Human bird flu cases tick up; second Colorado poultry farm reports spread
A second Colorado poultry farm has reported a case of bird flu in a worker, marking the state's seventh human case this month amid the ongoing outbreak among dairy cows.
Colorado health officials said the seventh case is, for now, a presumptive positive. That means that the person has tested positive at the state level while confirmatory testing is being carried out at the Centers for Disease Control and Prevention.
The presumptive positive worker was at a poultry facility in the state's northeastern Weld County. In recent weeks, six workers at another poultry farm in Weld also tested positive for bird flu. In that facility, a commercial egg layer operation with about 1.8 million birds, workers were infected as they culled chickens known to be infected with the highly pathogenic avian influenza. Genetic testing of the virus in the birds and the workers indicated that they were infected with a strain of H5N1 closely related to the virus found spreading in dairy cattle and to dairy farm workers.
The US Department of Agriculture confirmed in late March that the H5N1 bird flu that had been spreading globally among wild birds for years had unexpectedly jumped to dairy cows in the US. To date, at least 168 herds in 13 states have tested positive for the virus. Amid the dairy outbreak, 11 humans have contracted the virus. Four of the cases were among dairy workers: one in Texas, two in Michigan, and one in Colorado, which was reported earlier this month. The remaining seven cases were among poultry workers, all in Colorado. (There was also a human H5N1 case in a Colorado poultry worker in 2022, prior to the virus jumping to cows.)
