A suspected case of the flesh-eating New World screwworm has sparked alarm in Texas, raising fears the deadly parasite may have crossed into the United States for the first time in decades.
The US Department of Agriculture (USDA) confirmed on Wednesday that samples from a possible infection have been sent for urgent testing.
Officials said: “A case of NWS may have been detected in South Texas. The sample is now at USDA’s National Veterinary Services Laboratories (NVSL) in Ames, lowa for confirmatory testing.
“We will provide updates the moment results are available. We have already activated personnel on the ground and are working with local partners. What you can expect from us is transparency, candor, and most important — action.”
The discovery comes after weeks of growing concern among farmers and ranchers as the parasitic fly continues its relentless march north through Central America and Mexico.
The screwworm poses a major threat to livestock. Female flies lay hundreds of eggs in open wounds on animals, with the hatched larvae then feeding on living flesh. The infestation can cause deep, infected wounds and can prove fatal if left untreated.
Humans can also be affected, although cattle and other livestock are particularly vulnerable.
The parasite was wiped out in the United States during a massive eradication campaign in the 1960s. Since then, keeping screwworms out of the country has saved the US livestock industry an estimated $900 million (£665 million) every year.
But recent cases discovered just miles from the Texas border have fuelled fears that the pest is making a comeback.
Last month, officials confirmed a screwworm infection in a goat just 25 miles from the border in Mexico. Another case was found in a calf only 39 miles away.
US Agriculture Secretary Brooke Rollins warned the threat is “very, very serious” for American livestock producers.
The USDA has already deployed personnel on the ground and is working with local partners while tests are carried out.
To stop the spread, authorities are releasing around 100 million sterile flies every week across Mexico and along the border. The technique prevents breeding and was instrumental in eliminating the pest from North America decades ago.
The US is also ramping up surveillance efforts and building a new sterile-fly production facility in South Texas as officials race to prevent the parasite from establishing itself north of the border.