Comparison of methods for concentrating human adenoviruses, polyomavirus JC and noroviruses in source waters and drinking water using quantitative PCR.

Human adenovirus and JC polyomavirus have been proposed as viral indicators of human faecal contamination of water. This study compared concentration and nucleic acid extraction methods and defines a protocol for quantifying human adenoviruses (HAdV), JC polyomavirus (JCPyV) and noroviruses (NoV) in source and drinking water. River water samples and spiked tap water samples were used to evaluate virus recovery, applying quantitative PCR (qPCR) to five concentration methods. In the case of 10-L samples, the use of ultrafiltration cartridges produced acceptable recoveries for HAdV and JCPyV, but they were inefficient for noroviruses and could not be applied to high-volume and river water samples with medium turbidity. The glass wool method with pre-acidification gave similar recoveries and made it possible to detect NoV. In the case of 50-L samples, the method that produced the highest recovery efficiency and applicability was glass wool filtration. Comparing different sample volumes of a river used as source water showed that the largest number of viruses were quantified when lower volumes (1L) were tested (1.5 x 10(4) HAdV genome copies (GC)/L and 2.8 x 10(3) JCPyV GC/L). The methods developed are easy to standardize and may be valuable tools for the control of viral contamination in source water and for assessing the efficiency of virus removal in drinking water treatment plants.