The U.S. Division of Agriculture introduced Wednesday that 4 dairy herds in Nevada lately decided to be contaminated with H5N1 chicken flu had been in reality contaminated with a distinct pressure of the virus than has been circulating in cows for the previous 12 months.
The invention, consultants mentioned, make it clear driving this virus out of cows shall be tougher than the USDA has estimated.
The model within the Nevada herds is one which has been circulating in wild birds. Additionally it is the model behind the extreme an infection of a teenager in British Columbia, Canada, final 12 months, and a deadly an infection in Louisiana final month.
Because the starting of the H5N1 outbreak in dairy cows, the USDA has insisted that each one the infections — 957 herds in 16 states up to now — hint again to a single introduction of the virus into cows in late 2023 or early 2024, probably in Texas. Break the chain of transmission, the company argued, and the outbreak would finish.
This new discovering, on account of a nationwide milk testing technique the USDA instituted in late 2024, exhibits that what occurred as soon as has occurred once more — which makes prospects for containment seem dim, given how a lot H5N1 virus is circulating at current in wild birds in a number of components of the nation.
“I’m not stunned that we’re seeing extra introductions, notably given the very widespread nature proper now of H5N1 in migratory waterfowl all through North America,” Michael Osterholm, director of the College of Minnesota’s Heart for Infectious Illness Analysis and Coverage, informed STAT. “From a containment standpoint, it simply factors out that this isn’t going to burn itself out.”
The model of the virus that has been circulating in cows has been clade 2.3.4.4b genotype B3.13. The model discovered within the Nevada cows was genotype D1.1.
The USDA mentioned in a press release posted to its web site that the discovering has not made the division rethink its strategy.
“The detection doesn’t change USDA’s [H5N1] eradication technique and is a testomony to the energy of our Nationwide Milk Testing Technique,” it mentioned.
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