There isn’t enough testing for bird flu among people and animals in the US, says Dr. Nirav Shah, deputy director of the US Centers for Disease Control and Prevention (CDC) – but he’s wary of drawing attention to the issue and damage the fragile trust among the population. farm workers and owners.
“We would like to do more testing,” Shah said. “We want to test not just symptomatic workers, but anyone on a farm who is exposed.”
But, Shah said, “right now we want to play a role where we build trust with farms and farm workers.”
For the general public, the risk is still low, the CDC says. But the risks are greater for farm workers who come into close contact with animals – and possibly for the people around them as well.
The CDC is preparing for the possibility that the virus could evolve and spread more easily among people, a spokesperson said report published on Wednesday.
Shah encouraged the use of personal protective equipment but stopped short of promising shots for farm workers, who are now most at risk of contracting and spreading H5N1, a highly pathogenic bird flu.
U.S. officials announced last week that a third person tested positive: a farm worker in Michigan who worked closely with sick cows.
Unlike the previous two cases, where conjunctivitis (or “pink eye”) was the only symptom, this patient experienced respiratory symptoms typical of flu – coughing, congestion, sore throat and watery eyes.
Shah was quick to point out that these symptoms do not mean the virus is changing. Symptoms like these are common in the 888 people who have tested positive for H5N1 since 2003.
“This virus, like many other viruses, can occur in more than one way. And for that reason we must remain alert and not alarmed,” he said.
But having respiratory symptoms means the individual has more opportunities to pass the virus to other people, he said, making monitoring and testing even more important than before.
Yet only 44 people have been tested in 2024, according to to the CDC.
Although officials believe cases are likely flying under the radar due to the lack of testing, they are closely analyzing data from flu monitoring systems and no red flags have yet been observed. “We found no differences in markers, such as emergency department visits, in areas with affected herds compared to areas without affected herds,” Shah said.
“Our flu infrastructure is strong, and it is remarkable to discuss the ways in which it differs from our Covid infrastructure,” he said. Testing is available across the country, a good vaccine candidate for this strain is currently being produced and the virus monitoring system is already well established.
“That said, we would like to do more,” he continued.
Some states are now testing the blood of dairy farm workers to see how many people have antibodies against H5N1, which could give scientists a better idea of how much the virus is circulating. “We have conducted these studies on poultry (workers) over the years. We would now like to replicate them among dairy farm workers,” Shah said.
Officials have also expanded the ways people can be tested for H5N1, including eye swabs in test kits to check for conjunctivitis. These eye swabs can now be tested at local labs instead of being sent to the CDC.
“Now we are not waiting for these tests to be confirmed (by the CDC) before taking public health action,” Shah said.
H5N1 continues to spread among farms, including poultry farms, with 4.2 million egg-laying chickens killed on a farm in Iowa after the virus was discovered.
In Idaho, alpacas tested positive on May 16 after an outbreak among poultry on the same farm – a sign that the highly pathogenic flu may be spreading from cows to poultry to other livestock, potentially causing mutations.
The second person to test positive in this year’s US bird flu outbreak showed a mutation that could make the virus spread more among mammals. genetic sequencing revealed.
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No genomic analysis of the third case has been announced yet.
While the U.S. Department of Agriculture announced an additional $824 million in funding to protect livestock last week, health officials have not announced any additional funding for this outbreak beyond the $101 million for the CDC and the Food and Drug Administration (USDA). announced in May.
Part of the USDA funding includes up to $2,000 per month to farms to provide personal protective equipment, or PPE, such as N95 respirators, face shields and goggles.
The CDC has asked states to distribute personal protective equipment to farmworkers, both from their existing stockpiles and from the strategic national stockpile.
“Fortunately, there is quite a bit of personal protective equipment available. Now the task is to connect those who have PPE with those who need it,” Shah said.
But officials are aware of the inherent difficulties of wearing something like an N95 mask while working on a farm — from the wet nature of the dairy farm to the summer heat.
“We want our workers to have maximum protection, while at the same time not putting their health and safety at risk by overheating,” Shah said.
U.S. officials have ordered 4.8 million doses of an H5N1 vaccine that they say is a good fit for the strain. Flu vaccines take several months to create, and new formulations like this then go through regulatory processes for authorization or approval.
Officials have shied away from saying who could be prioritized for the vaccines.
“There is no recommendation at this time to vaccinate farmworkers,” Shah said. “Of course there is discussion about it. As scientists, as scientific organizations, we are always discussing what will happen next and evaluating the pros and cons.”
Shah emphasized the importance of community trust in public health, especially as H5N1 is an emerging disease in livestock. For example, poultry farmers have built relationships with officials and regulators over decades of bird flu outbreaks.
Trust is “the most important tool you have in your toolbox during an outbreak,” Shah said.
“When H5 became a phenomenon in the poultry industry, it wasn’t overnight that poultry business owners, operators and employees were willing to work with public health authorities – it took time for that relationship to develop,” said Shah. “The same thing is happening here.”
That means being clear about what testing does and does not entail, and ensuring employee privacy, he said.
“It’s not something that happens overnight, but we have made progress with farms and farm owners. We want to continue that, rather than trying to overplay our hand and destroy the trust we have created so far.”