Health officials have confirmed the first human case of a flesh-eating screwworm infestation in the United States. The Department of Health and Human Services (HHS) reported on Monday that a patient who recently returned from El Salvador tested positive for New World screwworm (NWS) myiasis. The case was officially confirmed on August 4.
What Is NWS Myiasis?
NWS myiasis is a parasitic infection caused by the larvae—commonly known as maggots—of the New World screwworm fly. These parasites feed on the living tissue of their hosts, making the condition particularly dangerous. While the pest primarily targets livestock, it can occasionally infect humans, especially those with open wounds.
How Authorities Are Responding
The Centers for Disease Control and Prevention (CDC) has collaborated with Maryland’s health department to investigate this rare case. HHS spokesperson Andrew Nixon noted that this marks the first travel-related human case of NWS myiasis in the U.S. linked to an outbreak-affected country.
As per BBC News, the pest, once confined to parts of South America and the Caribbean, has now spread throughout Central America and even reached the U.S. and Mexico, despite efforts to control its movement northward.
Human and Economic Risks
The CDC warns that individuals with open wounds are especially vulnerable to infestation when visiting affected regions or working around livestock in rural areas. Though the risk to public health in the U.S. remains “very low,” the potential consequences are significant.
The USDA’s Animal and Plant Health Inspection Service has joined forces with agriculture agencies, the State Department, and the Food and Agriculture Organization of the United Nations to contain the outbreak. According to the USDA, “When NWS fly larvae burrow into the flesh of a living animal, they cause serious, often deadly damage.” These infestations can affect livestock, pets, wildlife, and, in rare cases, humans.
Economic Impact of a Screwworm Outbreak
A widespread outbreak among livestock could have devastating economic consequences. The USDA estimates that such an event could threaten over $100 billion in economic activity tied to the U.S. cattle and livestock industries.