By Hugo Francisco de Souza Reviewed by Lauren Hardaker May 8 2026 Infectious H5N1 virus detected in dairy farm air and wastewater, alongside evidence of hidden cattle infections, suggests an outbreak may be spreading through more routes than previously recognized.  Study: Surveillance on California dairy farms reveals multiple possible sources of H5N1 influenza virus transmission . Image credit: Parilov/Shutterstock.com In a recent study published in  PLOS Biology , researchers conducted a