A new study published by the US Centers for Disease Control and Prevention shows that the H5N1 bird flu virus is probably not detected in cattle in many parts of the country and can infect inappropriate veterinarians.
In the report of the morbidity and mortality of the health agency, a group of CDC researchers, the Ohio Ministry of Health and the American Assom. Bovin practitioners reported the results of an analysis they carried out on 150 cattle veterinarians or cows of 46 states and Canada.
They found that three of them had antibodies for the H5N1 bird flu virus in their blood. However, none of the infected veterinarians recalled to have had symptoms – including conjunctivitis or pink eye, the symptom most often reported in human cases.
The three veterinarians also reported to the investigators that they had not worked with cattle or poultry known to be infected with the virus. In one case, a veterinarian said he had practiced only in Georgia (on dairy cows) and South Carolina (on poultry) – two states that have not reported H5N1 infections in dairy cows.
Seema Lakdawala, microbiologist at Emory University in Atlanta – who was not involved in research – said that it was surprised that only 2% of veterinarians interviewed positive for antibodies, considering Another CDC study has shown that 17% of sampled dairy people had been infected. But she said that she was even more surprised than none of them knows that they had been infected or that they had worked with infected animals.
“These surprising results indicate that serum surveillance studies are important to shed light on the risk of infections that are not diagnosed,” she said. “Veterinarians are on the front line of the epidemic, and an increase in biosecurity practices such as respiratory and eye protection should reduce their risk of exposure.”
Jennifer Nuzzo, director of the Pandemic Center at Brown University, described the study as a “good and bad news”.
“On the one hand, we see concerning the evidence that there may be more epidemics H5N1 on farms than what is reported,” she said. “On the other hand, I am reassured that there is no evidence that the infections between the veterinarians have been widespread.
The analysis was carried out in September 2024. At that time, there were only four human cases reported, and the infection would have been limited to dairy cattle in 14 states. Since then, 68 people have been infected – 40 working with infected dairy cows – and the virus has been reported, the herds have infected in 16 states.
John Korslund, a retired scientist from the American Department of Agriculture, said in an email that finding H5N1 antibodies in the veterinarians' blood was an interesting means “but very imprecise to measure the impact of the cattle of the state”. But he stressed that “that humans are sensitive to subclinical infections and the risk of possible restocking, which we already knew, I suppose.”
The restocking occurs when a person or an animal is infected with more than one influenza virus, allowing the two to mingle and exchange “material”, potentially creating a new, more virulent strain.
Most importantly, he said, version D1.1 of the strain-which was detected in Dairy cattle of Nevada And a person living in the state – is “to change the landscape. … (P) Eople can be more sensitive (or not) with greater severity potential (or not). “
“I am convinced that we will find him in other states. His behavior and transmissibility inside and between cattle herds are still roughly a black box,” he said.
