Avian influenza antibodies found in dairy workers in Michigan and Colorado

There may be more cases of bird flu in humans in the United States than we previously thought. Health departments in two states conducted blood tests of workers on dairy farms known to have hosted infected cattle and found that about 7 percent of them had antibodies to the disease. This included people who did not have any flu symptoms.

Since March, the avian influenza virus known as H5N1 has been circulating in dairy cows across the United States. yet, 446 cows In 15 US states, people have tested positive for the virus. Since April, 44 people In the United States, the United States has tested positive for H5 – the influenza subtype that includes H5N1. All but one of these cases occurred in workers on poultry or dairy farms infected with H5N1.

To better understand how many farm workers may have been infected with the virus, The US Centers for Disease Control and Prevention (CDC) has collaborated with state health departments in Colorado and Michigan to collect blood samples from 115 people who work on dairy farms with H5N1-infected cattle. All samples were obtained between 15 and 19 days after cows on the farms tested positive for the virus.

Nirav Shah At the CDC and colleagues, they removed seasonal influenza antibodies from samples before testing them for the presence of H5N1 antibodies. They found H5N1 antibodies in eight of the samples, or about 7 percent, indicating that eight of the workers had been infected with the virus. What’s more, four of the workers did not recall symptoms.

“This is critical because he has accepted this point [H5N1] Testing has largely focused on symptomatic workers.” Megan Davis At Johns Hopkins University in Maryland. “When workers do not know they are infected, they may inadvertently expose others in their communities to infection.”

H5N1 is poorly adapted to infect humans and is not known to be transmitted between people. Still, more than 900 people worldwide It is said that the virus has had a virus since 2003, and about half of them have died. Each of these infections provides the virus with the opportunity to develop mutations that may make it more dangerous for people.

“We in public health need to cast a wide net of who we offer testing,” Shah said at a news conference today. “Going forward, the CDC is expanding the testing recommendation to include workers who have been exposed [to H5N1] And they have no symptoms.”

The agency also recommends offering antiviral medications to asymptomatic workers who have high-risk exposure, such as those on dairy farms who may get raw milk on their faces. This way, if they contract the virus, less of it will be circulated within them, which in turn reduces the risk of spreading it to others. “The less room we give this virus to run, the less opportunities we give for change,” Shah said.

These data also highlight that many H5N1 cases go undetected — something public health officials have long suspected to be true. However, we cannot speculate about how many unidentified cases there may be “until we have more data,” Shah said.

The CDC is now analyzing an additional 150 blood samples collected from veterinarians who work with livestock. When these results become available, they should provide us with a clearer picture of how many cases may be slipping through the cracks, Shah said.

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