Health officials have confirmed the first human case of flesh-eating screwworm in the United States. The infection was identified in a person who recently returned from El Salvador, according to the Department of Health and Human Services. The case was confirmed on Aug. 24 and is believed to be linked to international travel.
The condition, known as New World screwworm myiasis, occurs when fly larvae infest open wounds and feed on living tissue. It primarily affects livestock but can also pose a risk to humans under specific conditions.
The Centers for Disease Control and Prevention worked with Maryland’s health department to investigate the incident. Health and Human Services spokesperson Andrew Nixon said this was the first travel-related case involving the flesh-eating screwworm reported in the U.S.
Parasite’s spread and human risk
The parasite is most common in South America and the Caribbean. Despite efforts to prevent its spread, it has now reached every country in Central America, including Mexico.
Health authorities said the threat to public health in the U.S. remains low. However, individuals with open wounds who travel to rural areas where livestock are present may face higher risks. The parasite targets warm-blooded animals but can occasionally infect humans.
The U.S. Department of Agriculture is working with other government agencies, the State Department, and the Food and Agriculture Organization of the United Nations to address the wider outbreak. Their focus is on limiting the parasite’s spread and protecting livestock populations.
Economic risk and ongoing surveillance
According to the USDA, the larvae of the screwworm fly burrow into the flesh of living animals, causing severe injury or death if left untreated. While rare in people, infestations can also affect pets, wildlife, and birds.
Officials warned that a widespread outbreak in the U.S. livestock industry could lead to serious economic losses. The USDA estimates that more than $100 billion in economic activity tied to cattle and related industries could be at risk if the parasite spreads domestically.
The agency continues to monitor potential threats and urges travelers and veterinarians to report any signs of infection promptly.
