Recent Cattle Outbreak Might Have Spread to Humans!

A recent study explains the cattle outbreak, which shows a strong connection to humans, it may spread to humans. A worker in a dairy farm in Texas caught the infection leading to pink eye but he got better. This is the first ever case where highly pathogenic bird flu that is HPAI A(H5N1) virus has spread from animal to humans, 

The H5N1 virus spread across and among herds shows that cows can easily pass it to each other. Moving animals around is the biggest transmission source. This virus can easily jump from dairy farms to nearby chicken coops too. A few things might help the virus spread between farms: workers going from one farm to another; dirty trucks and tools used at different places; and lots of people coming and going from the farms.

Right now, there is no genetic or disease-tracking proof that wild birds are passing H5N1 to cows, but we can’t say for sure that it’s not happening.

The USDA has asked vets and farmers to keep good biosecurity; watch for, isolate, and check sick animals; limit cattle movements; and quarantine and observe any new dairy cattle for 30 days when they arrive. Also, since April 29, a federal order requires testing of milk-producing dairy cattle for HPAI before they move between states, and telling the USDA’s Animal and Plant Health Inspection Service (APHIS) about positive nucleic acid detection and serology results for livestock.

Scientists found no signs in the patient’s sample that it might resist current flu drugs. The outbreak in dairy cows has surprised scientists. Cattle may have encountered HPAI H5 subtype viruses for many years, says Martin Beer DVM, who runs the Institute of Diagnostic Virology at the Friedrich-Loeffler-Institut, Germany’s Federal Research Institute for Animal Health.

A new study found that cow mammary glands have duck and human influenza A virus receptors. This could explain the high H5N1 virus levels in infected cow’s milk. It also suggests that “cattle have the potential to act as a mixing vessel” for new influenza A viruses, according to the authors in their preprint article, which hasn’t gone through peer review yet.

Right now, US and global health officials say the risk to the public remains low. However, they emphasise the need to watch the situation and be ready. “This ongoing increase in mammal species, plus being closer to our food source means we need to take action,” said Nahid Bhadelia MD MALD, who leads the Boston University Center on Emerging Infectious Diseases.

Reference:

Avian influenza virus type A (H5N1) in U.S. dairy cattle | American Veterinary Medical Association [Internet]. Animal Health  

Abbasi J. Bird Flu Outbreak in Dairy Cows Is Widespread, Raising Public Health Concerns ‌doi:10.1001/jama.2024.8886