A second case of the New World Screwworm, the flesh-eating parasite that infects calves and poses threats to the U.S. cattle industry, was detected in Texas on Friday, according to the U.S. Department of Agriculture.
The first domestic case of the larvae was discovered in Zavala County roughly 100 miles southwest of San Antonio on Wednesday, after months of a rising number of cases in northern Mexico worried cattle farmers and Texas agriculture officials. A second case – roughly 5.6 miles from the first one – was confirmed Friday in a 1-month-old calf, the USDA said in a news release.
The parasitic flies lay eggs in open wounds and feed on living flesh, causing damage – and often, death – to livestock. In rare cases, the maggots can infect humans.
They pose a threat to the state’s $17 billion cattle industry, which produces more beef than any state in the U.S. The flies can also infest any warm-blooded animals, including wildlife and pets.
A federal response team collected samples to look for any additional screwworm cases in Zavala County near where the second case was detected, and they all came up negative, the USDA said.
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Once widespread across the southern United States, the flies were eradicated domestically in the 1960s. The USDA said the cases detected this week are the first in Texas since 1966.
As of Wednesday, officials had reported more than 171,700 animal cases and more than 2,070 human cases in Mexico and Central America.
On Friday, before the second case was announced, Gov. Greg Abbott pledged to deploy state resources to combat the infestation.
“We’re in the season for spread, and it’s going to be an extraordinarily challenging summer to get through this,” Abbott said during a briefing with state officials in Austin.
Federal and state officials are releasing hundreds of thousands of sterile flies to try and stop the spread – a strategy meant to have sterile males mate with females so their eggs never hatch into the flesh-eating maggots that infect livestock. Female flies only mate once in their weekslong adult lives.
In February, the U.S. Department of Agriculture opened a facility in Edinburg to release the sterile flies. The USDA plans to open a factory nearby to breed the flies by the end of next year.
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Michael Schmoyer, who is leading the U.S. Department of Agriculture’s screwworm directorate, said the government was releasing about 500 million sterile flies a week to drive the pests out of the country during the last infestations decades ago. He said the USDA is only releasing about 100 million flies right now.
“We are looking at building up to that number, but we’re also using science and technology and innovation to do whatever we can to make the best use of the flies that we have, and hopefully decrease that number,” he said.
Abbott declared the larvae a disaster last year, and he expanded the declaration Friday to use “all available resources of state government to respond.”
State officials urged people to check their pets regularly, especially if they have any open wounds and contact their veterinarian immediately if they see what they suspect to be larvae. They also urged against moving infested animals to prevent the flies from spreading.
Staff writer Benjamin Wermund contributed to this report.
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This article originally published at Second screwworm case confirmed in Texas about 100 miles from San Antonio.