Bird flu spread from cows to people. Now California advocates want more farmworkers to get tested

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In the heart of California’s dairy country, workers equipped with respirators, protective masks and gloves are battling one of the largest bird flu outbreaks in history. California has reported 16 human cases of bird flu this month, and worker advocates say the state is not doing enough to protect dairy workers.

According to the California Department of Public Health, only 39 people have been tested for H5N1, a strain of bird flu that affects cattle herds. Confirmed cases of sick workers in California account for nearly all the cases of cattle-to-human transmission in the country, according to the Centers for Disease Control and Prevention.

Human cases in California have been mild and there have been no hospitalizations, officials said. Sick workers reported flu-like symptoms in addition to conjunctivitis. There have been no reported cases of person-to-person transmission of the virus and the risk to the general population is low, state health officials said.

The current avian influenza surveillance strategy places much of the responsibility on farmers for self-reporting illnesses among animals and employees, which is problematic, said Elizabeth Streiter, a spokeswoman for the United Farm Workers.

“Workers are actively avoiding testing, I can assure you,” Strater said. “We have heard directly from the farmworker and veterinarian communities that they are seeing that there are sick workers.”

Workers, who are often low-income, cannot afford a 10-day isolation period without pay if they test positive, Strater said.

Millions of poultry have been culled since the virus first spread on California farms two years ago, and this year the highly contagious virus spread to cattle, posing a new threat to those who work with the animals.

Authorities have confirmed avian influenza infections on 178 California dairy farms since it first appeared in August, and there are no signs of the infection among cows slowing down, according to the state Department of Food and Agriculture. It is believed that transmission of infection from cows to humans occurs through close and prolonged contact with sick animals.

“The most alarming thing we have is how little data we have,” Strater said. “Hundreds of herds have tested positive and the number of people tested is in the dozens – this is a problem.”

Dr. Erica Pan, the state health department’s chief epidemiologist, said about 5,000 people have been tested for avian flu since February as part of routine flu monitoring.

The difference between testing for bird flu and COVID-19, which requires extensive surveillance, is that an eye swab must be taken, and this must be done by a doctor, Pan said.

“It’s about looking for symptoms and then testing for them, rather than testing people without symptoms,” Pan said.

California distributes PPE against bird flu

State and local health departments are focused on distributing protective equipment and training workers how to use it, Pan said. More than 1 million pieces of PPE have been distributed to local health departments and farms, according to the state health department.

The state also distributed 5,000 doses of seasonal flu vaccine to farmworkers. Although this vaccine will not protect against avian influenza, it reduces the likelihood of severe co-infection.

KFF Health News reported last week that farmers in other states have refused to cooperate with local health departments and disease researchers.

Tricia Stiver Blattler, executive director of the Tulare County Farm Bureau, said she had not heard of any cases in which local employers refused to cooperate with authorities.