Local health officials have reported that a U.S. citizen with monkeypox escaped from a hospital in a Mexican resort and fled the country.

Monkeypox is a rare but potentially deadly viral illness that begins with flu-like symptoms and lymph node enlargement and proceeds to a rash that covers the face and body.

It is a strain that has been re-emerging from Nigeria since 2017 after 40 years of no documented cases.

Lesions are common in monkeypox patients, so tourists returning from Nigeria should be on the alert for symptoms. The Centers for Disease Control and Prevention (CDC) has recommended clinicians report suspected cases of monkeypox to state or local public health authorities as soon as possible, regardless of whether they are exploring other potential diagnoses.

People can catch monkeypox by coming into contact with sick animals or animal products, such as preparing wild game or being bitten or scratched by an animal, according to the CDC.

The 48-year-old man, originally from Texas, escaped the hospital in Puerto Vallarta on Mexico's Pacific coast last weekend despite medical professionals telling him he should be checked for monkeypox and kept in isolation, according to a statement from the state health department.

The patient arrived at the hospital with symptoms of "cough, chills, muscle pain and pustule-like lesions on his face, neck, and trunk" according to the agency.

There are three stages of monkeypox.

In the third stage, which is a rash, the person's mouth and body develop lesions. The individual will be contagious until all of the scabs have fallen off. The stage takes about three weeks to complete.

The Texan went to the hotel where he was staying with his companion after departing the medical institution and caught a flight out of Puerto Vallarta on June 4 before officials were able to locate him.

On Monday, the US Centers for Disease Control and Prevention informed Mexican authorities that the patient had returned to the US, where a test revealed that he had monkeypox.

Between May 12 and 16, the individual was in Berlin, Germany, and then Dallas, Texas, before arriving in Puerto Vallarta on May 27.

He partied at the Mantamar Beach Club in the resort town of Jalisco during his time in Mexico.

Health officials recommended anybody who visited the club between May 27 and June 4 keep a close eye on their health.

The World Health Organization reported more than 1,000 cases of monkeypox in areas where the illness is not common on Wednesday.