Screwworm Is Back in the U.S. for the First Time in 60 Years. The Agency That Kept It Out Lost 25% of Its Staff.

New World screwworm, a flesh-eating parasite that burrows into the wounds of living animals, has been confirmed in U.S. livestock for the first time since the 1960s. Five cases in Texas across three counties. One reclassified case in Lea County, New Mexico. The pest spread from the border to the Hill Country — 90 miles inland — in five days.

The United States spent 40 years and more than $750 million eradicating screwworm through the sterile insect technique. The program worked. It kept screwworm out of the country for six decades. The agency that ran it just lost a quarter of its workforce.

APHIS Lost 25% of Its Workforce Before the Outbreak

APHIS, the Animal and Plant Health Inspection Service, is the federal agency responsible for keeping foreign animal diseases out of U.S. livestock. Between February and April 2025, APHIS lost 2,105 employees — 25% of its workforce — through DOGE-driven resignation agreements. Texas alone lost 248 APHIS employees.

In late January 2025, the administration issued stop-work orders on the FAO Global Health Security Program — the main U.S.-funded program that monitored screwworm in Central America. By March, termination orders followed. The program cost $250 million, was 90% U.S.-funded, operated in 49 countries, and had supported 180+ outbreak investigations in 22 countries in 2024 alone.

FAO itself credited the program with “monitoring and responding to New World Screwworm throughout Central America, preventing the spread of the disease to the U.S.” After funding was withdrawn, the screwworm barrier at the Darién Gap in Panama broke down. Thousands of cases emerged across Panama, Costa Rica, Nicaragua, Honduras, and Mexico.

How Screwworm Reached Texas

Screwworm reappeared in Panama and Costa Rica in 2023. It moved through Central America into Mexico by late 2024. The international monitoring programs that would have tracked and contained that movement were defunded in early 2025.

By mid-2025, screwworm reached the U.S.-Mexico border. On June 3, 2026, USDA confirmed the first U.S. case in a calf in Zavala County, Texas.

The U.S. Produces 100 Million Sterile Flies. It Needs 600 Million.

Screwworm eradication depends on flooding an area with sterile male flies that mate with wild females and produce no offspring. USDA Secretary Brooke Rollins says the current outbreak requires roughly 400 million sterile flies per week. Past eradication efforts needed 500 million. The response team says up to 600 million.

The sole remaining production facility, in Panama, produces 100 million per week. USDA completed a sterile fly dispersal facility at Moore Air Base in Edinburg, Texas in February 2026 and broke ground on a production facility at the same site in April. That production facility will not begin operating until November 2027 — 100 million per week initially, scaling to 300 million.

A converted facility in Metapa, Mexico is expected to add 60-100 million per week by summer 2026. Even when all facilities are operational, combined capacity reaches roughly 500 million per week — short of the 600 million the response team says is needed now.

USDA has deployed $165 million in emergency funding (December 2024) and a $100 million Grand Challenge for enhanced sterile fly production (January 2026). The money is flowing. But emergency spending does not replace the staffing and monitoring infrastructure that was dismantled.

Federal and State Response

USDA Secretary Rollins announced a five-part response: quarantine zones, sterile fly releases, expanded trapping, wildlife surveillance, and border inspections. Governor Abbott issued a disaster proclamation and activated state resources. Texas Agriculture Commissioner Sid Miller called the federal response “slow, bureaucratic, and incomplete.”

HHS Secretary Robert F. Kennedy Jr. issued an emergency declaration allowing FDA to authorize animal drugs against screwworm. Kennedy said the move would “equip FDA to act quickly, limit the spread of New World screwworm and protect America’s livestock.”

The congressional district where the outbreak started — TX-23 — is currently vacant. The ranchers in the quarantine zone have no House representative to call.

$1.8 Billion in Livestock Losses, $100 Billion at Risk

A 1976 Texas screwworm outbreak cost $732 million in direct losses and $1.8 billion in total economic impact (inflation-adjusted). A full re-establishment could jeopardize $100 billion in national cattle and livestock activity.

Markets are already reacting. Live cattle futures fell $5.40 after the additional cases were confirmed June 8. Feeder cattle dropped 4.94% over the past month.

Canada has banned livestock imports from Texas. Florida issued emergency livestock rules. Georgia, Tennessee, and Montana have implemented additional veterinary requirements.

Screwworm Infects Humans Through Any Open Wound

Screwworm is not just a livestock problem. Female flies lay eggs in any open wound on a warm-blooded animal, including humans. A small cut, a tick bite, a surgical incision, even a scratch is enough. Larvae hatch within 24 hours and burrow into living tissue, feeding on flesh and creating wounds that expand rapidly.

Untreated screwworm myiasis can kill within a week. Infants, elderly people, and anyone with compromised immune systems face the highest risk. When treated early, the condition is not fatal — but it requires medical intervention to remove larvae and treat the wound.

Mexico has confirmed 76 human cases by early 2026, with at least one death. Costa Rica has reported seven deaths since the pest returned in 2023. Mexico’s total animal cases exceeded 6,700 by September 2025, growing 32% month over month. One travel-associated human case was confirmed in the U.S. in August 2025.

The CDC says U.S. human risk is currently low but recommends anyone in affected areas who notices a wound that is not healing or appears to contain larvae seek immediate medical care. New Mexico has issued a health alert to providers and veterinarians to report suspect cases immediately.

What You Can Do

Contact your U.S. Senators. Ask them to cosponsor and pass the bipartisan STOP Screwworms Act (S. 1751 / H.R. 3392). The bill authorizes $300 million for a domestic sterile fly production facility and requires USDA to begin construction within 180 days. It was introduced May 2025 by Senators Cornyn (R-TX), Cruz (R-TX), Lujan (D-NM), Heinrich (D-NM), and Hyde-Smith (R-MS). It has not had a hearing in either chamber. USDA is already building a facility using existing authority, but without legislation, that funding can be cut again. The bill makes it permanent.
Contact your U.S. Representative. H.R. 3392 is stalled in the House Agriculture Committee, which has been focused on the farm bill. Chairman Thompson has urged USDA to act under existing authority instead of waiting for the STOP Act, but existing authority did not prevent the 25% staffing cut. Ask your representative to push for a hearing and demand emergency supplemental funding to restore APHIS staffing and the international monitoring programs terminated in March 2025.
If you are a livestock producer in Texas or New Mexico, report any animal with a suspicious wound to the USDA screwworm hotline at 1-800-USDA-TAG (1-800-873-2824) or your state veterinarian. Texas Animal Health Commission has current quarantine zone maps.