Composting for avian influenza virus elimination

Abstract

Effective sanitization is important in viral epizootic outbreaks to avoid further spread of the pathogen. This study examined thermal inactivation as a sanitizing treatment for manure inoculated with highly pathogenic avian influenza virus H7N1 and bacteriophages MS2 and 6. Rapid inactivation of highly pathogenic avian influenza virus H7N1 was achieved at both mesophilic (35°C) and thermophilic (45 and 55°C) temperatures. Similar inactivation rates were observed for bacteriophage 6, while bacteriophage MS2 proved too thermoresistant to be considered a valuable indicator organism for avian influenza virus during thermal treatments. Guidelines for treatment of litter in the event of emergency composting can be formulated based on the inactivation rates obtained in the study.

Fig 1

Changes in temperature (°C) and survival (log₁₀ TCID₅₀/PFU g⁻¹ compost) of H7N1 HPAIV (a, b), ϕ6 phage (c, d), and MS2 phage (e, f) during composting in laboratory-scale compost reactor 1 (■, solid line), reactor 2 (●, dashed line), mixture 1 (left), and mixture 2 (right). Gray markers (square, circle) represent samplings where the number of viruses was found to be below the detection limit.