A Maryland resident has tested positive for the state’s first case of a locally acquired strain of malaria in more than 40 years, officials confirmed Friday.

The unnamed person, who was hospitalized and is now recovering, did not recently travel out of the country or to other states with recent locally acquired malaria cases, the Maryland Department of Health said in a statement.

“Malaria was once common in the United States, including in Maryland, but we have not seen a case in Maryland that was not related to travel in over 40 years,” Maryland Department of Health Secretary Laura Herrera Scott said in the statement. “We are taking this very seriously and will work with local and federal health officials to investigate this case.”

Malaria is a mosquito-borne disease caused by a parasite. People with malaria often experience fever, chills, and flu-like illness. Left untreated, they may develop severe complications and die. 

Symptoms usually appear seven to 30 days after an infective bite and include high fever, chills, body aches, diarrhea and vomiting, Maryland health department officials said.

About 2,000 cases of malaria are reported annually nationwide, according to the Centers for Disease Control and Prevention. But he “vast majority” of cases in the country occur in people traveling abroad, the CDC noted. The risk of locally acquired malaria is “extremely low” in the US, according to the agency.

How to protect yourself from malaria

Maryland health department officials recommend these steps to protect yourself from malaria: