First US screwworm case in 60 years: Should America be worried?

Key points

• The US Department of Agriculture says New World screwworm has been detected in a Texas calf.
• The New World screwworm, a flesh‑eating parasite which infects cattle and other warm‑blooded animals, has been found in a calf in Texas, the US Department of Agriculture announced on Wednesday.
• The screwworm is believed to have travelled from Central America to Mexico before being found in the calf in Texas, evading biological barriers that have kept the pest contained for decades, experts said.
• Screwworm was previously declared eradicated in the US in 1966. Between mid-July and mid-August 2025, Mexico reported a 53 percent rise in the number of cases in animals.
• Humans can also be infected.