New World screwworm is disgusting. How could it not be a food safety issue?

New World Screwworm Is Disgusting. How Could It Not Be a Food Safety Issue?

A Threat to Livestock, Not Human Consumers

New World screwworm is disgusting How could – In June 2026, the New World screwworm made a surprising return to the United States, marking its first presence in the country in decades. This flesh-eating fly has a reputation for targeting livestock, particularly cattle, as its primary hosts. While the sight of larvae burrowing into animal flesh might unsettle meat-eaters, public health officials have repeatedly reassured the public that the parasite does not pose a direct risk to food safety. However, its impact on the agricultural sector is significant, with potential economic consequences stretching into the billions, as highlighted by the Dallas Federal Reserve.

The New World screwworm’s presence raises concerns about rising beef prices, especially during a period when consumers are already facing record-high costs for popular cuts like burgers and steak. Yet, unlike bacteria such as salmonella or viruses like hepatitis A, which can infiltrate the food supply unnoticed, the screwworm is unlikely to reach human plates. According to Maximillian Seunik, executive director of the Screwworm Free Future nonprofit, the parasite’s threat lies in its economic effects rather than compromising food quality. “It’s a threat to food, inasmuch as it’s a threat to food prices, but it’s not a threat from the perspective of food quality or the food that you’ll be consuming,” Seunik said.

Unique Biology Keeps Screwworms Out of the Food Chain

The New World screwworm stands out among its fly relatives due to its specific dietary needs. While many fly species feed on decaying matter, these larvae require living tissue to survive and develop. This distinction means that screwworm flies don’t lay eggs in raw meat, fruits, or vegetables. Instead, they target mucous membranes or open wounds—such as those from a tick bite—on warm-blooded animals, including occasionally humans. Once the eggs hatch, the larvae immediately begin consuming the animal’s flesh, deepening the wound as they grow.

One of the key reasons the screwworm doesn’t enter the food supply is its inability to survive on nonliving material. If the host animal dies before the larvae complete their life cycle, the larvae typically perish alongside it. This biological limitation ensures that infested animals are unlikely to reach slaughterhouses, as they would appear visibly compromised. Dr. Jonathan Cammack, a livestock entomology and parasitology expert at Oklahoma State University, explained, “Meat is still safe. It’s not even a true disease like what we think of with a bacteria or virus that spreads from animal to animal. So if a single animal in a herd is infested, that doesn’t mean the entire group will be affected.”

Strict Safeguards Prevent Contamination

The U.S. Department of Agriculture’s rigorous meat inspection system acts as a final barrier against screwworm contamination. Even if an animal is infested, the process of slaughtering and inspecting meat ensures that infected individuals are identified, isolated, and given special attention. Animals deemed unfit for human consumption due to a screwworm infestation would be labeled as US Suspect, requiring further examination by a public health veterinarian. If the vet confirms the animal is unsuitable, it would not enter the food supply.

Additionally, the U.S. Food and Drug Administration mandates that animals treated with medications be kept out of the food chain for a specific period, depending on the drug used. This regulation prevents harmful residues from ending up in meat, further safeguarding consumers. While these measures are robust, they rely on early detection and proper handling of infested animals. Cammack emphasized that the process is designed to catch any anomalies, ensuring that meat remains free from contamination.

Organized Crime and the Spread of Screwworms

The screwworm’s resurgence in the U.S. is linked to a complex web of factors, with organized crime playing a notable role in its spread. Reports suggest that smuggled infected livestock or contaminated materials may have contributed to the parasite’s reestablishment in the southwestern region. This human-driven introduction underscores the importance of vigilance in agricultural practices. Despite its alarming presence, the screwworm remains a manageable threat, thanks to the country’s existing food safety protocols.

Even in wildlife, the screwworm’s impact is limited. Hunters who encounter an infested animal can easily recognize the signs—visible wounds, cream-colored maggots, and a distinctive, pungent odor. These indicators make it unlikely that hunters would consume such meat without first inspecting it. If an animal does reach a game processor, the professional would typically discard it, ensuring it doesn’t make it to the market. “If hunters come across an infested animal, the USDA encourages them to report it,” said the article, highlighting the collaborative effort between regulators and industry players to maintain food safety.

Conclusion: A Disgusting but Controllable Threat

Although the New World screwworm’s presence in the U.S. is a concerning development, its biology and the nation’s food safety infrastructure minimize the risk to human health. The parasite’s reliance on live tissue and its visible effects on animals create natural checkpoints in the supply chain. While the economic impact is substantial, particularly for the livestock industry, the safeguards in place ensure that consumers remain protected. As the parasite continues to spread, ongoing efforts by public health agencies and agricultural experts will be critical in preventing a larger crisis. For now, the meat on our plates is safe, and the threat of the screwworm is more about price than quality.