ASSESSING THE EFFECTS OF ANAEROBIC DIGESTION ON AVIAN INFLUENZA VIRUS (H5N2).

It has been suggested that ingestion of contaminated water during swimming and/or direct intranasal or conjunctival exposure to water are potential modes of H5N1 avian influenza virus (AIV) transmission. Should H5N1 AIV become adapted to humans, domestic wastewater treatment systems could become contaminated with the virus, which might exacerbate the spread of this disease and put plant operators at risk. The objectives of the work reported herein were to determine if the H5N2 AIV (as a surrogate for H5N1) is inactivated by routine anaerobic digestion of wastewater sludges. Greater than two log inactivation of H5N2 was achieved by anaerobic digestion under typical wastewater treatment conditions. Infectious H5N2 concentrations dropped from an initial 103.6 Embryo Infective Doses/mL (EID/mL) to undetectable levels in all three anaerobic digester replicates after 72 hours. After two weeks, the virus in the PBS control at 37°C had also dropped to below detectable levels, while that in the PBS control at 4°C remained detectable throughout the entire three week trial, although at low levels (