3 years ago, back then It is gradually spreading to the United Statesavian influenza virus Recently killed a man in Louisiana. For most Americans, it was a vague and distant threat. It has now spread and affected all 50 states. Over 100 million birdsmost of which are poultry. Herd of approximately 1,000 dairy cows It has also been confirmed that the virus is present. at least 66 Americans, most of them He became ill because he worked in close contact with cattle. There is no guarantee that a full-blown H5N1 pandemic will occur. The CDC has determined the risk of an H5N1 pandemic as follows:Moderate. “But this virus is fundamentally more difficult to manage than it was a few months ago and is now becoming a permanent danger to people.
That didn’t have to be a reality for the United States. “The experiment to see if H5 will be successful in the human population is happening right before our eyes,” said Seema Lakdawala, an influenza virologist at Emory University. “And we’re not doing anything to stop it.” The story of bird flu in this country could have been shorter. The number of cows involved may have been much smaller. The US simply chose not to write it that way.
USDA and CDC staunchly defended their response to H5N1, insisting that their interventions were appropriately aggressive and timely. And of course, governments cannot completely control the spread of infection. But experts outside federal agencies told me that H5N1 would have been a manageable enemy, at least compared to the most prominent infectious disease threats in recent memory. When SARS-CoV-2, the virus that caused the coronavirus pandemic, first infected humans, there was little to stop it. It is an entirely new pathogen that has invaded people who have no existing immunity, public awareness, testing, antiviral drugs, or vaccines to fight it.
Meanwhile, H5N1 is an influenza virus that scientists are studying Since the 1990swhen it was first detected in poultry in China. It has caused sporadic outbreaks among the population for decades. Researchers tracked their movements in the wild and studied them in the laboratory. The government is stockpiling vaccines against the virus and preparing effective antiviral drugs. And while this virus has proven capable of invading us and continues to evolve, “this virus is still very much an avian virus,” says Richard, director of the World Health Organization Collaborating Center for Influenza Ecology.・Mr. Webby said. Animals and birds taught me. They do not yet seem to have the ability to move efficiently among humans, and may never acquire that ability. Most human cases in the United States are associated with an obvious animal source and are not severe.
In other words, the United States may have eliminated the virus early on. Instead, government agencies tasked with responding to outbreaks and maintaining animal and human health initially refrained from mitigation strategies such as testing, surveillance, protective equipment, and isolation of potentially infected animals. . “We’re underutilizing the tools that are available to us,” said Carol Cardona, an avian influenza expert at the University of Minnesota. The virus is tearing through wildlife populations, decimating the nation’s poultry, spilling over into livestock, and beginning to infect farm workers. accumulated mutation This showed that adaptation to mammals was progressing, but the country remained largely silent.
When I asked experts if there was a clear tipping point in the outbreak, a point in time when it would be critical for U.S. leaders to intervene in a more coordinated manner, nearly all of them said the following: did. Late winter or early spring last yearWhen farmers and researchers first confirmed that H5N1 had entered the country’s cattle in the Texas Panhandle. This was the turning point. of jump It is thought that the virus was probably transmitted to cattle from wild birds. happened only once. It may have been impossible to prevent it. But once the pathogen enters the animal’s body, “we humans have a lot of control over it,” Lakdawala said. Authorities could have immediately halted the cattle transport and organized a careful and coordinated culling of the infected herd. The virus probably “never spread beyond Texas,” Lakdawala told me. Dozens of people may not have been infected.
This type of intervention would have at least given the public more time to provide information and protection to agricultural workers and perhaps develop a plan to strategically deploy vaccines. Cardona said it’s also possible that government officials purchased animals from the private sector to study the spread of the virus. “We could have figured it out,” she said. “By April or May, we would have known how to control it,” said Sam Scarpino, an infectious disease modeler and influenza researcher at Northeastern University.This slim window of opportunity is narrow but clear. The team is following closely. timeline He told me about the epidemic in America. In retrospect, he says, “Realistically, that was probably our window.” “We were too late.”
In contrast, the virus sped up. by AprilA human case was confirmed in Texas. By the end of June, H5N1 had infected herds in at least 12 states and more than 100 dairy farms. Less than 10 months after the U.S. Department of Agriculture first announced the dairy outbreak, the number of affected herds has increased. approaching 1,000— and those are the only ones known to authorities.
The USDA has repeatedly challenged that response as inadequate, pointing out that: atlantic ocean and Other publications He said he immediately began research this spring to monitor the movement of the virus through the dairy herd. “The Department of Agriculture’s slow response is patently false and seriously discredits the many scientists who worked on this study,” said Eric Deeble, USDA’s deputy assistant secretary for marketing and regulatory programs. said in an email.
And the mission of this institution was not an easy one. Not known to be a source of H5N1 infectionAnd dairy farmers never had to deal with such diseases. The best mitigation strategies were also commercially strong. The most efficient way to milk a cow is always to send a plume of milk droplets into the air. Disinfecting equipment is a hassle. Additionally, “the dairy industry is built around herd movement,” which is a surefire way to move infectious diseases, Cardona said. of Dairy worker population It also includes many undocumented workers, especially those who have little incentive to disclose their infection to government officials or to heed their advice. “There was a lack of trust,” especially at the beginning of the outbreak, Nirav Shah, the CDC’s principal deputy director, told me. “It’s not going to go away overnight.” While the situation is improving from the CDC’s perspective, Shah said this attitude continues to hinder efforts to equip farms with protective equipment and catch infectious diseases. admitted.
Last month, the Department of Agriculture announced that: new plan To combat H5N1, farms across the country are being urged to comply with milk testing requirements. But Lakdawala and others still criticized the strategy as too little, too late. Although USDA called the farm If infected herds are to be used to enhance biosecurity, implementation is up to the states. And even today, testing of individual cows is largely left to the discretion of the farmer. As a result, too few animals are tested, hiding the true spread of the virus, Lakdawala said.
The USDA plan also aims to eliminate the virus from the nation’s dairy herds, but it remains unclear exactly how many cows are affected or how the virus moves between hosts. This is a difficult task, as no one knows exactly what the situation is. “How do we get rid of something like this that’s so prevalent?” Webby told me. Eliminating the virus from cattle may actually no longer be an option. The virus also shows no signs of wiping out bird populations, which have historically been a source of infection in birds. more serious cases Examples of avian influenza detected in humans, including the deadly Louisiana case. “We’re really fighting a two-pronged battle,” Cardona said, as both birds and cows carry the pathogen.
Most of the experts I spoke to also expressed frustration that the CDC still does not provide avian influenza-specific vaccines to farmworkers. When I asked Shah about this policy, he noted that worker safety remains a “top priority” and defended the agency’s focus on protective gear and antiviral drugs. With no consistent severe disease occurring and no evidence of human-to-human transmission, “it’s not at all clear that vaccines are the right tools for that purpose,” he told me. told.
The influenza epidemic is in full swing and there is a shortage of farm workers. Any Influenza vaccination is one of the most important measures countries can take to limit the threat of H5N1. The spread of seasonal influenza will only complicate health authorities’ ability to detect new H5N1 infections. And each time a person who has already had seasonal influenza gets infected with bird flu, the viruses get a chance to exchange genetic material, potentially speeding up the adaptation of H5N1 to humans. Aubrey Gordon, an influenza epidemiologist at the University of Michigan, told me that’s her biggest worry right now. Lakdawala is already concerned that human-to-human transmission is occurring. The US just hasn’t implemented the infrastructure. Even if tests eventually confirmed it, she told me: “I’m not surprised.”
