Bird flu has been found in dairy cattle in nine states, leading to more tests for cows, milk and beef, but tests of dairy workers who might be exposed are not yet routine.
Infected dairy cows can shed the virus in their milk, putting workers near the cattle at highest risk of becoming infected.
Food safety officials announced this week they are now testing beef, including ground beef from grocery stores, for the presence of the bird flu virus, which was found in dairy cattle for the first time in March. The meat tests are the latest effort by the U.S. Department of Agriculture to track and understand how the virus is spreading among livestock. But some experts worry the virus could soon begin to spread more widely among people working with sick livestock.
Seema Lakdawala, an associate professor of microbiology and immunology at Emory’s School of Medicine, said Friday that the greatest risk posed by the appearance of bird flu in dairy cows is for those who work with them. The risk posed is so great that she recommends personal protective equipment like what was used in the early days of the coronavirus pandemic.
“I would strongly encourage you to inform your readership that there is a high concern for H5N1 to spill over into dairy workers, given the high level of virus in milk from infected cows,” Lakdawala said. “To avoid numerous infections in humans, we need to implement practical measures to reduce the spillover to humans on dairy farms. This includes a face shield for workers, preemptive H5 vaccine (already licensed for human use) from the stockpiles, and a ‘stay-on-farm’ order for cattle to reduce the spread of the current outbreak.”
This version of bird flu — known as highly pathogenic avian influenza (HPAI) or by its scientific name of H5N1 — was discovered in a dairy farm worker on April 1. That case marked the first time a human had caught the virus from a mammal.
Since then, the Centers for Disease Control and Prevention has said the risk to people is low. The agency states that could change if they see more instances of the virus adapting to spread more easily from animals to people.
So far, officials with the CDC have not seen signs that the virus is changing to be more transmissible to people.
Jason McDonald, a spokesman for the CDC, said in an email to The Atlanta Journal-Constitution on Tuesday that the health agency has been working internationally and domestically on surveillance for bird flu infections in people for decades. But testing of dairy workers is not being done now unless they show symptoms of an infection.
“There is just one human case associated with this outbreak in cattle and that person had mild illness (conjunctivitis only) and has recovered,” he said. “There is no spread of this virus between people at this time. H5N1 is still largely an agricultural issue affecting animal health.”
Testing for people without symptoms of illness is not routine, McDonald said, “because most people who are infected with avian influenza A viruses have usually shown symptoms of illness.” He said the global standard for influenza testing is to test people with relevant exposures who are symptomatic, including those with conjunctivitis only, or acutely ill.
At a press briefing Wednesday, Dr. Demetre Daskalakis, director of the CDC’s National Center for Immunization and Respiratory Diseases, stressed anyone exposed to bird flu is monitored for 10 days. If, during that 10-day period, the person shows signs of illness, they are then tested.
Credit: TNS
Credit: TNS
According to the CDC, as of Tuesday, just 23 people had been tested for the bird flu virus in the U.S., while at least 44 people were being monitored after exposure to it.
When pressed for more specifics on the number of people monitored during the press conference, Daskalakis said the number is constantly changing and is over 100 people.
Georgia Department of Public Health said no one in Georgia has been tested or is being monitored for the virus.
Bird flu has been found in nearly three-dozen dairy herds across the country — but not Georgia.
While Georgia Milk Producers, an advocacy organization promoting Georgia’s dairy industry, lists 79 active dairy farms in Georgia with 92,000 dairy cows, it’s not clear how many dairy workers there are in the state.
Some workers might also be immigrants — a community that can pose a challenge to public health workers hoping to monitor for the virus in humans. Immigrant workers may have no health insurance and may be reluctant to report an illness to their employers or other authorities.
Gigi Pedraza is the executive director of the Atlanta-based Latino Community Fund, a nonprofit that helped low-income Latino and immigrant workers access COVID-19 vaccines during the throes of the pandemic. She said Friday that public health authorities must develop “linguistically appropriate and culturally appropriate” outreach campaigns to educate dairy workers about the bird flu and its symptoms.
Dairy workers may be hesitant to come forward and report symptoms or seek treatment because some immigrant workers feel safer in the shadows, and they fear a hospital visit could compromise their ability to stay in the country.
”Immigrant workers are afraid for lots of reasons. And it’s justified because authorities haven’t really made an effort to make sure folks feel protected, especially in an election year,” Pedraza said “So, in short, know-your-rights [campaigns] are important. And then we need to educate community health workers and hospitals that people do have rights and they should be treated, especially when it comes to a potential public health crisis.”
Studies are underway to determine if the current outbreak in dairy cows poses a health threat to consumers. The U.S. Food and Drug Administration is conducting its own study of 297 samples of retail dairy products from 38 states, and at the press conference Wednesday, Donald A. Prater, acting director of the Center for Food Safety and Applied Nutrition for the FDA said preliminary results of additional testing is showing that pasteurization inactivates the bird flu virus.
Two more studies will determine if particles of the bird flu virus is found in beef for sale in the nine states where dairy cows have tested positive, or in the muscle of dairy cows sent to slaughter, whose meat will end up in grocery stores. A third study looks at how cooking meat at different temperatures affects the virus.
Emilio Esteban, USDA’s under secretary for Food Safety said during a press conference Wednesday that samples of retail ground beef had been collected in states where the virus was found in cattle and that results of tests were still pending.
The FDA said earlier additional tests of milk showed that pasteurization killed the bird flu virus, just as Colorado became the ninth U.S. state to report an infected dairy herd. “These results reaffirm our assessment that the commercial milk supply is safe,” the FDA said.
Until last week when the Department of Agriculture announced a mandatory testing program for dairy cows moving across state lines, testing of cows has been voluntary and was focused on cows with obvious symptoms of illness.
News that became public on April 24 that remnants of the H5N1 virus were found in milk for sale commercially should not be worrying to consumers, Lakdawala said. “The presence of viral fragments in pasteurized milk is not surprising. Influenza viruses are very heat sensitive and the multiple steps within pasteurization are likely to inactivate the virus, but pieces of it will remain. These pieces are not infectious and do not pose a risk to humans for ingestion.”
The Associated Press contributed to this article.
This story has been updated to reflect information shared at a press conference Wednesday hosted by the USDA, CDC and FDA.
