Abstract:
Human enteric viruses are important agents of waterborne illness. They are typically distributed in environmental waters in low numbers, which necessitates concentration of tens to hundreds of liters for effective detection. A variety of charged filters have been described, but the Virosorb 1 MDS filter is the most commonly used filter for fresh water and the OptiCap XL filter used for seawater. This study evaluates the effectiveness of the a recently developed positively-charged filter, the ViroCap capsule filter, for concentration of coliphage MS2, poliovirus type 1 (PV1), and adenovirus type 2 (Ad2) from deionized water and simulated seawater. Mean adsorption for MS2 by the ViroCap was 88%. Overall recoveries of PV1 using the ViroCap filters were similar to those of 1MDS filters, while recovery of MS2 using ViroCap filter was significantly higher (p=0.01) than those of 1 MDS filters. Recovery of both viruses from simulated seawater was not statistically different than recovery from deionized water (p=0.36 and 0.81 for MS2 and PV1, respectively), demonstrating that the ViroCap is capable of recovering viruses from ionic matrices, thus overcoming a substantial limitation of other positively charged filters. Furthermore, the ViroCap filter showed greater recovery of MS2 and PV1 than the OptiCap filter, the generally accepted filter for ionic matrices. Second order probabilistic modeling was performed on the generated data set to assess the impact of presenting data through standard summary statistics. Nested loops of uncertainty and variability were generated and Monte-Carlo sampling utilized to determine the range of recoveries inherent in the data set. Understanding of the magnitude of the variability that can arise from a single experimental set-up is necessary when using recovery estimates to determine environmental contamination.