skin lesions that eventually fall off.

Monkeypox cases are on the rise globally

Monkeypox cases have been popping up recently around the world. According to the Washington Post, WHO has identified monkeypox cases in at least a dozen countries where the disease is not typically endemic. While monkeypox is usually found in Central and West Africa, cases have recently been reported in several European nations, the United States, Australia, and Canada.

Canadian health officials in Montreal last week confirmed they found evidence of a connection between the first U.S. case and some of their suspected cases. According to STAT News, most of the cases in Montreal were in men in their 30s to 50s.

Notably, British officials last week said that four of the nine cases it identified were among men who have sex with men, suggesting that the virus could be spreading through sexual contact. As of Friday, European health officials had confirmed over 70 cases of monkeypox across the continent, the Post reports.

Generally, monkeypox cases are very rare in the United States, however two cases were reported in the United States last year—one in Texas and one in Maryland.

Last week, the Massachusetts Department of Public Health reported the first confirmed case of monkeypox in the United States this year in a man who had recently traveled to Canada.

New York state health officials late Friday night confirmed that a New York City resident tested positive for the virus that causes monkeypox as well, according to the Associated Press. In addition, the Florida Department of Health on Saturday reported that state health officials and CDC are investigating a potential case in Broward County.

According to the Post, federal officials are anticipating a rise in cases in the coming days.

Officials urge caution

On Friday, CDC issued an alert encouraging doctors and state health departments to remain vigilant for potential monkeypox cases. In particular, CDC said that clinicians "should be vigilant to the characteristic rash associated with monkeypox."

According to the alert, doctors should suspect monkeypox if a patient develops a rash after traveling to countries with confirmed cases, or if a patient has reported having contact with anyone else who has recently traveled to one of those countries.

In addition, CDC added that doctors should suspect monkeypox if a symptomatic patient "is a man who regularly has close or intimate in-person contact with other men, including those met through an online website, digital application ('app'), or at a bar or party."

Separately, President Biden on Sunday said that the recent spread of monkeypox is "something that everybody should be concerned about."

"It is a concern in that if it were to spread it would be consequential," Biden added.

According to National Security Advisor Jake Sullivan, the president has been receiving regular updates from his health team on the outbreaks. Currently, the United States has vaccines "available to be deployed," Sullivan said.

Notably, the smallpox vaccine works for monkeypox. When asked whether the U.S. has enough stockpile of the smallpox vaccine to control the spread of monkeypox, Biden said, "I think we do have enough to deal with the likelihood of a problem."

On Monday, President Biden sought to calm concerns about the recent rise in monkeypox cases in Europe and the United States. He said he did not see the need to implement any strict quarantine measures to prevent the spread of the disease.

Just one day after he said the virus was something "to be concerned about," Biden said, "I just don't think it rises to the level of the kind of concern that existed with COVID-19[.]" (Knutson, Axios, 5/21; Goldstein, New York Times, 5/19; Scribner, Axios, 5/20; Taylor et al., Washington Post, 5/20; Saric, Axios, 5/22; Nirappil, Washington Post, 5/20; Joseph, STAT News, 5/19; AP/Modern Healthcare, 5/22; Samuels, The Hill, 5/23; Axios, 5/22; Putka, MedPage Today, 5/23; Kim, Washington Post, 5/23)