Survival of Human Adenovirus 41 in Land-Applied Manure and Biosolids

Abstract

Human Adenovirus 41 (Ad41) is an important human enteric pathogen and widely prevalent in the environment. The aim of this study was to assess the survival of Ad41 based on genome stability and infectivity in different types of manure and three types of biosolids. For viral survival studies, Ad41 was added to pelletized poultry litter (PL), alum-treated poultry litter (AL), raw poultry litter (RPL), liquid dairy manure (DM), swine manure (SM), and three types of biosolids 1, 2, 3. All samples were stored at 20 or 4°C and analyzed every 10 days for up to 60 days. Quantification PCR (qPCR) standard curves were generated for PL, AL, biosolids 1, and DM to measure the number of viral genomic copies remaining in the samples. To study the infectivity, all contaminated manure/biosolids samples were added to mammalian cell culture and viral mRNA was detected using one-step RT–PCR. Overall, Ad41 viral genomes were stable at both 20 and 4°C and there was no significant loss of viral DNA after 60 days in PL, AL, biosolids type 1, and DM. However, infectivity was lost almost immediately in high pH biosolids type 2 and 3, and infectivity decreased quickly in DM, with estimated T90 of 4.3 and 8.7 days at 20 and 4°C, respectively. Ad41 had ~1.9 log loss of infectivity after added in SM and biosolids type 1 at day 0, and estimated T90 was 12.5 and 28.6 days for biosolids type 1, and 19.1 and 51.0 days for SM at 20 and 4°C, respectively. Ad41 maintained infectivity in all three poultry litter, and after 60 days incubation, there were significantly more infectious virus in PL, AL, and RPL than biosolids 1, SM, and DM at 20°C.