The US has closed its ports of entry to Mexican cattle for fear of the parasitic, flesh-eating worm spreading north.

Mexican President Claudia Sheinbaum has denounced a decision by the United States to once again suspend imports of her country’s cattle over a flesh-eating parasite called the screwworm.

On Thursday, Sheinbaum used her morning news conference to call fears of the worm overblown. She pointed out that a single case in the eastern state of Veracruz had prompted the import pause.

“From our point of view, it is a totally exaggerated decision to close the border again,” Sheinbaum said.

At the centre of the cross-border debate is the New World screwworm, a species endemic to the Caribbean and parts of South America. It had previously been eradicated from the northernmost part of its range, in Central and North America.