TIPTON, Calif. — It’s a late fall morning and hundreds of cows — black and white splattered Holsteins and cappuccino-colored jerseys — roam around the San Joaquin Valley Dairy in America’s largest milk-producing state. .
Nearby, workers herded some of the animals onto a carousel in the farm’s milking parlor and quickly installed pumping equipment. The machines whirred as the cows were whisked in a leisurely arc to the exit of the parlor, where they were disconnected from the milk hose and sent on their way.
The scene seemed completely unremarkable, except for the fact that five days earlier, the H5N1 avian influenza virus that had plagued California dairy herds for the past three months had been confirmed on the farm. Dozens of cows were sick and their owners expected the number to rise, but none of the farm’s workers were wearing personal protective equipment and vehicles coming from outside the property showed no concern. He came in and out without doing anything.
As H5N1 avian influenza infections increase on California dairy farms, cow deaths are becoming more common in some parts of the Central Valley.
(Thomas Obare/For the Times)
The farm is just one of more than 400 California operations with confirmed H5N1 outbreaks, but interviews with Central Valley dairy farmers and dairy workers, and U.S. Disease Control Recent research by the Control Center suggests that the virus may be an H5N1 infection. It is more prevalent among the population than official CDC numbers suggest. Authorities have urged dairy farms and workers to take precautions to prevent the spread of infection, but there is little evidence that the warnings are being heeded.
No expert says H5N1 avian influenza will become the next global pandemic, and government health officials say the virus poses a low risk to the public. But some experts warn that nearly all the conditions necessary for the virus to undergo threatening mutations now exist on many dairy farms. Close unprotected contact between humans and animals. A general failure to take threats seriously enough. And human flu season is approaching.
This particular clade of H5N1 viruses (2.3.4.4b) first emerged in North America in late 2021, and has since infected more than 600 dairy herds in 15 states, hundreds of millions of wild and domestic birds, and at least 48 infected several mammals. Species such as dolphins, seals, cats, and dogs.
“We’re in a virus soup, which means it’s all around us at the moment,” said the scientist at the Argentina-based One Health Institute at the University of California, Davis. Wildlife veterinarian Dr. Marcela Uhart recently spoke at a symposium held by Georgetown Law’s O’Neill Institute. . (11/15) “This virus is widespread among mammals and birds, but as far as we know, some of them are not showing signs of disease.”
In October, The Times visited Tipton, a dairy town in Tulare County, and spoke with several residents, including Elodia Ibáñez, who found that the number of human cases reported in California was lower than in mid-October. There used to be 16 people, but now there are 23 people. Too low. She said her husband, a dairy worker, told him that two of his co-workers had red and swollen eyes but were continuing to work despite exhibiting symptoms of bird flu.
“They knew that cows were suffering from this disease, and many cows were dying. But the president was concerned about the cows, not the workers,” Ibáñez told the Times. spoke. “They never said I had to go to the doctor to get tested.”
She says many people continue to work because they feel they have no other choice. “Despite saying there are laws to protect them, there are still a lot of people who are afraid…They are afraid of losing their jobs.”
Anthony, also a Tipton resident, said he was willing to talk but did not want to give his last name. He has family members who work on dairy farms and was afraid that speaking out would affect their employment.
“My father and uncle heard that there was an outbreak at a dairy farm,” Anthony said. He said his father and uncle are taking steps to ensure their safety, but many workers likely don’t report getting sick because they don’t want to get in trouble.
“Some of them are in the country illegally. They depend on that job and they don’t want to jeopardize it,” he said.
In early November, the CDC released the results of a study that looked at H5N1 antibodies in the blood of dairy workers in Michigan and Colorado. The agency collected blood samples from 115 people. Eight people, or 7%, had antibodies. Only three dairy workers in these two states have been positively confirmed to have the disease: one in Colorado and two in Michigan.
What concerns infectious disease and health experts is the blindness and ignorance about the virus’s reach.
And as human influenza season approaches, conditions become increasingly ripe for large-scale “spillover” as infected wild birds continue southward down North American highways and resting in lakes, ponds, farms, and backyards across the country. Experts are concerned that event.
Whether it’s avian influenza, human influenza viruses, or coronaviruses, viruses evolve, adapt, and mutate when given the opportunity to spread within and between organisms. In some cases, these mutations have little effect on the ability to communicate between organisms or can cause severe disease. But sometimes it does.
Additionally, avian influenza viruses can find and exchange genetic material with other circulating influenza viruses (human, swine, or other avian influenza), creating new “superflus” that are easily transmitted between humans. There are also concerns that it may result in The host is either critically ill or has immunity to the antiviral drugs used to treat infected patients.
In the 1970s, when our understanding of the influenza virus was still evolving, Robert Webster, a researcher at St. Jude Hospital in Memphis, Tennessee, conducted experiments at the U.S. Department of Agriculture’s Plum Island Research Station off the coast of Long. I did it. island.
He put the human influenza virus (H3N2) into one pig and the swine influenza virus (H1N1) into another pig. He then put the two pigs in a pen with four other pigs. Seven days later, he and his team detected the reclassified viruses, H3N1 and H1N2, in one of the other pigs.
Viruses swapped genes and created new combinations.
Jersey cows drink water at sunrise.
(Thomas Obare/For the Times)
Research by Webster and colleagues found that some of the more troublesome influenza pandemics in history were the result of this type of reassortment. For example, the 1918 influenza pandemic, which killed about 50 million people worldwide, is thought to be a combination of avian influenza and human influenza.
The same thing happened in 2009, when the human and swine influenza genes swapped, leading to a major H1N1 swine flu epidemic that killed about 500,000 people.
There is already evidence that this virus is exchanging genes. Birds migrating south from the Arctic now carry slightly different variants of H5N1, called D1.1 or D1.2, that have changed the interpretation of some viral segments of influenza. .
It is this strain that left a Canadian teenager in critical condition in a British Columbia hospital. Health officials don’t know where or how the child picked it up, other than it didn’t come from cows or poultry. And it is not yet known whether it acquired the ability to move easily between people. However, early and early tests suggest that it may have acquired some new and creepy properties, including changes that make it more susceptible to infecting people.
Still, there is currently no evidence that H5N1 avian influenza (known as B3.13), which is prevalent among dairy cows and workers, has acquired the ability to move efficiently from person to person and cause severe disease. There is no evidence that it did. But with human influenza season approaching, the possibility is growing as retail customers may have been drinking infected raw milk.
In an effort to spread awareness among dairy farms, potentially lure workers into testing, and reduce the chance of this virus spreading through the population and acquiring potentially deadly mutations, the state health department Agriculture and worker safety experts held a workshop in Tulare. The event will be held at the Expo Center in late October in cooperation with Western United Dairies, a dairy industry organization.
Approximately 20 dairy workers and farmers attended the two-hour session. The session included presentations in English and Spanish and dozens of slides from various state agencies.
California state epidemiologist Dr. Erica Pan told the audience that her agency recommends personal protective equipment in the workplace and urged people to protect their eyes. She also urged the audience to stay informed about recommended vaccines and to avoid eating raw milk, undercooked beef and “especially ground meat.”
Eric Berg, CalOSHA’s deputy chief of health, research and standards, said farms under quarantine must have a no-go area for infected animals. He said workers must wear protective gear, including coveralls, gloves and “very important…eye protection and respirators indoors.”
Eduardo Mondragon sat near the front of the conference room, nodding as experts discussed safety measures for dairy workers. As the manager of several dairy farms, Mondragon had seen bird flu spread to the farms he oversees in Tulare County, leaving him and his co-workers tasked with caring for sick cows.
He said milk production was down as hundreds of cows became sick and about 12 died, but dairy owners provided protective equipment such as gloves and goggles, and workers were given protective equipment. He said he was used to wearing it every day.
Mondragon said the dairy reacted quickly to stop the spread of infection when cows started getting sick over the summer. His boss sent him to a seminar in Tulare to learn more about bird flu.
“We didn’t stop for weeks,” he said, with many workers working weekend shifts to care for the cows. “We coped well with the flu, so we didn’t lose as much because of it. Milk production does, but animals don’t.”
Mondragon knows that even though his dairy farm experienced the worst of the bird flu outbreak in the summer, not a single worker reported getting sick. He said his friends in the industry in other countries have not yet been affected to the same degree as Tulare County dairy farms.
After the seminar, Mondragon loaded boxes of N95 masks, face shields and goggles into his white pickup truck and took them to the site to share with other workers.
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