One day after the flesh-eating New World screwworm parasite was detected in a Texas calf, the U.S. government confirmed on Thursday (June 4) that there were no further detections of the screwworm in the area around the La Pryor, Texas, case and Texas officials assured the public that they are equipped to deal with the incident.
“For, for the situation we currently have, we have sufficient flies to suppress it," said Phillip Kaufman, who heads Texas A & M's entymology department and works with Texas' New World Screwworm Response Team. "But if it showed up on a wide swath of Texas, all of the flies that we're currently releasing in northern Mexico would likely be redeployed to Texas, and then that stops us from releasing flies in northern Mexico, and now the population moves closer and closer to the border.”
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 case was a blow to U.S. cattle ranchers who have been bracing for a domestic screwworm outbreak as the pest advanced north through Mexico over the past year.
Rollins said the U.S. Department of Agriculture believed it could contain the case, the first in Texas since 1966. Wider infestations could further shrink the U.S. cattle herd, which is the smallest in 75 years.
Kaufman said the most effective way to control New World screwworms is to release sterilized male flies that mate with females, producing unfertilized eggs and halting reproduction.
“We can use sterile insect technique and release, mass release sterilized males that will mate with the female that will only mate one time and she then, she then will lay unfertilized eggs and we can get rid of this fly very quickly. That process takes several weeks to be completed," he said.
Rollins explained that the challenge is the sheer number of flies that would be needed should there be a widespread outbreak.
"The challenge is we need about 400 to 500 million flies a week to push it back and we had gotten to the point - because no one thought it was going to be a threat again - that we're only producing 100 million a week and that's down in Panama. So that's what we're working to solve for right now," she said. "We do not believe this will be an infestation. We’ll be able to isolate each case. We've had a year to prepare because we pushed it off a bit and we have the teams on the ground ready to go."
There is currently one facility in Panama that produces the flies. The U.S. said it is building a plant in Metapa, Mexico, aimed at stopping the insect before it reaches the United States, and plans to eventually build another facility in Texas.
“What USDA has shared with us in the past is they have invested in a plant in Metapa, Mexico, that they hope to have online, I believe, by the end of June, and it will take them some time to ramp up their production and that they will add 100 million flies (per week) to what we currently have, which will essentially double our current production. That is fantastic. Those are much needed flies," Kaufman said. "They're also building a facility down in Edinburg, Texas, on Moore Air Base that in a year, in about a year and a half, that will add another 100 million flies, which of course is fantastic. A year later, they expect to add 200 million more to get to 500 million total flies.”
Kaufman said USDA researchers have developed a technology called NovoFly that produces only male flies, potentially doubling effective output. The method has not yet been approved but could significantly boost response capacity.
“They've developed a fly strain where during when they raise them as larvae, there is a food additive that if they take that out, all the female flies die. So they can essentially put twice as many eggs into a container, knowing that half of them will die and there's enough food for the rest of them that are in there and all of them that survivor are males," Kaufman explained. "It's very exciting, and we're hoping that that process moves along and and they are doing due diligence to make sure it's done correctly.”
The detection of the New World screwworm threatens Texas' livestock industry, which could face up to $1.8 billion in estimated economic losses if screwworm spreads, experts said.
Posted by: AAngeles/NET25 News
