The return of the New World screwworm, a flesh-eating parasite once eradicated from the U.S. in the 1960s, has raised concerns about its potential threat to the nation's food supply.
Unlike other foodborne diseases, experts say the screwworm is not a threat to the food on our dinner tables. "The US food supply is not compromised by New World screwworm, which is an animal issue, but not a foodborne pathogen issue," said Dr. Aaron Glatt, chief of infectious diseases at Mount Sinai South Nassau Hospital.
Screwworms die off during standard meat processing and cooking, and the US food supply is regularly tested by regulatory agencies to ensure food safety and humane handling requirements are met.
The USDA has reported 33 screwworm infections in animals in Texas and New Mexico since early June, including cattle, goats, and a pet dog. However, Dr. Glatt emphasized that the screwworm does not result in meat, milk, or produce becoming contaminated.
A screwworm is a fly that infects warm-blooded animals, usually livestock, wildlife, and pets. Infection starts when a female fly lays eggs in a wound, which can be as small as the size of a tick bite. The eggs hatch into maggots that "screw" into the wound to feed.
Experts warn that climate warming could expand the areas where the insect can survive, but the current outbreak has been driven primarily by its northward spread through Central America and Mexico. The USDA is combating current U.S. outbreaks by deploying sterile male flies to mate with female flies.
Researchers warn that in rare cases, human infection can occur, prompting symptoms such as a non-healing wound with pain, redness and swelling that is getting worse, a sensation of movement or crawling in the wound, and visible fly larvae in the wound.
To protect against infection, the CDC recommends following certain steps, including containing any maggots that fall to the ground and contacting a doctor to safely remove the remaining maggots.
