Colorado state authorities are still awaiting results from many of at least 68 workers who have shown symptoms of infection by highly-pathogenic avian influenza.
There are more than 150 workers at the layer chicken operation.
Officials said workers may have shucked their protective masks as the temperature in the area topped 37.
The Colorado Department of Public Health and Environment has this distributed post-exposure antiviral medicine as a precaution to more than 150 workers at a poultry farm hit by avian flu.
Five of those workers from the commercial egg layer operation on a farm in Weld County have been found to be presumptively positive by results from CDPHE’s State Public Health Laboratory, with four already confirmed by the U.S. Centers for Disease Control and Prevention (CDC).
The five workers were part of a catching crew.