Behaviour and recovery of human adenovirus from tropical sediment under simulated conditions.

This study assessed the contributions of pH and organic matter (OM) on the recovery of infectious human adenovirus 5 (HAdV-5) and genome copies (GCs) in waters that were artificially contaminated with tropical soil. The use of a mathematical equation was proposed based on the flocculation index of clay to assess the recovery of total GCs in these controlled assays. The results suggest that solids in the water reduced the viral genome copy loads per millilitre (GC · mL(-1)) and viral infectivity. OM did not influence the GC · mL(-1) recovery rate (p > 0.05) but led to a 99% (2 log10) reduction in plaque-forming unit counts per millilitre (PFU/mL), which indicates that infectivity and gene integrity were non-related parameters. Our findings also suggest that acidic pH levels hinder viral inactivation and that clay is the main factor responsible for the interactions of HAdV-5 with soil. These findings may be useful for future eco-epidemiological investigations and studies of viral inactivation or even as parameters for future research into water quality analysis and water treatment.