US suspends import of live cattle from Mexico over fear of flesh-eating maggots

US temporarily suspends import of live cattle from Mexico due to fear of maggots eating flesh - Photo 1.

The New World screwworm is endemic to parts of Latin America and the Caribbean. Its spread north into Mexico has U.S. officials concerned - Photo: USDA

According to Reuters, on May 11, the US government ordered a temporary halt to all live livestock imports from Mexico, including cows, horses and bison, due to concerns about the spread of the New World screwworm - a dangerous parasite capable of eating its host.

The decision was announced by US Secretary of Agriculture Brooke Rollins after the parasite was discovered in southern Mexico last year.

She affirmed that this is a national security issue, directly related to food safety and animal health, and not political or punitive to Mexico.

New World screwworms are fly larvae that can invade open wounds or mucous membranes of animals, rarely humans. When parasitic, they use small hooks in their mouths to feed on the flesh and blood of their hosts.

If left untreated, an infection caused by this parasite can kill an adult cow in just one to two weeks.

Once eradicated from the US and Mexico in the 1960s and 1970s by releasing sterilized male flies to prevent reproduction, screwworms have reappeared in many parts of Central America and remote farms in Mexico, about 1,130km from the US border, raising high alarm.

The US suspended live animal imports from Mexico in November 2024, and only resumed them in February this year after an agreement was reached to control the disease between the two countries. However, given the current situation, the ban will be re-imposed and maintained on a monthly basis until the situation is under control.

In 1976, a screwworm outbreak in Texas (USA) affected more than 1.4 million cows, hundreds of thousands of sheep and goats, causing great damage to the agricultural industry. According to the US Department of Agriculture (USDA), if the outbreak recurred at the present time, the Texas economy could lose up to 1.8 billion USD.