USDA Shifts Sterile Fly Dispersal Efforts to Defend U.S. Border
APHIS Press Release
January 30, 2026
Washington, D.C.- The United States Department of Agriculture's (USDA) Animal and Plant Health Inspection Service (APHIS) is announcing a shift in its 100 million per week sterile fly dispersal efforts to stop the northern spread of New World screwworm (NWS). USDA will reallocate aircraft and sterile insects to reinforce coverage along the U.S.-Mexico border. The new dispersal area, or polygon, will include operations about 50 miles into Texas, along the U.S. border with the state of Tamaulipas, Mexico. Mass production and targeted dispersal of sterile insects are critical components of an effective strategy to fight NWS. Other tools including import protocols and surveillance continue to support these robust efforts to keep NWS out of the United States.
"At Secretary Rollins' direction, our highest priority is protecting the United States from screwworm," said Dudley Hoskins, Under Secretary of Marketing and Regulatory Programs for USDA. "The northernmost active case of NWS in Mexico is still about 200 miles away from the border, but we've seen cases continue to spread in Tamaulipas and further south in Mexico, so we are proactively shifting our polygon as we make every effort to prevent NWS from reaching our border."
Sterile Fly Dispersal
Sterile insect technique, when paired with surveillance, movement restrictions, and education and outreach, is an effective tool for controlling and eradicating New World screwworm. Female New World screwworm flies only mate once in their lives, so if they mate with a sterile male, they lay unfertilized eggs that don't hatch. Releasing sterile flies just outside of affected areas helps ensure flies traveling to new areas will only encounter sterile mates and will not be able to reproduce. In this instance, USDA will release sterile flies north of the current active NWS cases in Mexico in a proactive effort to create a sterile reproduction buffer zone if the fly moves north from Mexico.
Because it is important to continue ongoing surveillance efforts while releasing sterile insects, it is possible that sterile NWS flies could be caught and/or reported within Texas. To ensure officials can tell the difference between sterile and wild NWS flies, USDA will dye the sterile pupae, and the dye will transfer to the sterile flies when they hatch. The fluorescent dye will glow under UV light and may also be visible to the naked eye. If a sterile fly is captured in a trap, this dye will allow animal health officials to quickly rule the fly out as a threat.
USDA will continue to deploy its intensive NWS response efforts including implementing import protocols, ongoing surveillance and trapping efforts along the border, investing in NWS innovation, and supporting robust response activities in Mexico and Central America.
U.S. Begins Dropping Sterile Flies in Texas as New World Screwworm Inches Closer to Home [equine detection]
Texas issues a statewide disaster declaration and USDA makes strategic reallocation of sterile flies to safeguard the U.S. livestock industry and public health.
By Angie Stump Denton
Drovers.com
January 30, 2026
New World screwworm (NWS) is inching closer to the U.S. Last week Mexico reported eight new cases in the U.S. neighboring-state of Tamaulipas. A key to slowing down the threat is being proactive.
U.S. Department of Agriculture's (USDA) import requirements and protocols are one line of defense for NWS and other foreign animal diseases that threaten U.S. livestock. According to USDA, earlier this week, a horse from Argentina was presented for routine importation at an equine import quarantine facility in Florida.
"Upon examination, APHIS identified an open wound with larvae on the animal and promptly collected and shipped samples to the National Veterinary Services Laboratories (NVSL) in Iowa. The horse was immediately treated with medication to kill any larvae in accordance with standard, long-standing import protocols." the release explains. "This morning, NVSL confirmed that the larvae were NWS larvae. Accordingly, the animal will remain in quarantine until it has been reexamined and determined to be free of NWS."
This is an example of import protocols working as designed. While this situation does not appear to be associated with the NWS outbreak in Mexico, the release says it underscores the need for vigilance in all of USDA's coordinated efforts to fight NWS.
Full text: https://www.drovers.com/news/industry/usda-texas-act-stop-spread-new-world-screwworm
H5N1 bird flu outbreak enters fourth year in U.S. [edited]
By Patrick Cooley
Farm and Dairy
January 29, 2026
SALEM, Ohio - As the spread of highly pathogenic avian influenza enters its fourth year, experts who track the disease are continuing to express concern over the virus's capacity to jump to animals that aren't birds.
"The one thing that has been different is the potential to see it more in other animal species, especially in dairy herds," said Joe Moritz, a professor of dairy science at West Virginia University.
Since the bird flu outbreak began in the United States in February 2022, the virus has killed 186.2 million birds in all 50 states and Puerto Rico, according to USDA data.
As of now, poultry can't be immunized from the virus, and some of the vaccines in development are impractical, Moritz said. One such vaccine would be administered through the nose, he said.
"An average [poultry] farm can have thousands of birds," and giving each of them a nasal vaccine would be a struggle, Moritz said.
But researchers are working on alternatives. West Virginia University was recently awarded a $2 million grant to develop an edible vaccine, Moritz said.
Full text: https://www.farmanddairy.com/news/h5n1-bird-flu-outbreak-enters-fourth-year-in-u-s/903004.html
Colorado Lt. Gov. Primavera issues disaster declaration for avian flu in Weld County
By Jennifer McRae
CBS Colorado
January 30, 2026
Colorado Lt. Gov. Primavera, as acting governor while Gov. Jared Polis is in Washington DC to attend the Colorado River negotiation meeting, issued a verbal disaster declaration for avian flu in Weld County.
According to the Colorado Governor's Office, the outbreak is of highly pathogenic avian influenza. The disaster declaration enables state agencies to properly coordinate for mitigation of disease spread, response, consequence management and recovery efforts.
The declaration was made in coordination with Gov. Polis, according to the governor's office.
Avian Flu in five cows in the Netherlands; Avian flu in Lancaster, CO Pa commercial egg-laying facility
CIDRAP News
January 30, 2026
Today, Avian Flu Diary notes the discovery of antibodies against H5N1 avian flu in five cows in the Netherlands, although officials have yet to confirm the finding. The infectious disease news blog cited the source as the Netherlands public broadcasting network. The cows were located in Northeast Friesland in the Netherlands' far north. The news comes a week after the Dutch government announced its first case in a cow in the same province. The case was detected after one of two sick kittens on a dairy farm tested positive for avian flu. After screening cows on the farm, one was found to have antibodies against avian flu. The cow had mastitis and respiratory symptoms in December, two years after the detection of avian flu in Texas cattle in a spillover event. The country has recently seen a number of avian flu outbreaks in birds, including in a pet store and a petting zoo.
Avian flu has hit a Lancaster County, Pennsylvania, commercial egg-laying facility with more than 1.5 million birds, per the US Department of Agriculture's Animal and Plant Health Inspection Service. In the past month, 17 commercial flocks and 42 backyard flocks have been affected by the virus, for a total of 2.8 million affected birds.
3. Progress on Ohio's Veterinary Diagnostic Laboratory continues
Ohio Country Journal
January 27, 2026
Ohio is making a major investment in animal health, biosecurity, and food safety with the construction of a new Ohio Veterinary Diagnostic Laboratory on the Ohio Department of Agriculture's campus in Reynoldsburg. In this interview, Brian Baldridge, Director of the Ohio Department of Agriculture, discusses the progress of the 70,000 square foot, state-of-the-art facility and how the project will better serve Ohio's farmers. The new laboratory will replace the existing facility that dates back to the 1960s and has outgrown current testing demands. Once complete, the building will strengthen Ohio's ability to detect and respond to animal disease while keeping critical diagnostic testing within the state.
Source: https://ocj.com/2026/01/progress-on-ohios-veterinary-diagnostic-laboratory-continues/
4. Know your dewormer
By Sandy Stuttgen
Wisconsin Agriculturalist
Farm Progress
January 29, 2026
Internal parasites, also known as helminths or "worms" such as Cooperia, Ostertagia and liver flukes, threaten the productivity of grazing beef and dairy cattle. Deworming is widely practiced, and many studies show it can be economical. However, nutrition and good management can mask the production losses caused by internal parasites, and resistance to anthelmintics continues to grow.
For these reasons, farm managers cannot judge the value of their deworming program unless they use strategic fecal egg counts and fecal egg count reduction tests. Only then can they determine whether the product they used is still effective and therefore economical.
Currently in the U.S., numerous name-brand and generic products fall into just four anthelmintic drug classes: avermectins (macrocyclic lactones), benzimidazoles, imidazothiazoles and sulfonamide derivatives.
Each class has a distinct molecular structure that harms parasites in a different way. Awareness of these differences helps producers prevent parasites from developing resistance to the drug class, not just to a specific product.
Full text: https://www.farmprogress.com/cattle-news/know-your-dewormer
5. Sales of antibiotics for farm animals spiked in 2024
KMALand
January 31, 2026
A little over a decade ago, in 2015, farmers in the U.S. purchased more than 10,000 tons of "medically important" antibiotics-the same drugs used for people in hospitals and doctors' offices-for their chickens, pigs, and cattle.
They used these drugs to prevent diseases and treat infections, and to make their animals to grow faster.
But growing concern over antibiotic resistance and agriculture's role in driving the threat led to a groundswell of public opposition to overuse of the drugs, which brought about a determined decrease in use by food companies and an important change in federal regulations.
By 2017, the volume of medically important antibiotics sold for farm animals was nearly cut in half, where it remained fairly steady year after year. In December 2025, however, when the FDA released its annual report, things had changed: In 2024, the volume climbed 16 percent.