A study by the US Department of Agriculture has found that properly cooked hamburger patties cannot contain the H5N1 avian influenza virus. The study involved injecting an inactivated H5N1 mimic into ground beef patties and cooking them at specific temperatures. The USDA also tested 30 samples of ground beef from retail stores and did not detect the virus. However, the FDA found H5N1 particles in about 20% of dairy product samples, but no viable virus was present. The CDC is now monitoring wastewater for the influenza A virus, with high levels detected in Illinois and Florida, despite the lack of detection in cows in these states. The CDC is also urging states to provide protective equipment to slaughterhouse and dairy workers.