06/10/2026
The United States Department of Agriculture (USDA) has confirmed that the New World Screwworm – an invasive, destructive parasite – has been detected in Texas and New Mexico, marking the pest’s first incursion into the United States since it was successfully eradicated in the 1960s.
Current Status for California
There are currently NO confirmed detections of New World Screwworm in California. The California Department of Food and Agriculture (CDFA) is actively monitoring the situation and working closely with local, state, and federal health officials. Because of the screwworm’s spread northward through Central America and Mexico into Texas and New Mexico, California is taking proactive steps to protect our agricultural economy, wildlife, and workers.
Best Practices
* Check your animals daily: The absolute best defense is keeping an eye on animals. Routinely inspect livestock, horses, and pets for any signs of wounds or unusual fly activity. It’s important people traveling with their pets to and from Mexico and other infested regions carefully check them for wounds or signs of infestation.
* Treat wounds immediately: Keep any open wounds clean, treated, and covered to prevent flies from laying eggs.
* Monitor travel requirements: If you are moving livestock, please check the CDFA website frequently for any new entry or movement restrictions regarding animals coming from infested states.
* Know the human risk: Human cases are incredibly rare, isolated, and cannot spread from person to person like a virus.
* What to do if you suspect Screwworm: Do not wait. If you see signs of unusual larvae in an animal’s wound, immediately contact your local veterinarian or reach out directly to your CDFA District Office.
Stay Updated
For the latest official data and status maps, please monitor these tracking pages:
* California: CDFA NWS Updates Page
* Federal Tracking: USDA APHIS Current Status
* Texas: Texas Animal Health Commission Updates
* New Mexico: New World Screwworm Awareness