On August 13^th, the Food and Drug Administration announced results of a second round of assays of pasteurized dairy products for H5N1 virus.  Samples were collected by a third-party from retail outlets during June and July and were processed at a USDA-ARS laboratory. 

No viable virus was detected in any of 167 samples of fluid milk or products made from pasteurized milk including cheeses, butter and ice cream.  The survey, confirmed previous laboratory studies that pasteurization was adequate to destroy H5N1 strain B3.13, mammalian adapted avian influenza virus. 

To date, 190 herds have been diagnosed with bovine influenza-H5N1 since April in 13 states.  Of this total, it is significant that 63 were herds in Colorado.  This indicates the effectiveness of a state mandatory bulk milk-sampling program introduced by the Colorado state Veterinarian.  Positive flocks are quarantined for the duration of the infection, preventing spread to other dairy farms and indirectly to egg production flocks. “spill-over” from dairy herds to egg-production farms has been documented or presumed in outbreaks in Michigan and Colorado by the movement of infected or contaminated personnel or fomites.