Avian influenza viruses can persist in footbaths and manure.

Avian influenza viruses can persist in footbaths and manure.Growers shouldn’t assume the disinfectants they use in footbaths are effective against avian influenza (AI), indicates a study from the University of California–Davis. Researchers conducted a survey about biosecurity practices in California and then used the information to design experiments to test the effectiveness of footbath disinfectants against AI. They also evaluated the longevity of AI viruses under different conditions. “Surprisingly,” they say, quaternary ammonia and quaternary ammonia plus glutaraldehyde-based footbaths did not eliminate highly pathogenic H5N8 or low-pathogenic H6N2 particles on boots. However, a chlorine-based granulated disinfectant was able to destroy the virus, say Rüdiger Hauck* and colleagues. To evaluate the longevity of AI viruses in litter and feces, they seeded different bedding samples from commercial layer, broiler and turkey production units with the same two AI viruses. Live H5N8 particles in layer feces remained for at least 96 hours, compared to less than 60 hours in broiler and turkey bedding. However, H6N2 low-pathogenic viruses persisted less than 24 hours in all the different substrates. This knowledge may help producers determine effective litter treatments to destroy AI viruses in the bedding material.