As USDA was confirming detection of New World screwworm in a three-week-old calf in La Pryor, Texas, U.S. pork producers were gathering in Des Moines, Iowa, for the World Pork Expo. Although La Pryor is over 1,000 miles away, the somber reality of this devastating pest crossing over into the U.S. was felt around the Iowa State Fairgrounds.
“It’s important for people to understand that this particular pest can affect any warm-blooded mammal,” says Anna Forseth, director of animal health for the National Pork Producers Council. “A lot of attention has been given to the cattle industry, and rightfully so. The highest risk state geographically is Texas, and they have a huge cattle industry raised on pasture or that have exposure to the outdoors.”
Don’t Dismiss the NWS Threat
But, she’s quick to point out that other livestock, domestic pets, wildlife and people are all at risk for exposure and potential infestation with this particular pest.
“The pork industry has been engaged in the conversation knowing that there is a potential risk for us,” she confirms.
Todd Marotz, vice president of the National Pork Producers Council, says the timing of the NWS confirmation comes off the heels of pseudorabies rearing its head for the first time in a commercial swine herd since 2004. Both serve as reminders about the threat that feral swine play in the spread of disease and pests.
“I think the important thing for pork producers to feel good about is in the journey that the New World screwworm took through Mexico, there wasn’t a single report of a commercial swine facility that was infected along the way,” Marotz says. “However, we need to monitor and do our due diligence as far as what’s right for the industry and making sure that we do our part.”
Texas is home to an estimated 3 million feral pigs – the largest population of feral swine in the U.S.
“Texas wildlife officials, as well as USDA wildlife services, have been engaged to consider how to handle this in the feral pig population,” Forseth says. “They are discussing the best management opportunities and practices, managing infestation and active surveillance of all wildlife species.”
Do We Have Enough Sterile Flies?
The sterile fly technique is the only true opportunity to combat this particular pest, explains Forseth.
“Any opportunity to push it back down south will come with the sterile fly technique,” she says. “This management practice was deployed the last time the United States dealt with NWS. The female will only mate once in its lifetime. If we can put an overabundance of sterile flies into the population and increase the chances that a female screwworm fly will mate with a sterile fly, then over time that helps control the population of NWS flies.”
The USDA has been focusing time and resources to increase the number of sterile flies produced to fight this battle.
“The federal government’s interest in increasing our production numbers may suggest that currently we don’t have enough sterile flies at this time,” Forseth says. “The more sterile flies we can put into the environment, the better our chances are at decreasing their survivability and their potential to continue moving further into the U.S.”
Prevention is Possible
Patrick Webb, assistant chief veterinarian at the National Pork Board, agrees that producers play a key role.
“Vigilance is the most important thing that we can do right now to limit impact here,” Webb shared with Chip Flory on AgriTalk at the World Pork Expo. “That means monitoring your herd, and I don’t care if you’re in Texas or in Iowa, you’ve got to monitor that herd and know what to look for. Go to screwworm.gov – they have a lot of great resources there to help producers understand what to look for, but more importantly, how to report it, and what to do.”
Webb says early detection is critical. Pay close attention to wounds, scrapes, even needle pricks, bite marks and tick bites.
“Even if you have a slight suspicion in a situation like this, make sure that you’re working with your herd vet and you’re reporting to the state animal health official,” Webb says. “It’s not going to hurt if it’s not NWS. We need to be on top of this thing as fast as possible from a regular regulatory disease control side of things.”
He expects that some states will require new information on health papers to move pigs across state lines.
“If you’re in an infested zone, you may have to do certain things,” Webb says. “Work with your herd veterinarian to make sure you understand the new rules. Remember, one of the highest risk pathways for movement of NWS is the movement of an infested animal.”
Marotz encourages producers not to overreact, but to take this announcement seriously.
“We want to make sure that we’re doing everything we possibly can to protect our industry and to protect trade,” Marotz says. “With 25% to 30% of U.S. pork production going overseas, our trading partners are very important to us. That’s why we need to be open and upfront with them and handle this appropriately.”
