By Cassandra Garrison
TAPACHULA, Mexico (Reuters) -On a scorching afternoon in the rural heartland outside Mexico's southern city of Tapachula near the Guatemala border, rancher Julio Herrera calls his herd back from an afternoon of grazing.
"Gate! Gate!" he hollers as the cows turn the corner from the pasture and trot instinctively to their corral.
He runs his hands under their hooves, feeling for wounds through which the deadly screwworm parasite could burrow inside their bodies. Efforts to protect
his herd can only go so far, he says, until Mexico's government steps up to tackle what he considers the core issue: illegal livestock moving unchecked across the border from Central America.
Maggots from screwworm flies burrow into the flesh of living animals, causing serious damage. While it can often be fatal, infected animals can be treated by removing larvae and applying medications, if it is detected early enough.
The infestation, which began in November, has now claimed its first human casualty: an 86-year-old woman with advanced cancer and complications from a screwworm infection who died in the state of Campeche in late July. While infections are rarer (and treatable) in humans, Mexico confirmed more than 30 cases in people in the last week of July.
"From Guatemala there is indiscriminate passage of stolen cattle, sick cattle. There is no health control," Herrera told Reuters. "We, the producers, are the ones who suffer."
Estimates cited by Mexican authorities in 2022 and others by sector experts indicate the number of illegal cattle crossing into Mexico is at least 800,000 per year.
Organized crime groups have long been linked to the theft and trafficking of livestock, which enables them to tap a lucrative market and extort money along the way. The animals may come from Guatemala, Honduras, Nicaragua or other Central American countries. They enter Mexico with black market ear tags and falsified documents.
CLOSED BORDER
Local veterinarians in Chiapas, slaughterhouse professionals and producers said the illegal crossings were a major factor in the outbreak. These animals bypass government checkpoints, sanitary inspections and taxes, and are then sold to meat companies or larger cattle producers.
While local government officials in Chiapas acknowledged the illegal trade, they said it was being handled by the federal government - and was not the main factor in the spread of screwworm. Instead, they blamed the unchecked movement of the screwworm fly and a failure to report cases and seek treatment.
Mexico's Ministry of Agriculture did not respond to questions about measures to stop illegal livestock at the southern border, but pointed to past statements on efforts to reduce counterfeit and unauthorized ear tags.
The U.S. has kept its border mostly closed to Mexican cattle since May because of the outbreak, dealing a heavy blow to an industry that exports approximately a billion dollars’ worth of cattle to the U.S. annually, and contributing to high beef prices in the U.S. The outbreak is costing the Mexican meat industry an estimated $25 million to $30 million a month, according to the Mexican Association of Meat Producers (AMEG).
Three ranchers told Reuters they are increasingly angry over the government's lack of control at the southern border. In July, Mexico's National Confederation of Livestock Organizations called on the government to redouble efforts to control illegal crossings.
"It's a business," said Jorge Ortiz of the Tapachula municipal slaughterhouse and a local pig farmer, about illegal livestock. "It needs a lot of attention to be able to control this problem... and where that should come from is the federal government."
The outbreak is bringing fresh trade tensions to the U.S.-Mexico trade relationship as Mexico has three months to negotiate a trade deal with the U.S. or face increased tariffs.
Mexico's federal government is working on a $51 million plant in Chiapas to breed sterile screwworm flies, with the help of $21 million from the U.S., though it is not expected to begin operating until 2026.
DISPELLING MYTHS
Officials have said that infected animals will not be slaughtered.
A few screwworm-detecting dogs have been deployed to a Chiapas livestock border crossing and training sessions and free care, such as de-worming products, are offered to producers who report infected animals.
Chiapas state Agriculture Secretary Marco Barba said local efforts are focused on awareness and prevention. Signs are posted around towns with slogans such as "Without wounds, there's no worms."
Authorities are also trying to dispel myths about contaminated meat, Barba said, adding that consumption has dropped in the state. Officials have said that screwworm infections are not transmitted through the consumption of meat.
Livestock producers hesitate to report screwworm cases because they fear officials could shut down their business or slaughter their animals, said Carlos Mahr, president of the Livestock Union of Chiapas.
At Mahr's ranch outside Tuxtla Gutierrez, a worker lassos a young cow. The animal bucks as it is guided over to Mahr, who is waiting with an aerosol can of disinfectant used to clean the wound left from removing the animal's horns.
Infected animals can be easily treated, Mahr said. "There should be no fear or worry," he said. "Reporting is important to have a generalized map of where the worm is found."
It is vital for the country's cattle producers that the border with the U.S. reopens, Barba said, and his government has been working to show USDA officials that there's progress.
U.S. Agriculture Secretary Brooke Rollins has said the U.S. is working more closely with Mexico than ever before and that the USDA team was "staffing up in the hundreds" to get into Mexico to verify the data the country was providing.
The resources, though, haven't trickled down to everyone.
Alfonso Lopez, a livestock veterinarian in Tapachula, said he sees cases every day, on several ranches.
"Right now, it's a very serious situation," Lopez said from his office, where he had a fresh sample of screwworms collected from a newborn calf earlier that day.
"What the federal government is doing, which isn't enough, is sending personnel to address the cases, but Chiapas isn't just highways... it has mountains and valleys, and so the fly isn't going to travel only on the roads. It's insufficient," Lopez said.
While controlling screwworm in livestock is the main priority, Herrera, the rancher in Tapachula, noted that the pest can infect any warm-blooded animal.
"What happens with the coyotes, the stray dogs... the deer, the jaguar?" Herrera said.
(Reporting by Cassandra Garrison; Editing by Christian Plumb and Claudia Parsons)
