How the Messy Process of Milking Cows Can Spread Bird Flu How the Messy Process of Milking Cows Can Spread Bird Flu
The New York Times
On America’s large dairy farms, milking is a vast operation, and the potential for disease transmission is worrying, health experts say.
After bird flu hit the nation’s dairy farms, it spread with alarming speed. Since March, the virus has infected more than 700 herds in 15 states. It has also infected at least 58 people, nearly all of them farm workers. In recent months, cases in cows and humans have mounted especially rapidly in California, now the epicenter of the outbreak.
Initially, experts worried that the virus might be spreading through tiny, airborne droplets that cows exhaled.
But data strongly suggests that the virus, known as H5N1, has spread primarily through milk. It replicates quickly in the udders of infected cows, which produce milk with sky-high levels of the pathogen. Droplets of milk can splash into dairy workers’ faces, while milk-splattered equipment and vehicles can transport the virus from cow to cow.
Although pasteurization effectively inactivates the virus, the pathogen was recently detected in retail samples of raw milk in California.
Those findings, plus the rising number of human cases, have made experts nervous about the growing public health threat — and the potential ascension of Robert F. Kennedy Jr. to lead the Department of Health and Human Services. Mr. Kennedy is a vocal proponent and self-professed consumer of raw milk and has said that he wants federal researchers to take a “break” from studying infectious disease.
In theory, a virus that spreads through milk should be easier to control than one that floats invisibly in the air. But a look inside the modern dairy industry reveals that milk-based transmission is profoundly worrying. “Milk is hugely problematic,” said Seema Lakdawala, a virologist at Emory University.
