Three things to know about the New World Screwworm fly

The New World screwworm is a dangerous parasite that can cause severe, often deadly damage to animals, and it's getting closer to the U.S. border.

What is the new world screwworm?

According to the U.S. Department of Agriculture, the New World screwworm is a “devastating pest.”

The USDA states: “When NWS fly larvae (maggots) burrow into the flesh of a living animal, they cause serious, often deadly damage to the animal. NWS can infest livestock, pets, wildlife, occasionally birds, and in rare cases, people.”

Right now, the NWS is endemic to Cuba, Haiti, the Dominican Republic, and countries in South America. The parasite was rampant in the United States in the 1960s and 1970s, but has not been a problem since then.

The new world screwworm has re-emerged in Mexico and has been found in multiple farms in Oaxaca, which is about 70 miles away from the border. 

What is the potential economic impact if screwworm does make its way into the US?

The last time the screwworm was in the United States was in the 1960s-70s. 

“The loss of production is millions and millions of dollars,” said Sen. Casey Murdock, R-Felt.

The parasites had an economic impact of more than $10 million at that time.

With inflation, lawmakers expect that to be about a $1.8 billion impact right now. “It was $81 per head to treat an animal. If you figure in inflation today, it's $452 an animal.” 

What measures are being taken to prevent screwworm in Oklahoma?

“I would add this to the list of something that is certainly keeping us awake at night,” said Blaine Arthur, Oklahoma Secretary of Agriculture. 

The U.S. Department of Agriculture (USDA) has temporarily halted the import of live cattle, horses and bison from Mexico.

“I think the fact that they have said we are closing the border is a perfect example of how important it is to protect the herd health of our cattle industry here in the United States and they don't mind making tough decisions to do that,” said Arthur. 

Secretary Arthur and Dr. Rod Hall, the State Veterinarian, met with state lawmakers to talk about potential plans if the screwworm makes it into the U.S.

“The issue is already in Mexico. I understand it could be heading our way. It's in our best interest to take this seriously,” said Rep. Kenton Patzkowsky, R-Balko. “Once it gets closer here, if it gets into Texas, then we need to start doing surveillance.” 

Agricultural leaders say that would include working with researchers, vets and ranchers across the state to try and keep things under control.