It was inevitable that it would happen again: For the second time in two months, the United States has confirmed a case of bird flu in a dairy farmer who works on a farm with cows infected with H5N1. “The only thing that’s surprising is how long it’s taken for these new cases to become known,” said Steve Valeika, a veterinarian and epidemiologist in North Carolina.
The actual number of infected people is almost certainly much higher. Anecdotal Reports of Sick agricultural workers The virus is trickling in from all over the countries where it has been detected. Dozens of herds in nine statesThe federal government’s tally puts the number of infected at 1,000. Human and animal testing is limited, and cooperation from farms is still lacking. The gap between reality and what governments can measure means the world doesn’t know the full extent of the outbreak. It could also reduce experts’ ability to detect human-to-human transmission if it does occur one day. “I wouldn’t be surprised if we have a few dozen cases at this point,” Valeika said.
With federal guidelines still in place, the risk to the majority of the population remains low. EmphasizeBut that confidence is fading with “the threat to agricultural workers remaining elevated,” said Jennifer Nuzzo, director of the Pandemic Center at Brown University’s School of Public Health. Infectious diseases too often hit the most vulnerable in society the hardest. Now, the future of this virus depends on America’s ability to protect communities where health and safety are routinely disregarded.
Like this: First case Compared with previous reports of dairy workers contracting avian flu, this second report has at least one reassuring element: In both cases, frequent contact with infected dairy cows appears to have been the cause, resulting in mild illness. Eye symptoms only. (in Another US exampleBeginning in 2022, a man contracted the virus from poultry. Malaise The only symptoms reported are that H5N1 virus receptors in cow’s udders and human eyes are similar to those found primarily in birds, leading experts to believe these receptors provide an easy entry point for the virus. The virus still appears to be an avian pathogen; it would need to evolve further to fully infect humans. For most of the public, “we’re not worried about H5 right now,” Seema Lakdawala, a virologist at Emory University, told me.
But dairy workers have reason to be worried, Lakdawala added. parlor In dairy parlours, cows are strapped to a milking machine by their udders, the machine is turned on until it slows down the milking, and then when released, they are shaken off “at the cow’s eye level,” spraying the frothy liquid at passers-by, Lakdawala told me. It is not necessary to disinfect each animal.—And cleaning do The work often involves flushing with high-pressure hoses, which also atomize the milk. As workers attach the machines to each cow and manually regulate the initial flow of milk, they often have direct contact with the udders. Even if workers don’t get milk on their hands (though they will eventually touch their faces), they’re constantly exposed to aerosols, droplets, and sprays, Lakdawala says.
If there are infected cows, Many Exposure to the virus. Lakdawala’s lab has been studying how long H5N1 can survive on milky surfaces. Initial ResultsThe findings, which have not yet been published in a scientific journal, suggest that the virus can persist for at least one to three hours on the same types of plastics and metals commonly used in milking equipment. Lakdawala said this creates a clear route for the virus to move between animals, and also makes it a very easy way for humans to catch the virus. Improper disposal of milk Milk from infected farms may pose a risk of infection, especially if the cows are dairy cows, as they must be milked. Farm cat Lakdawala said the Agriculture Department recommends that all milk be heat-treated before disposal, but farms, especially smaller ones, may not have the necessary equipment or manpower on a consistent basis.
The CDC Urged agricultural workers Goggles, gloves, high-quality respirators, and other protective gear are recommended in these environments. But those recommendations can’t really be enforced, and it’s unclear how many farms are following them, or how many workers on those farms are. As the heat increases through spring and summer, Lakdawala notes, wearing such gear may become even more uncomfortable, especially in the muggy, cramped conditions where the most exposed people do the most work. Goggles and other tight-fitting eye protection are especially tricky to work with. “They get dirty quickly,” Lakdawala says. Workers can’t see what they’re doing through milk-spattered lenses.
Enthusiasm for cow and human testing Low On farms, managers and employees carefully consider the financial and personal risks they face if one of their cows is reported to be sick. And asymptomatic cows Probably responsible To a great extent Spread the wordThe USDA only requires the following inspections: Cow Subset They’re moving between states, which essentially means “the virus isn’t being detected before it can infect farmworkers,” Nuzzo said. CDC The UK government has said that “asymptomatic testing” for H5N1 is “not routinely recommended” and that there is no guarantee that people who have been in close contact with infected people will be tested for the virus. Such delays could allow the infection to smolder, past the point where treatments such as Tamiflu can be used to intervene and prevent infection from spreading to close contacts. The fact that this second case has been found does not mean that testing is sufficient. MichiganNuzzo said dairy farmers are being more proactive in testing their herds. He and Lakdawala say stockpiles of vaccines should be made available in bulk to farm workers while the risk is still high, but Federal Government Employees No injections offered yet(The USDA and CDC did not respond to requests for comment.)
These shortages are worrying for people battling less visible infections. But H5N1 could also exacerbate existing health disparities, especially among agricultural workers, Ann Sosin, a public health researcher at Dartmouth College, told me. If protecting agricultural workers is the top priority, “I think we’re failing,” Valeika said.
Researchers also aren’t sure how much risk an infected farmworker poses to close contacts. Other types of conjunctivitis are quite contagious, and Lakdawala says it’s possible for someone who has just rubbed their eyes to transmit the H5N1 virus by touching someone else’s hands and then touching their face. Experts are also concerned that eye infections could spread to other parts of the body, including the respiratory system, especially if the virus mutates in a way that allows it to adapt to receptors in the lungs. (Fortunately, a nasal swab from a Michigan dairy worker was found.) H5 virus negative.
The virus doesn’t appear to have yet reached that kind of spike. But influenza infections remain a problem for everyone. “If we can’t stop it in the most at-risk groups, the threat to the general public is only going to grow,” Sosin told me. H5N1 may not be transmitted from person to person. But even if it did, community transmission of the virus, which American society failed to adequately protect, would have helped it spread.