New World Screwworm Cases Reach Five With Detection in New Mexico

Three more cases of the New World screwworm have been confirmed, including one outside the main cluster in Texas, the U.S. Department of Agriculture announced Monday. The screwworm is a fly larva that eats living flesh. The flies lay eggs in open wounds of cattle, wildlife, pets, and occasionally humans.

So far, five confirmed cases include three calves and a goat in Texas and a dog from Lea County, New Mexico. The dog, initially reported as a Texas case, was reclassified after officials determined it had not traveled outside New Mexico. Officials have set up 12-mile quarantine zones around each case site.

New Mexico authorities said they will increase animal inspections if infected flies are found near the property.

The government breeds sterile male flies and releases them from planes to mate with wild females, a method used for decades to contain the pest at the southern end of Panama. The U.S. Department of Agriculture has been dropping sterile flies in south Texas since February and is expanding production capacity.

A $750 million fly factory is planned in Texas. Officials said the long-term goal is to have enough sterile flies to prevent reappearance after winter reduces fly populations in 2027. Texas officials have opened a 24-hour hotline and online map for reported cases.

Ranchers have been encouraged to monitor herds and local wildlife closely.