Flesh-eating screwworm found in US for 1st time since 1966

A flesh-eating parasite known as screwworm has been detected in Texas, marking the first time since 1966 that the pest has been found in US livestock.

The US Agriculture Department said Wednesday that it had confirmed the detection of a New World screwworm (NWS) in a bovine in Zavala County, Texas. The pest had been declared eradicated in the US decades ago.

“NWS is a serious pest that affects livestock, pets, wildlife, and less commonly, people and birds. NWS larvae (maggots) burrow into the flesh of living animals, causing serious damage to livestock and economic losses,” the department said in a statement.

It noted that in the affected animal, a 3-week-old calf, larvae were identified in its umbilical area. To date, there have been no further detections, the department added.

The agency has deployed teams in Texas – the US’ second-largest state – to control and eliminate the parasite, establishing a 20-kilometer (12.4-mile) affected zone along with quarantines, movement restrictions, and enhanced monitoring efforts.

It is also accelerating the strategic release of sterile flies, which help suppress the local fertile fly population and reduce the parasite’s spread.

The department said it will “continue to work with state departments of agriculture, animal health officials, industry, and producers to mitigate economic impacts of restrictions as much as possible, including negotiating with our trading partners to regionalize any trade restrictions on live animals, limiting them to defined geographic areas.”

It also said that the risk of the parasite spreading to humans and pets is quite low and that the situation does not pose a threat to food safety.