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Tag: Screwworm

  • New World Screwworm Has Reached 16 U.S. Animals as Experts Say This Is Not an Isolated Incident

    New World Screwworm Has Reached 16 U.S. Animals as Experts Say This Is Not an Isolated Incident

    A flesh-eating parasite that the United States eradicated in 1966 has returned — and the 16 confirmed animal cases represent only the beginning of what veterinary experts and public health officials are working to contain.

    USDA’s Animal and Plant Health Inspection Service (APHIS) confirmed the first U.S. animal case on June 3, 2026, in a three-week-old calf in Zavala County, Texas, near the Mexico border. By the CDC’s most current accounting, 16 domestically acquired animal cases have been confirmed — spread across multiple Texas counties and Lea County, New Mexico, involving cattle, goats, and at least one dog.

    There have been no confirmed human infestations with New World Screwworm acquired in the United States. The Texas Animal Health Commission has quarantined a zone covering more than 20 Texas counties, and sterile fly releases are underway. But the public health challenge now is ensuring that ranchers, pet owners, and veterinarians understand what they are looking for — because what officials can count is likely only a fraction of what is actually out there.

    Why This Matters

    The New World Screwworm is not merely an economic pest. It is a uniquely dangerous parasitic fly because it targets living tissue — not dead or decaying material. The female fly lays eggs in any open wound, body opening, or skin abrasion on a warm-blooded animal. The larvae burrow into living flesh, producing compounds that attract more female flies, which lay more eggs, which produce more larvae. An infested, untreated animal can die within one week.

    The parasite affects cattle, sheep, goats, horses, deer, feral hogs, dogs, cats, and wildlife of all kinds. It can, in rare cases, infest humans — particularly through wounds or nasal passages. While human infestations in the United States are not expected under current conditions, the risk is not zero.

    The United States eradicated NWS domestically in 1966 using the sterile insect technique — a program that has been continuously maintained in Central America to prevent northward spread. The parasite’s reappearance now reflects the northward migration of screwworm populations from Mexico, where it was detected in Chiapas in November 2024 and has been spreading ever since.

    What We Know So Far

    From USDA APHIS, CDC, Texas Animal Health Commission, and the American Farm Bureau Federation:

    • First U.S. case: June 3, 2026 — a calf in Zavala County, Texas
    • Total confirmed U.S. animal cases: 16 domestically acquired (Texas and New Mexico)
    • Species affected: Cattle, goats, and at least one dog
    • Geographic spread: Multiple Texas counties, including Zavala, La Salle, Gillespie, and others; Lea County, New Mexico
    • Quarantine zone: More than 20 Texas counties covered by Texas Animal Health Commission quarantine orders; animals cannot be moved out of the zone without prior authorization
    • Sterile fly releases: More than 129 million sterile NWS flies released in the sterile fly release zone since February 2026
    • Human cases: No locally acquired human infestations in the U.S. confirmed
    • Food safety: USDA confirms the U.S. food supply is not at risk; NWS does not infest meat

    Where the Risk Is Highest

    The primary risk zone is South Texas — specifically the ranching and farming counties near the Mexico border. The Texas Animal Health Commission’s quarantine zone includes Bandera, Coke, Crockett, Edwards, Gillespie, Jim Hogg, Kerr, Kimble, La Salle, Medina, Pecos, Schleicher, Starr, Sutton, Terrell, Tom Green, Uvalde, Val Verde, Webb, Zapata, and Zavala Counties.

    A key vulnerability that concerns veterinary parasitologists is wildlife. White-tailed deer, exotic game species, and feral hogs are abundant throughout South Texas and can serve as NWS hosts. Unlike managed livestock, these populations cannot be routinely inspected. Any infested deer or hog can carry adult flies that then lay eggs on livestock or pets within the surrounding area.

    The confirmed dog case in Lea County, New Mexico — an area outside the primary South Texas detection zone — raises specific concerns about geographic spread through pet animals that may travel or that come into contact with infested wildlife.

    The American Farm Bureau Federation noted that the South Texas detection zone includes more than 160,000 sheep and goats, and many operations involve extensive rangeland where daily animal inspection is less common than on smaller farms.

    What Doctors and Experts Say

    “Report suspicions immediately,” said Bud Dinges, executive director of the Texas Animal Health Commission, in remarks following the first confirmed detection. “Quick notification leads to quick detection. A quick response will stop the pest from spreading.”

    USDA’s Rear Admiral Michael Schmoyer, APHIS Associate Administrator and Director of the NWS Directorate, said in June that the agency had deployed 8,000 fly traps at and near the U.S.-Mexico border and collected more than 58,000 fly samples and 19,000 wild animal samples — all of which had been negative for NWS at that time. That surveillance infrastructure is expanding as confirmed cases accumulate.

    Veterinary experts and livestock industry analysts have warned that confirmed cases represent only a subset of infestations that were both detected and reported. Animals in remote rangeland, wildlife, and feral hog populations are not systematically inspected, and infestations can progress rapidly before they are identified.

    What the Evidence Shows — and What It Does Not

    The epidemiological picture is confirmed: NWS is back in the United States. The current case count reflects only what has been detected and reported through the official surveillance system — which covers managed livestock that receive veterinary attention. Wildlife and large rangeland herds without daily inspection are almost certainly carrying more cases that have not been identified.

    Scaling sterile fly production to full eradication capacity — the method that successfully eliminated NWS from the United States in the 1960s — is expected to require 18 months to two years. That means U.S. ranchers and pet owners in the affected region face an extended containment period, not a quick resolution.

    MedicalDaily Evidence Check

    • Data source: USDA APHIS, CDC, Texas Animal Health Commission
    • Confirmed U.S. animal cases: 16 domestically acquired (Texas and New Mexico, as of most recent reporting)
    • Human cases: None confirmed in the U.S.
    • Available treatments: Multiple FDA Emergency Use Authorization (EUA)-approved products exist for cattle, horses, dogs, cats, and livestock; discuss with a veterinarian
    • Key limitation: Confirmed cases are an undercount; wildlife and large rangeland herds have limited inspection capacity
    • What readers should know: Livestock owners should inspect animals daily; pet owners in affected Texas counties and southern New Mexico should check for wounds; contact a veterinarian immediately if NWS is suspected

    Who Faces the Greatest Risk?

    • Livestock producers in South Texas and southern New Mexico counties — particularly those with cattle, sheep, and goats on extensive rangeland
    • Pet owners in the affected region, particularly owners of dogs and cats that spend time outdoors or that may have wound exposure
    • Wildlife (deer, feral hogs, exotic game) that serve as unmanageable host populations
    • Newborn animals, whose umbilical area is a common wound site for initial NWS infestation
    • Animals with any wound, cut, or body opening that has not been properly cleaned and treated

    Symptoms and Warning Signs to Watch For

    On livestock and pets:

    • Draining or enlarging wounds — especially wounds that do not heal normally
    • Signs of unusual distress or pain in an animal with a wound
    • Small, cream-colored larvae (maggots) visible in or around body openings — including the nose, ears, genitalia, and navel of newborns
    • Animals shaking their heads, rubbing against fences, or scratching excessively at wound areas
    • Foul-smelling discharge from a wound

    Infestations progress rapidly. An animal showing these signs should receive immediate veterinary attention. Without treatment, NWS can kill a full-grown animal within one week.

    What You Can Do Now

    • Inspect livestock and pets daily in affected Texas and New Mexico counties — particularly any animal with a wound, cut, or recent surgery.
    • Treat all wounds promptly with an approved insecticide or wound care product. Ask your veterinarian which FDA-authorized products are appropriate for your animals — multiple EUA products are now available for cattle, horses, dogs, and cats.
    • If you suspect NWS in an animal, do not wait. Contact your veterinarian immediately and report to the Texas Animal Health Commission (1-800-550-8242) or USDA APHIS.
    • Do not move animals out of the quarantine zone without authorization from TAHC.
    • Pet owners whose dogs or cats spend time outdoors in affected counties should inspect animals after outdoor time and keep wounds covered and treated.

    Cost and Access: What Patients Should Know

    The USDA Food Safety and Inspection Service confirms that the U.S. meat supply is not at risk — screwworm does not infest meat, and affected animals would be identified before entering commerce. Consumer food safety is not a concern in this outbreak.

    Veterinary treatment of confirmed NWS cases is covered by standard livestock health insurance in most cases. For producers concerned about coverage, the USDA’s Risk Management Agency provides livestock risk protection programs. Small-scale and hobby farm owners without commercial policies should contact their county Extension office for guidance on treatment costs and emergency assistance resources.

    What Happens Next

    USDA is continuing sterile fly releases, which represent the primary long-term eradication strategy. The 18-to-24-month timeline to full eradication capacity means this will be an ongoing management challenge throughout the rest of 2026 and into 2027.

    Updated case counts and quarantine zone maps are available at Screwworm.gov. MedicalDaily will report on any expansion of the quarantine zone, new confirmed cases in additional states, or any confirmed human infestations.

    The Bottom Line

    New World Screwworm has returned to the United States for the first time in 60 years. The 16 confirmed animal cases are almost certainly a fraction of the true infestation, and the multi-year eradication timeline means ranchers, pet owners, and veterinarians in affected regions of Texas and New Mexico face a sustained public health challenge. The food supply is safe. Human risk remains very low. But animal owners in the quarantine zone need to act now — inspect daily, treat wounds immediately, and report any suspected infestation without delay.

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  • ‘Flesh-Eating Maggots’ Back in the US After 60 Years – But Can the Deadly Screwworm Spread Between People?

    ‘Flesh-Eating Maggots’ Back in the US After 60 Years – But Can the Deadly Screwworm Spread Between People?

    ‘Flesh-eating maggots’ may sound like something from a horror movie, but they have just made a shocking comeback in the United States for the first time in nearly 60 years.

    Health officials in Maryland, alongside the US Centers for Disease Control and Prevention (CDC), confirmed that a traveller had been infected with the New World screwworm after returning from Central America.

    Confusion remains over whether the individual had travelled to El Salvador or Guatemala, but one thing is clear: the parasite is back on American soil.

    Panic has spread almost as fast as the news itself, leaving many to ask the same chilling question: is this gruesome maggot infestation contagious?

    Is the Flesh-Eating Screwworm Contagious?

    The short answer is no.

    Unlike flu or COVID-19, screwworm infestations cannot pass directly from person to person or even from animal to animal.

    Experts from the Center for Food Security and Public Health explain that the parasite spreads only when female flies lay eggs on open wounds or natural body openings.

    In other words, it is always the fly that carries the danger. A sore or cut attracts the insect, which deposits hundreds of eggs.

    These hatch into larvae that feed on living tissue, creating the illusion of contagion when multiple hosts in the same area are affected.

    How the Flesh-Eating Parasite Invades the Body

    According to the CDC, a single female screwworm fly can lay up to 3,000 eggs during her short life. Even the smallest scratch, insect bite, or a newborn’s umbilical wound can be enough to attract the parasite.

    Within hours, the larvae burrow into the flesh and begin consuming living tissue—unlike ordinary maggots, which feed only on dead matter.

    Left untreated, the wound enlarges as more flies are drawn in. In livestock, infestations can cause extreme suffering and even death. In humans, they are rare but potentially life-threatening if not treated quickly.



    Symptoms of Flesh-Eating Maggots to Watch Out For

    The CDC warns of several tell-tale signs of screwworm infestation:

    • Painful or enlarging wounds that fail to heal
    • Bleeding or foul-smelling sores
    • Visible maggots in open wounds
    • A sensation of movement under the skin or inside nasal, oral, or eye cavities

    While terrifying, most infestations can be treated successfully if caught early.

    Treatment: The Gruelling Process of Removal

    Treatment is unpleasant but effective. Every larva must be removed manually, the wound disinfected, and the patient closely monitored for reinfestation. No single medication can eliminate screwworm once it takes hold.

    On a wider scale, the US Department of Agriculture relies on the sterile fly programme. By releasing sterilised male flies, they disrupt the breeding cycle and suppress outbreaks.

    Agriculture Secretary Brooke Rollins recently announced plans for a new sterile fly facility in Texas—a move that now seems alarmingly well-timed.

    A Billion-Dollar Threat to America’s Cattle Industry

    The screwworm is not only a medical menace—it is also an agricultural disaster. The USDA estimates that an outbreak in Texas alone could cost $1.8 billion in cattle losses, veterinary expenses, and labour.

    With America’s beef industry already under pressure, confirmation of a human case has rattled ranchers and consumers alike.

    Should Americans Be Worried About Screwworm?

    ‘The risk to public health in the United States from this introduction is very low,’ Maryland health spokesperson Andrew Nixon told Reuters.

    Experts stress that the parasite does not spread casually between people. Prevention relies on proper wound care, sanitation, and avoiding fly exposure in endemic regions.

    Still, its reappearance after nearly 60 years is a sobering reminder: globalisation and climate shifts are making it harder than ever to keep old enemies at bay.

    Originally published on IBTimes UK

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  • U.S. Halts Animal Imports From Mexico As Flesh-Eating New World Screwworm Sparks Alarm

    U.S. Halts Animal Imports From Mexico As Flesh-Eating New World Screwworm Sparks Alarm

    The New World screwworm, a parasitic fly that harms both cattle and humans and was once eradicated from the U.S. after more than three decades of effort, is raising new concerns amid an outbreak in Mexico. In response to the looming threat, the U.S. Department of Agriculture (USDA) has announced a halt on imports of cattle, bison, and horses through the southern border.

    The New World screwworm produces larvae that feed on the flesh and blood of livestock, pets, wildlife, birds, and, in some cases, humans, causing painful infestations that can lead to potentially fatal damage to their hosts. It was eradicated in the U.S. in 1966 after billions of dollars were spent on an operation that involved releasing hundreds of millions of sterile adult flies, which would mate with wild females and ultimately prevent them from laying viable eggs.

    The recent threat emerged after the maggot fly was detected on remote farms in Mexico with minimal cattle movement, reaching as far north as Oaxaca and Veracruz, about 700 miles from the U.S. border.

    “Due to the threat of New World Screwworm, I am announcing the suspension of live cattle, horse, & bison imports through U.S. southern border ports of entry effective immediately. The last time this devastating pest invaded America, it took 30 years for our cattle industry to recover. This cannot happen again,” the USDA Secretary, Brooke Rollins, announced in an X post.

    The first case of infestation in Mexico was reported to the U.S. in November 2024, following which the USDA shut down the border for live animal trade. Trade resumed in February 2025, after the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) and Mexican authorities put in place a thorough inspection and treatment process to safely manage animal movement and reduce the risk of New World screwworm.

    The USDA announced that APHIS is deploying sterile flies by air and on the ground at key sites, focusing on southern Mexico and other parts of Central America.

    “The protection of our animals and the safety of our nation’s food supply is a national security issue of the utmost importance. Once we see increased surveillance and eradication efforts, and the positive results of those actions, we remain committed to opening the border for livestock trade. This is not about politics or punishment of Mexico, rather it is about food and animal safety,” Secretary Rollins said in a news release.

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