How New World screwworm could infiltrate Minnesota

New World screwworm, a gruesome parasite, was recently discovered in cattle and pets across Southern states. Now, Minnesota officials worry it could make its way here.

The screwworm is a fly that lays its larvae on open animal wounds or orifices. From there, the screw-shaped worms drill into the animal, “devouring flesh and causing severe, painful wounds and infections,” according to the Center for Infectious Disease Research & Policy
Research and Innovation Office at the University of Minnesota.

In rare cases, the parasite can even infest people.

The U.S. Department of Agriculture confirmed the parasite was found in a 3-week-old calf in Texas on June 3. From there, more cases have popped up in the state. A pet in New Mexico was also confirmed to have been infested.

The screwworm has so far been contained to the South. Still, Brian Hoefs, the Minnesota state veterinarian, remains concerned it could make its way here through the movement of not only livestock but also pets.

“Anyone traveling with your dog to vacation areas that are endemic with this parasite needs to be aware that your dog can be infested as well, and you could be bringing it back on them,” said Hoefs.

Hoefs added that there are also import requirements in place for cattle that require a certificate of veterinary inspection.

Hoefs said the U.S. Department of Agriculture recently accepted a New World screwworm research proposal from his team. They’ll soon begin studying how to “develop and pilot practical screening, triage and referral protocols for animals arriving from endemic areas,” according to the proposal.

Minnesota Sen. Amy Klobuchar recently called for the federal government to hire more veterinarians to combat the screwworm. While the screwworm wouldn’t endanger the food supply, Hoefs said it could create additional price pressure on beef.

The risk of the screwworm establishing an ongoing population in Minnesota is almost nonexistent, Hoefs said. The screwworm would die off during the winter as it can’t survive cold temperatures.

But it could still wreak havoc in the short term.

“Where I’m concerned about it showing up is now,” said Hoefs. “During our warm weather, this is perfect weather for New World screwworm, even up here in Minnesota. We certainly have the right habitat and lots of critters that it could survive on.”