(The Hill) — The Centers for Disease Control and Prevention confirmed a case of monkeypox in a Maryland patient who returned from travel in Nigeria.

The CDC said it is coordinating with international health counterparts, the airline, and state and local health officials in the D.C. area to inform passengers and others who could have come in contact with the infected individual. 

With masks required on the flight due to COVID-19, however, the CDC said scientists think the risk that monkeypox virus spread through respiratory droplets on the plane is “low.” 

Still, the federal agency said it’s “assessing potential risks” among close contacts of the patient both on the flight and after their arrival in the U.S. 

The patient developed mild symptoms, had not been hospitalized, and is in isolation, according to the Maryland Department of Health, which said the individual and any exposed contacts will be monitored for 21 days.

“Our response in close coordination with CDC officials demonstrates the importance of maintaining a strong public health infrastructure,” MDH Deputy Secretary for Public Health Jinlene Chan said in a statement. 

The monkeypox strain identified in the Maryland patient aligns with a version of the virus that has reappeared in Nigeria starting in 2017.

Since the virus’s reemergence, 218 cases have been reported in Nigeria and another eight cases have turned up among international travelers from the country, including one in Texas earlier this year. 

The CDC describes monkeypox as a “rare but potentially serious” disease, noting it starts with flu-like symptoms and lymph node swelling before a rash surfaces across the face and body. The agency called on health care providers to watch for “poxvirus-like lesions” especially among people who traveled to Nigeria and to immediately report suspected cases to authorities.