title: Decontamination of a drinking water pipeline system contaminated with adenovirus and Escherichia coli utilizing peracetic acid and chlorine.
abstract: A contaminated drinking water distribution network can be responsible for major outbreaks of infections. In this study, two chemical decontaminants, peracetic acid (PAA) and chlorine, were used to test how a laboratory-scale pipeline system can be cleaned after simultaneous contamination with human adenovirus 40 (AdV40) and Escherichia coli. In addition, the effect of the decontaminants on biofilms was followed as heterotrophic plate counts (HPC) and total cell counts (TCC). Real-time quantitative polymerase chain reaction (qPCR) was used to determine AdV40 and plate counting was used to enumerate E. coli. PAA and chlorine proved to be effective decontaminants since they decreased the levels of AdV40 and E. coli to below method detection limits in both water and biofilms. However, without decontamination, AdV40 remained present in the pipelines for up to 4 days. In contrast, the concentration of cultivable E. coli decreased rapidly in the control pipelines, implying that E. coli may be an inadequate indicator for the presence of viral pathogens. Biofilms responded to the decontaminants by decreased HPCs while TCC remained stable. This indicates that the mechanism of pipeline decontamination by chlorine and PAA is inactivation rather than physical removal of microbes.
authors.affiliation: Department of Environmental Health, Water and Health Unit, National Institute for Health and Welfare, P.O. Box 95, FI-70701 Kuopio, Finland. ari.kauppinen@thl.fi
authors.forename: Ari
authors.initials: A
authors.lastname: Kauppinen
authors.forename: Jenni
authors.initials: J
authors.lastname: Ikonen
authors.forename: Anna
authors.initials: A
authors.lastname: Pursiainen
authors.forename: Tarja
authors.initials: T
authors.lastname: Pitkänen
authors.forename: Ilkka T
authors.initials: IT
authors.lastname: Miettinen
mesh_terms: D000256:Adenoviridae / Q000187:drug effects*; D018441:Biofilms; D002713:Chlorine / Q000494:pharmacology*; D004202:Disinfectants / Q000494:pharmacology; D060766:Drinking Water; D004926:Escherichia coli / Q000187:drug effects*; D010463:Peracetic Acid / Q000494:pharmacology*; D013997:Time Factors; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods
chemical_list: D004202:Disinfectants; D060766:Drinking Water; D002713:Chlorine; D010463:Peracetic Acid