Human screwworm case in U.S. traced to person who traveled from Guatemala

A case of infection with the flesh-eating screwworm parasite has been identified in a person in Maryland who had traveled to the United States from Guatemala, according to four sources familiar with the situation.

The person, who received treatment in Maryland, is the first confirmed U.S. case this year of New World screwworm, a parasite that eats cattle and other warm-blooded animals alive, as an outbreak escalates and moves northward from Central America and southern Mexico.

Beth Thompson, South Dakota’s state veterinarian, said Sunday that she was notified of the case within the last week by a person with direct knowledge of the Maryland case.