Bird flu virus found in cow’s milk poses treatment challenges as common antiviral medications show limited effectiveness, according to a new study published in Nature Microbiology.
Scientists at St. Jude Children’s Research Hospital have discovered that FDA-approved influenza medications may not successfully treat severe infections caused by the H5N1 avian influenza virus currently circulating in dairy cows across the United States.
“Our evidence suggests that it is likely going to be hard to treat people severely infected with this bovine H5N1 bird flu strain,” said the study’s corresponding author Dr. Richard Webby from St. Jude’s Department of Host-Microbe Interactions.
The research team tested two commonly prescribed antiviral medications – baloxavir (Xofluza) and oseltamivir (Tamiflu) – against the H5N1 virus in preclinical models. Their findings revealed that while baloxavir generally performed better at reducing viral levels, neither medication consistently provided effective treatment.
“In general, baloxavir caused a greater reduction in viral levels than oseltamivir, but neither was always effective,” noted first author Dr. Jeremy Jones.
The study highlights that the effectiveness of treatment depends significantly on how someone becomes infected. Researchers examined three primary infection routes – through the eyes, nose, and mouth – which are the most common ways people contract the virus.
Infections acquired through drinking contaminated milk (oral route) resulted in the most severe cases and were the most difficult to treat with current medications. However, baloxavir showed better results when treating infections that occurred through eye exposure – an important finding since this appears to be how many dairy workers are becoming infected.
In Nepal, where avian influenza outbreaks have previously occurred in poultry, these findings raise important considerations for public health officials. The country’s agricultural sector, which includes small-scale dairy farming in many regions, could be vulnerable if the virus were to spread to South Asia.
Dr. Rajendra Bohara, a veterinary specialist in Kathmandu, notes, “Nepal’s traditional farming practices often involve close contact between humans and livestock. Many rural families keep a few dairy cows and consume milk directly from their animals, sometimes without proper pasteurization.”
Public health experts in Nepal emphasize that the findings underscore the importance of strengthening surveillance systems, particularly in regions bordering countries where avian influenza has been detected in livestock.
With treatment options showing limited effectiveness, prevention emerges as the critical approach to protecting public health.
“Instead, reducing infection risk by not drinking raw milk and reducing dairy farm workers’ exposures, for example, may be the most effective interventions,” Dr. Webby emphasized.
Health authorities recommend several preventive measures:
- Avoid consuming unpasteurized milk or dairy products
- Ensure proper pasteurization of all milk before consumption
- Implement enhanced biosecurity measures for dairy workers
- Use appropriate personal protective equipment when handling potentially infected animals
- Establish regular testing protocols for dairy cattle
The ongoing H5N1 avian influenza outbreak in the United States has already infected more than 60 people through dairy exposures. While human infections remain relatively rare, the virus’s presence in cow’s milk represents a concerning development in the evolution of avian influenza.
Most infections have occurred through occupational exposure, such as dairy workers experiencing splashes or inhaling aerosolized particles containing the virus.
Health officials continue to monitor the situation closely while emphasizing that properly pasteurized milk remains safe for consumption.
As research continues, these findings highlight the importance of prevention strategies and the need for developing more effective treatments against emerging influenza threats.