'Concerning' Bird Flu Study Finds Surfaces Contaminated for a Long Time
Published Jun 28, 2024 at 10:26 AM EDTScientists have issued a warning after bird flu viruses were found to remain active on hard surfaces for several hours, increasing their potential to infect people and other animals.
The findings are particularly concerning for dairy farmers as the virus was found to remain stable in unpasteurized milk on the metal and rubber components of commercial milking equipment.
Highly pathogenic avian influenza is an infectious viral illness that spreads primarily among wild and domestic birds. But the virus that causes bird flu can sometimes jump into animals, including dairy cows and, in some cases, humans.
A "multi-state outbreak" of the virus has emerged among dairy cattle since mid-March, according to the U.S. Centers for Disease Control and Prevention (CDC), and three cases have been confirmed in humans.
All cases so far have been among dairy workers who are exposed to infected cows.
"Dairy cows have to be milked even if they are sick, and it has not been clear for how long the virus contained in residual milk from the milking process remains stable on the equipment," Valerie Le Sage, a research assistant professor of microbiology and molecular genetics at the Center for Vaccine Research at the University of Pittsburgh School of Medicine, said in a statement.
To explore this question, Le Sage and colleagues at the University of Pittsburgh and Emory University created a lab environment to mimic the humidity and temperature of outdoor milking parlors in Texas. They then suspended particles of the H5N1 bird flu virus in milk and measured how stable they were on metal and rubber surfaces over an extensive period of time.
"Our data supports that milking equipment surfaces can stay contaminated for a long time," Le Sage said. "It is concerning that the virus in unpasteurized milk can remain stable for hours and potentially infect farmworkers or spread from animal to animal."
Le Sage added that the findings, published in the journal Emerging Infectious Diseases, highlight the importance of personal protective gear, like face shields and masks, for dairy and farmworkers as well as enhanced sanitization of milking equipment between cows.
These findings add to previous research by the FDA, revealing that one in five retail milk samples across the U.S. contain genetic traces of H5N1 viruses. While the majority of these genetic traces were not active, whole forms of the virus, studies like this underscore the importance of milk pasteurization amid the current outbreak.
The CDC also recommends the following actions to keep yourself safe from bird flu:
- Avoid direct contact with wild birds
- Report sick or dead birds to your local authority
- Avoid unprotected direct physical contact or close exposure to cattle
