Mexico’s beef industry has been severely impacted by a New World screwworm (Cochliomyia hominivorax) outbreak that led the United States to close its border to Mexican cattle imports in May 2025 — a move that halted trade worth an estimated US$1 billion (R18 billion) annually.
Analysts say the export suspension has contributed to higher beef prices in the US, highlighting how deeply intertwined the two countries’ livestock industries are.
Smuggling Fuels Disease Spread
Farmers and industry leaders have blamed the outbreak on the smuggling of cattle from Central America — particularly Nicaragua, Honduras, and Guatemala — into southern Mexico.
According to InSight Crime, an organisation that investigates organised crime in the Americas, cattle smuggling serves multiple illegal purposes:
“It satisfies the global demand for beef while masking other criminal activities such as cocaine trafficking and money laundering,” the group reported. “In 2024, it also helped spread diseases and pests across the region, including the screwworm.”
Mexican authorities previously estimated that around 800,000 cattle are smuggled into the country each year. Reuters noted that organised crime groups have long been linked to livestock theft and trafficking, using black market ear tags and falsified documents to disguise the animals’ origins.
Veterinarians, slaughterhouse operators, and producers in Chiapas, a southern Mexican state bordering Guatemala, confirmed to Reuters that smuggled cattle were a major factor in the outbreak.
“These animals bypass government checkpoints, sanitary inspections, and taxes, then enter legitimate supply chains,” one report said.
However, some local government officials in Chiapas dispute this, arguing that the outbreak was driven more by the unchecked movement of the screwworm fly itself and a failure to report and treat infestations promptly.
Government Response
In response, Mexico’s federal government has announced plans to construct a US$51 million (R904 million) sterile screwworm fly breeding facility in Chiapas, with US$21 million (R372 million) in support from the US. The plant aims to control the pest population but is not expected to begin operations before 2026.
Producers Fear Reporting Infections
Carlos Mahr, President of the Chiapas Livestock Union, told Reuters that some producers are reluctant to report screwworm cases for fear their herds could be culled or businesses shut down.
Officials, however, have clarified that infected animals will not be slaughtered and can be treated successfully if detected early.
Screwworm infestations occur when maggots burrow into the flesh of living animals, causing severe wounds and potential fatalities. Early detection and treatment with larval removal and topical medication can prevent most losses.
As Mexico battles to contain the outbreak, experts warn that unless cross-border smuggling and weak enforcement are addressed, the country’s cattle industry could face lasting damage — with ripple effects across the North American beef market.
