Human polyomavirus: Advantages and limitations as a human-specific viral marker in aquatic environments.

Human polyomaviruses (HPyVs) cause persistent infections in organs such as kidney, brain, skin, liver, respiratory tract, etc., and some types of HPyV are constantly excreted in the urine and/or feces of infected and healthy individuals. The use of an enteric virus as an indicator for human sewage/waste contamination in aquatic environments has been proposed; HPyVs are a good candidate since they are routinely found in environmental water samples from different geographical areas with relatively high abundance. HPyVs are highly human specific, having been detected in human waste from all age ranges and undetected in animal waste samples. In addition, HPyVs show a certain degree of resistance to high temperature, chlorine, UV, and low pH, with molecular signals (i.e., DNA) persisting in water for several months. Recently, various concentration methods (electronegative/positive filtration, ultrafiltration, skim-milk flocculation) and detection methods (immunofluorescence assay, cell culture, polymerase chain reaction (PCR), integrated cell culture PCR (ICC-PCR), and quantitative PCR) have been developed and demonstrated for HPyV, which has enabled the identification and quantification of HPyV in various environmental samples, such as sewage, surface water, seawater, drinking water, and shellfish. In this paper, we summarize these recent advancements in detection methods and the accumulation of environmental surveillance and laboratory-scale experiment data, and discuss the potential advantages as well as limitations of HPyV as a human-specific viral marker in aquatic environments.