A new variant of the bird flu has emerged, infecting dairy cows in Nevada, raising concerns about the potential for more severe human illness.
The same version of the bird flu that has caused serious human illnesses in North America has now turned up in dairy cows. Cattle in Nevada tested positive for the H5N1 viral variant ‘D1.1’ , which has been circulating in poultry and wild birds. This is the first time this version has been detected in dairy cattle.
H5N1, also known as avian influenza A virus subtype H5N1, is a highly pathogenic strain of the influenza A virus that affects birds.
According to the World Health Organization (WHO), most human cases are linked to direct contact with infected poultry or contaminated surfaces.
The virus has a high mortality rate in humans, but transmission between people is rare.
Outbreaks have occurred globally, particularly in Asia and Africa.
The WHO and other health organizations monitor the spread of H5N1 closely, and vaccination efforts aim to control bird populations.
Experts are concerned that the detection of D1.1 in cows may indicate another independent spillover event into dairy cows. ‘What we’re worried about is that it could be happening more often than we think,’ says veterinarian and environmental epidemiologist Meghan Davis of the Johns Hopkins Bloomberg School of Public Health. ‘We may need to be thinking far more seriously about improving the level of biosecurity on dairy farms.’
Viral variants, such as D1.1 and B3.13, are different versions of a virus that can behave similarly or differently. Even within a strain, mutations can set up new characteristics, such as a selective advantage for the virus in terms of transmission or antiviral resistance.
While the risk of H5N1 remains low for most people, the detection of D1.1 in cows raises concerns about the potential for more severe human illness. ‘We’re talking about a strain that we have seen in poultry, so we have had exposures in poultry workers,’ says Davis. ‘But we don’t know yet what kind of presentation we’re going to see in the cows.’
The H5N1 virus, also known as avian influenza A (H5N1), is a subtype of the influenza A virus.
It primarily affects birds but can be transmitted to humans through direct contact with infected poultry or contaminated surfaces.
According to the World Health Organization (WHO), there have been 863 reported cases of H5N1 in humans worldwide, resulting in 455 deaths since 2003.
The risk of human-to-human transmission is low, but the WHO and CDC recommend taking precautions when handling birds, wearing protective clothing, and practicing good hygiene to minimize the risk of infection.
The identification of D1.1 in cattle was through an enhanced surveillance program that has recently come online. Through the USDA’s National Milk Testing Strategy, states are testing bulk milk tanks and individual farm bulk milk to screen for the virus. To stay on top of the outbreak, experts recommend maintaining rigorous active and passive surveillance programs.
As the H5N1 bird flu continues to spread among dairy cattle, it is essential to improve biosecurity measures on farms. This includes regular testing, proper hygiene practices, and strict protocols for handling animals and their products. By taking these steps, we can reduce the risk of transmission and prevent further outbreaks.
Biosecurity measures are crucial in dairy farms to prevent disease outbreaks and maintain herd health.
Regular cleaning and disinfection of equipment, housing, and surrounding areas are essential.
Implementing strict protocols for animal movement and visitor access can also reduce the risk of disease transmission.
Vaccination programs and monitoring of animal health are also vital components of biosecurity in dairy farms.
According to the National Institute of Food and Agriculture (NIFA), implementing biosecurity measures can increase milk production by up to 10% and reduce antibiotic use by 20%.
Regular training for farm staff on biosecurity best practices is also recommended.
As the situation with H5N1 continues to evolve, it is crucial that researchers and policymakers work together to stay ahead of the outbreak. This includes ongoing surveillance, research into the virus’s behavior, and development of effective treatments and vaccines. By supporting climate journalism and staying informed about the latest developments in science, we can ensure that our response to this crisis is informed by science and guided by evidence.
- sciencenews.org | A second version of bird flu is infecting cows. What does that mean?
