Bird flu begins to spread to humans as health officials scramble to protect people and livestock

Those warnings proved prophetic. And the federal Centers for Disease Control and Prevention (CDC) now finds itself not only trying to slow the spread of the virus, but trying to play catch-up with testing methods that have been largely resisted by U.S. farmers. .

The question now is whether new interventions can prevent mass human-to-human transmission of this strain. Because for some experts, it's only a matter of time.

“There will be an avian influenza pandemic,” former CDC Director Robert Redfield bluntly predicted in a book. tv interview In June. “It's not a question of if, but more of a question of when…When a virus acquires the ability to attach to human receptors and is transmitted from person to person, that's when a pandemic occurs. be.”

a CDC investigation The article, released Thursday, did little to allay those concerns. The report found that a significant proportion of H5N1 infections were undetected among dairy workers who worked on farms raising cows that tested positive for the virus last summer. Of the 115 farmworkers who took blood tests in Michigan and Colorado, eight had evidence of recent infection in the form of antibodies, but only half could recall having symptoms. . “Officials said all eight people were milking cows or cleaning milking equipment.

Among other things, the results suggest that many more U.S. farmworkers may be unknowingly infected with the virus or have already been infected, and experts say that federal and state health authorities need to proactively offer testing and strengthen personal protection measures. We provide equipment (PPE) to people wearing boots on the ground at U.S. dairy farms and poultry farms.

“This generally confirms what we knew: more people were infected on farms than the official tally. The serology confirms that,” Johns said. says Amesh Adalja, a senior fellow at the Hopkins Center for Health Security. “That's why many of us want more aggressive serological testing on farms to understand the extent of infection and better understand the risks the virus poses. .”

inside press conference CDC Principal Deputy Director Nirav Shah said Thursday that there is “nothing in the new data that raises concerns about human-to-human transmission” and that the CDC believes the risk of the virus to the general public remains low. He added that

But in the UK, authorities have already raised the risk level for the bird flu virus from 2018. Medium to high. And in the United States, human H5N1 infections have occurred in California and Washington. rising. Nationally, 46 Human cases have been documented and confirmed During the 2024 outbreak, cases in Missouri were included. No known exposure So far, the two main sources of exposure have been either cattle or poultry. All experienced mild symptoms, including conjunctivitis and cough, and none were hospitalized.

Since the beginning of this year's H5N1 outbreak, federal and state officials have struggled to adequately test farms and farm workers. The reasons for this are manifold, but include farmers fearing their operations will be curtailed if a positive case is confirmed, and many migrant workers unwilling to interact with government officials, much less undergo blood tests. This includes the fact that they do not want to take the risk of getting tested. If you stay home from work and test positive, you won't get paid.

The CDC does not have the authority to mandate testing, but discovery If there are no symptoms or the symptoms are so mild that you don't notice them, Even if people who have studied bird flu and other similar viruses for years wouldn't be shocked to learn that some people didn't know they were infected, government and local It will likely elicit stronger proposals from health authorities.

“I don't think any of this is particularly surprising,” said Richard Webby, an infectious disease researcher at St. Jude Children's Research Hospital in Memphis and director of the World Health Organization Collaborating Center for Animal and Animal Influenza Ecology. say. bird.

Webby is responsible for almost all infectious diseases. However, asymptomatic infections can occur, especially in respiratory infections. “Absolutely expected.'' But the ability of H5N1 to spread silently from individuals who don't know they're infected could pose its own problems. And while there is no record of human-to-human transmission yet, experts fear the worst if it happens.

“I don't think we can predict that H5N1 will be the cause of the next pandemic, but it is certainly possible that avian influenza viruses will be the cause in the future,” Adalja said. “And I think we have to get it right this time. We like to think of this as a trial, even if we didn't manage to cause a pandemic, but from a trial standpoint, I think we're going to have to deal with this virus. We're not really doing great things.”

The CDC on Thursday recommended that farmworkers exposed to significant avian influenza get tested for H5N1, regardless of whether they have symptoms. This could be an important step as the traditional flu season begins and it becomes more difficult to distinguish one virus from another.. “The best way to limit the spread of the virus is to test, identify, treat and isolate as many infected humans as possible, as quickly as possible,” Shah said.

The agency is also calling for the antiviral drug Tamiflu to be made available to workers at high risk of contracting H5N1-infected animals, especially those who are not wearing appropriate personal protective equipment. Finally, the agency updated its recommendations to prioritize more PPE for people working in high-risk activities, such as milking parlors and poultry slaughter operations.

The California Department of Public Health has already Decentralized PPE as well as dairy farms and their workers, as in several other states. However, like other health organizations, staff cannot be forced to wear them. Anecdotally, this is a problem across the country, as workers often avoid gear in hot, stifling environments.

Separately report On Thursday, dairy farm workers in Colorado confirmed that the hot, humid conditions in milking parlors can make wearing respirators and masks uncomfortable. This can lead to fewer protected workers, especially during the summer months. And even for people wearing masks, it's not uncommon for PPE to deteriorate if they come into contact with contaminated milk or animal waste.

That creates a dangerous combination of situations. In many cases, workers are working unprotected in close proximity to infected dairy cows, and the route of infection can be as simple as splashing contaminated milk during the milking process. Researchers say this is precisely why health organizations need to double down on PPE education and provision.

“It's probably going to be difficult to use this PPE in large quantities,” Webby said. “But I think it's (important) to get that message across so at least the individuals who are at risk understand that there's a risk and that their PPE will probably help protect them.” We understand that even if it's not always wearable, it's better than nothing. And what's important is the messaging.”

In the early months when the H5N1 virus marched through American dairy and poultry farms earlier this year, such messages were virtually non-existent. At one point in June, Secretary of Agriculture Thomas Vilsack reportedly told scientific experts about bird flu, “Bird flu is just going to burn out.” vanity fair.

Now, health officials and the agencies they lead are scrambling to find ways to protect both people and livestock from the virus, which is already present. 446 dairy herds in 15 states and more 100 million birdsIn addition to recorded human cases, it occurs primarily in commercial poultry. Bird flu has been reported Mortality rate 52% The spread of infection in Europe since 2002 is a stark reminder of the dangers. Only by significantly ramping up prevention, testing, and treatment efforts, and with full public transparency about the results of those efforts, will it work.

Adalja and some other experts believe that this subtype of H5N1, which is prevalent in dairy cows in the United States, is not as severe in humans as other clades. But “the concern is the fact that this has been allowed to happen,” Adalja says. “This is something many of us on the ground have been talking about doing more proactively for months.”

The sound of the clock hands is getting louder.