The number of animals infested with New World screwworm (NWS), a flesh-eating parasite, has risen by 53% in the four weeks to mid-August, Mexican government data reveals.
While infestations by the fly larvae primarily affect cattle, Mexican officials also registered cases in dogs, horses, sheep – and humans.
According to local media, dozens of people have been treated for the infestation in hospitals in the southern Mexican states of Campeche and Chiapas.
The rise in affected animals in Mexico comes just days after US health authorities said that they had confirmed the first human case in a patient who had returned to the US from El Salvador.
NWS was declared eradicated in the US in 1966 after sterile male flies were released to disrupt the insects' reproductive cycle, and Mexico followed suit in 1991.
