Efficacy of composting dead poultry and farms wastes infected with avian influenza virus H5N1.

摘要

Composting had proven to be an environmentally sound method for disposing dead birds. The composting process management and monitoring it's thermal profile, moisture content, nutrient ingredients were determined and recorded during day 1 to 33. Isolation and characterization of H5N1 avian influenza virus (AIV) in freshly dead birds and their wastes before, during and after composting was carried out using RT-PCR based assay and sequence analysis. In composting the temperature was increased gradually from 40-60 degrees C through days 5 to 15 then declined after day 15 till end composting. The dry conditions and increased temperature were important virus determinants. Failure of re-isolation of virus in consequence to increased temperature during composting was proven when tested at day 15, end composting and dryness period. AIV was characterized before composting in the birds trachea and compost mix. Positive isolation, characterization and sequence analysis of fragment 4 of H5 gene revealed clustering of the virus with those field strains circulating among chicken population in Egypt in 2011. Testing the composting mix at the day 15 and end of composting by RT-PCR assay revealed negative amplification confirming the efficacy of composting process for destroying AIV. Composting within the newly designed closed composter achieved unfavorable thermal and dryness conditions for H5N1 surviving with no isolation and characterization of AIV H5N1 from field dead birds and their wastes. The study proposes composting as a reliable, environmentally safe way to dispose poultry waste infected with H5N1 AIV.