Genetic sequences of the H5N1 bird flu released by USDA

TThe U.S. Department of Agriculture, which has been under pressure from scientists at home and abroad to share more data on H5N1 bird flu outbreaks in dairy cows, uploaded a large number of genetic sequences of the pathogen late Sunday.

Access to the 239 genetic sequences will help scientists assess whether the dangerous virus has acquired mutations that allow it to spread more easily to and among mammals, and whether additional changes have been observed as it moves from cow to cow and from herd to herd. In addition to virus sequences from livestock, the hoard also includes sequences of viruses from cats, chickens, a skunk, a raccoon, a grackle, a blackbird and a goose, the agency said.

Rick Bright, a pandemic planning consultant who has been outspokenly critical of the USDA for being slow to share sequencing data, noted that the revelation was “a long time coming.”

“But I am grateful,” he said of the government’s move. “And curious to see what we can discover.”

“I just hope the data keeps coming,” said Bright, former director of the Biomedical Advanced Research and Development Authority (BARDA) and former head of the Rockefeller Foundation’s now-defunct Pandemic Prevention Institute.

Michael Worobey, an evolutionary biologist at the University of Arizona, said what is currently posted is raw data, which is very useful but will take some time to analyze. “At least now, servers all over the world [run by] groups working on this can rev their engines,” he told STAT.

Worobey said it was not immediately clear whether the sequences came from samples collected at different times during the outbreak, which has been going on for weeks.

The USDA announced March 25 that it had confirmed H5N1 in dairy cows in Texas, a finding that has upset scientists who have been tracking the progress of this virus around the world and in species after species of mammals. Until now, cows have not been among the animals found to be infected with the virus.

The department initially shared a number of sequences, all of which appeared to be from the original outbreak in Texas. Since then, 32 herds in eight states have been confirmed infected with H5N1. Although the disease is fatal to poultry and some species of mammals, the disease does not appear to cause serious illness in cows. But milk production in infected cows decreases and the milk produced is thick, colorless and riddled with H5N1 viruses. Farmers have been told to destroy milk from infected cows.

Although the USDA believes the virus spreads from cow to cow, it is not yet certain how it is transmitted. There do not appear to be large amounts of virus in the nasal passages of infected animals. It is suggested that transmission may occur through the milking process, perhaps through the successive use of milking equipment or through the movement of people between farms.