Almost from the beginning of the expansion H5N1 bird flu Among US farms and ranches earlier this year, experts and researchers warned that a critical delay in blood testing of exposed workers could lead to an underestimation of the potential transmission of the virus to humans.
These warnings have been prophetic. And the federal Centers for Disease Prevention and Control (CDC) is now not only trying to slow the spread of the virus, but is also grappling with testing methods that have been largely resisted by America’s farmers.
The question now is whether new interventions can deter massive human-to-human transmission of this strain, which some experts say is only a matter of time.
“We’re going to have a bird flu pandemic,” said former CDC director Robert Redfield bluntly. television interview in June “It’s not the point; it’s more a matter of when… When the virus gains the ability to attach itself to the human host and then go to the human, that’s when you’ll have a pandemic.”
A CDC study What was released Thursday did little to ease that concern. The report found that a significant percentage of H5N1 infections went undetected in dairy workers who tested positive for the virus last summer. Among 115 farmworkers whose blood was tested in Michigan and Colorado, eight had evidence of recent infection in the form of antibodies, but only half remembered having symptoms. “All eight were either milking cows or cleaning milking mechanisms, officials said.
Among other things, this result suggests that more American agricultural workers may be infected with the virus or may already be infected without knowing it; all the more reason, experts say, for federal and state health agencies to aggressively offer testing and enhanced personal protection. equipment (PPE) to those with boots on the ground on US dairy and poultry farms.
“This confirms what we generally knew: there are more people being infected on farms than the official count. The serology shows that,” says Amesh Adalja, a senior expert at the Johns Hopkins University Center for Health Security. “That’s because many of us have wanted more aggressive serological testing on farms to understand the extent of the infection and to better understand the risks that the virus poses (there).”
through A press conference on Thursday, CDC Deputy Director Nirav Shah said that nothing in the new data “raises concern about person-to-person transmission,” and that the agency believes the virus still poses little risk to the general public.
In the UK, however, government officials have already raised the risk level of the bird flu virus medium and high. And in the US, there are human H5N1 cases in California and Washington the rise. At the national level, 46 human cases have been documented and confirmed 2024 appearance, including one person from Missouri no known exposure cattle or poultry, the two main sources of exposure so far. All people had only mild symptoms, such as conjunctivitis or cough, and no one was hospitalized.
Since the start of this year’s H5N1 outbreak, federal and state agencies have scrambled to conduct adequate testing on farms and among farm workers. The reasons are many, but include the fact that farmers are afraid of curtailing their operations if positive cases are identified, and that many migrant workers do not want to interact with any government officials, let alone risk having or needing blood tests. stay home from work and don’t get paid if they test positive.
The CDC does not have the authority to mandate testing, though the discovery They can be asymptomatic or so mild as to be imperceptible prompted stronger suggestions from him and local health agencies, although those who have long studied bird flu and other similar viruses are not surprised to learn that some people did not know they had been infected.
“I don’t think it’s surprising,” says Richard Webby, a Memphis-based St. Jude Children’s Research Hospital infectious disease researcher and director of the World Health Organization Collaborating Center for the Study of Animal and Animal Influenza Ecology. the birds
Webby noted that with almost any infectious disease, but mainly of a respiratory nature, they are asymptomatic cases of infection “Totally planned.” But H5N1’s ability to spread silently from people who don’t realize they’re infected can cause its own problems. And while there is still no record of human-to-human transmission, experts fear the worst if and when it happens.
“I don’t think it’s a foregone conclusion that H5N1 will be the cause of the next pandemic, but it certainly will be a bird flu virus in the future,” says Adalja. “And I think we have to do well with this. Even if it can’t cause a pandemic, we want to think of it as a testing process, and we’re not doing really great things, from a testing perspective, with this virus.”
The CDC on Thursday recommended that farm workers with high exposure to bird flu be tested for H5N1 regardless of whether they have symptoms, a measure that can be important as the traditional flu season gets underway and it becomes harder to distinguish one virus from another.. “The best way to limit the virus’s running room is to test, identify, treat and isolate as many human cases as possible as quickly as possible,” Shah said.
The agency also plans to offer the antiviral Tamiflu to workers who had high-risk exposure to animals infected with H5N1, especially those who were not wearing proper PPE. Finally, the agency has updated its recommendations to prioritize more PPE for those in higher-risk activities, such as those working in dairies or poultry slaughtering operations.
The California Department of Public Health has already done so distributed PPE to dairy farms and their workers, like some other states. But like other health agencies, it cannot force workers to wear them. Anecdotally, this has been a problem across the country, with workers often ditching the gear in hot, stifling conditions.
In an extraordinary the report On Thursday, Colorado dairy workers confirmed that the hot and humid environments found in dairy parlors can make wearing respirators and masks uncomfortable. Especially in the summer months, this can mean fewer protected workers. And even among mask wearers, degradation of PPE is not uncommon when workers are near contaminated milk or animal manure.
It creates a dangerous combination of situations: often unprotected workers working in close proximity to infected dairy cows, where the path to infection can be as simple as being splashed with contaminated milk during the milking process. Researchers say that’s why health agencies need to double down on PPE education and provision.
“It can probably be difficult to use this PPE a lot,” says Webby. “But I think messaging (is important) so at least people at risk understand there’s a risk and they understand their PPE probably helps protect them. Even if it’s something they can’t wear all the time, anything is better than nothing. And messaging is the key.”
Such messaging was virtually absent in the early months of H5N1’s march through America’s dairies and poultry farms earlier this year. At one point in June, Agriculture Secretary Thomas Vilsack told scientific experts about the bird flu: “It’s going to burn itself out,” he said. Vanity Fair.
Now, those health officials and the agencies they lead are scrambling to find ways to protect both people and livestock against a virus that’s already infected. 446 milk groups in 15 states and more than 100 million birdsmostly commercial birds, apart from documented human cases. Bird flu news 52% death rate It’s a grim reminder of the stakes in Europe since 2002, and only prevention, testing and treatment efforts will work, along with full public transparency about the results of those efforts.
Adalja and other experts do not believe that this subtype of H5N1 circulating in US dairy cows is as serious as other clades in humans. But, “what is worrying is that this was something that was allowed”, says Adalja. “That’s what many in the field have been talking about for months about being more aggressive.”
The clock chimes louder.
