TRACKING EMERGING VIRUSES – August 6, 2025 – BIRD FLU
“First came bird flu, which led to the culling of large swaths of the nation’s poultry flocks and the soaring egg prices that helped undermine President Joseph R. Biden Jr.’s re-election. Now, ranchers in Texas and officials at the Agriculture Department are raising the next alarm: the New World screwworm.
Texas livestock producers and ranchers fear the United States is ill-equipped to handle a potential outbreak of screwworm, whose incursion into the country appears increasingly likely. With beef prices already soaring, the screwworm, whose Latin name roughly translates to “man-eater,” is a real threat, to both cows and the cost of living for America’s meat lovers.
“If we wait, we lose,” Stephen Diebel, vice president of the Texas and Southwestern Cattle Raisers Association, told state lawmakers during a hearing in Austin earlier this month as he pleaded for intervention.
The screwworm, like the measles, may have been forgotten by many, but it’s not new. And like the measles, which has cropped up in Texas recently, screwworm was once all but eradicated from the United States.” (1)
“When viruses collide: Eight public health experts and two state health officials from Washington and California — two states hit especially hard by the outbreak — told POLITICO that the decision makes sense if the federal government’s case count is accurate. But they warned that things could shift quickly as the weather cools off. The seasonal migration of birds and the human flu season will increase the chance of a fall influenza-bird flu mash-up, which could make it more likely that bird flu will spread among humans, the experts warned.
“The most likely scenario is that someone will get infected with both H5N1 and a seasonal flu virus, and they will swap genes, and that reassortment could kick off the next pandemic,” said Jennifer Nuzzo, a professor of epidemiology and director of the Pandemic Center at Brown University School of Public Health.”
“We are going to see another influenza pandemic, and it could be much worse than we saw with Covid, and we’re not preparing for that at all,” said Dr. Michael T. Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota. “We have an opportunity with mRNA technology to make a vaccine much faster … and yet, if you look right now, we’ve cut all funding within the U.S. government for that type of work.” (2)
“The Centers for Disease Control and Prevention has ended its emergency response to the H5N1 bird flu and said Monday it will streamline future updates on the virus with routine reports on seasonal influenza.” (3)
“The federal government has paid California dairy farms more than $230 million to subsidize losses in milk production resulting from bird flu, records show, an amount that the dairy industry expects to climb higher as more claims for damages are processed.”
“Angela Rasmussen, a virologist at the University of Saskatchewan’s Vaccine and Infectious Disease Organization in Canada, said handing out subsidies to farms without trying to understand or investigate the practices they are using to quash the disease is a mistake.”
“What are they doing on the farms to prevent reinfection?” she said.” (4)
“The bird flu virus that has beset dairy farms since early last year may be spreading through the air in so-called milking parlors and through contaminated wastewater, as well as from milking equipment, scientists have found.
The Department of Agriculture has said that the virus spreads primarily from milking equipment or is carried by dairy workers and vehicles traveling between farms.
But in the new study, scientists found live virus in the air of milking facilities, suggesting that cows and farmworkers might have become infected by inhaling the pathogen. The virus may also spread by water used to clean cattle barns or contaminated with discarded milk.”
Infestations occur when a female fly lays eggs, between 10 and 400 at a time, on a fresh animal wound. Within a few hours, the eggs hatch into larvae that burrow and feed on the flesh. As the wound worsens, it attracts more flies, which lay more eggs. After about a week, adult screwworm flies can reproduce and begin the cycle all over again. The parasitic infection can kill a cow within two weeks if left untreated. There is currently no approved treatment.” (5)
“The findings support the need for multiple mitigations, including respiratory and ocular protection for farm workers, disinfection of milking equipment, treatment of contaminated milk and wastewater to inactivate the virus, and identification of infected cows, even those that aren’t showing clinical symptoms.” (6)
New study advances theory on why most U.S. bird flu cases have so far been mild, https://www.statnews.com/2025/07/23/h5n1-bird-flu-immunity-boosted-by-previous-influenza-a-infection/
This Boise lab used to ship bird flu samples to CO. Now it gets results in hours, https://www.idahostatesman.com/news/northwest/idaho/article311510560.html
“Several recent studies have found that those who caught seasonal flus or received flu vaccinations have low levels of antibodies against H5N1 avian influenza as well. The work may prompt changes to existing flu vaccines, potentially making them more effective against bird flu.
Health care workers and others who recently caught seasonal flu had antibodies that could glom onto H5N1 bird flu viruses taken from dairy cattle, researchers reported July 16 at bioRxiv.org. Some of those antibodies may block bird flu from infecting cells. Two strains of flu each account for roughly half of seasonal illnesses, but they affect potential H5N1 immunity differently. People who caught H1N1 seasonal flu had more antibodies aimed at bird flu than did those infected with the H3N2 strain.” (7)
1.Avian Flu Wiped Out Poultry. Now the Screwworm Is Coming for Beef., By Pooja Salhotra, https://www.nytimes.com/2025/07/28/us/politics/screwworm-beef-prices.html
2.Experts’ bird flu warning, By SOPHIE GARDNER and KELLY HOOPER, https://www.politico.com/newsletters/politico-pulse/2025/08/04/experts-bird-flu-warning-00491548
3.CDC winds down emergency response to bird flu, by Josephine Walker, https://www.axios.com/2025/07/07/cdc-winds-down-emergency-response-to-bird-flu
4.California dairy farmers got millions to cover bird flu losses. Critics say that’s part of the problem, By Susanne Rust, https://www.latimes.com/science/story/2025-07-28/ca-dairies-cash-in-on-usda-bird-flu-indemnity-payouts-220-million
5.Bird Flu May Be Airborne on Dairy Farms, Scientists Report, By Apoorva Mandavilli and Emily Anthes, https://www.nytimes.com/2025/08/04/health/bird-flu-airborne.html
6. Air, wastewater may play roles in H5N1 transmission on dairy farms, by Lisa Schnirring, https://www.cidrap.umn.edu/avian-influenza-bird-flu/air-wastewater-may-play-roles-h5n1-transmission-dairy-farms
7.You may already have some protection from bird flu, but don’t count on it, By Tina Hesman Saey, https://www.sciencenews.org/article/seasonal-vaccine-protect-h5n1-bird-flu
curated by Jonathan M. Metsch, Dr.P.H.
Clinical Professor of Environmental Medicine, Icahn School of Medicine at Mount Sinai