US scrambles to contain flesh-eating screwworm outbreak

After the first confirmation of the flesh-eating parasite screwworm on a US farm in decades, federal and state officials have fanned out in South Texas, where a calf was found infested this week. US agriculture secretary Brooke Rollins said on Thursday no other infestations of cattle or other animals have been detected around the confirmed case. The case in La Pryor, Texas, is a blow to US cattle ranchers who have been bracing for a domestic outbreak of New World screwworm as the fly advanced north through Mexico over the past year.

The US department of agriculture broke ground in April on a facility to produce sterile flies, which experts describe as the best tool for combating the pest, but it will not come online until late 2027. The federal agency and Texas officials quickly halted the movement of animals in a 20km area around the case and took other steps to prevent the parasite from spreading. Every major road out of La Pryor is marked with a blinking orange road sign urging all vehicles carrying livestock to pull over to a checkpoint staffed with sheriffs and state personnel who inspect the animals for signs of screwworm.

“If we all work together and follow these treatment and movement restriction guidelines, there is no reason to believe this incursion will result in any sort of establishment of the pest on our side of the border,” Rollins told reporters on a call. She earlier told US lawmakers the agriculture department believed it could contain the case, the first in Texas since 1966, and has also said screwworm is not a food safety threat. Traders fear wider infestations could further shrink the US cattle herd, which is the smallest in 75 years, and dampen US consumer demand for beef.

[paywall]

Screwworms are parasitic flies whose females lay eggs in open wounds and mucous membranes on any warm-blooded animal. Once the eggs hatch, hundreds of screwworm larvae use their sharp mouths to burrow through living flesh, eventually killing their host if left untreated. “The New World screwworm sounds like something from a horror movie, but it’s real,” said Nate Sheets, a Republican nominee for Texas agriculture commissioner.

“It is an agricultural emergency.” Feeder cattle futures initially dropped on the Chicago Mercantile Exchange on Thursday as traders worried the infestation could reduce consumers’ appetite for beef. Futures quickly rallied more than 3%. The detection threatens Texas’ livestock industry, which could face up to $1.8bn (R29.3bn) in estimated economic losses if screwworm spreads widely, experts said.

“We’re going to need to see how fast it spreads and how the consumer reacts,” said Matt Wiegand, commodity broker for FuturesOne. “Until we see a big demand impact from the consumer side, (cattle) numbers are still tight.”

[/paywall]