"Though H5N1 avian flu outbreaks on US dairy farms have declined sharply over the past several months, scientists are still sorting out how the virus spreads on farms, and new findings from California outbreak hot spots suggest that airborne spread and contaminated wastewater may play roles. Researchers from Emory University and their colleagues from California, Colorado, Michigan, and Virginia recently published their findings from experiments on 14 dairy farms from two California regions in bioRxiv, a preprint server."