Extended water stagnation in buildings during the COVID-19 pandemic increases the risks posed by opportunistic pathogens.

Autor: Huang CK; Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, QLD 4072, Australia.; Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, QLD 4102, Australia., Weerasekara A; Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, QLD 4072, Australia.; Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, QLD 4102, Australia., Lu J; Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, QLD 4072, Australia., Carter R; Respiratory Research Unit, Gallipoli Medical Research Institute, QLD 4120, Australia., Weynberg KD; Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia., Thomson R; Respiratory Research Unit, Gallipoli Medical Research Institute, QLD 4120, Australia.; Greenslopes Clinical Unit, The University of Queensland, QLD Australia., Bell S; Adult Cystic Fibrosis Centre, The Prince Charles Hospital, Australia.; Child Health Research Centre, Faculty of Medicine, The University of Queensland, QLD Australia.; Translational Research Institute, Australia., Guo J; Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, QLD 4072, Australia.
Jazyk: angličtina
Zdroj: Water research X [Water Res X] 2023 Sep 09; Vol. 21, pp. 100201. Date of Electronic Publication: 2023 Sep 09 (Print Publication: 2023).
DOI: 10.1016/j.wroa.2023.100201
Abstrakt: The regrowth and subsequent exposure of opportunistic pathogens (OPs) whilst reopening buildings that have been locked down due to the stay-at-home restrictions to limit the spread of COVID-19, is a public health concern. To better understand such microbiological risks due to lowered occupancy and water demand in buildings, first and post-flush water samples (n = 48) were sampled from 24 drinking water outlets from eight university buildings in two campuses (urban and rural), with various end-user occupancies. Both campuses were served with chlorinated water originating from a single drinking water distribution system in South-East Queensland, situated 14 km apart, where the rural campus had lower chlorine residuals. Culture-dependent and culture-independent methods (such as flow cytometry, qPCR and 16S rRNA gene amplicon sequencing) were used concurrently to comprehensively characterise the OPs of interest ( Legionella spp., Pseudomonas aeruginosa , and nontuberculous mycobacteria (NTM)) and the premise plumbing microbiome. Results showed that buildings with extended levels of stagnation had higher and diverse levels of microbial growth, as observed in taxonomic structure and composition of the microbial communities. NTM were ubiquitous in all the outlets sampled, regardless of campus or end-user occupancy of the buildings. qPCR and culture demonstrated prevalent and higher concentrations of NTM in buildings (averaging 3.25 log 10 [estimated genomic copies/mL]) with extended stagnation in the urban campus. Furthermore, flushing the outlets for 30 minutes restored residual and total chlorine, and subsequently decreased the levels of Legionella by a reduction of 1 log. However, this approach was insufficient to restore total and residual chlorine levels for the outlets in the rural campus, where both Legionella and NTM levels detected by qPCR remained unchanged, regardless of building occupancy. Our findings highlight that regular monitoring of operational parameters such as residual chlorine levels, and the implementation of water risk management plans are important for non-healthcare public buildings, as the levels of OPs in these environments are typically not assessed.
Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(© 2023 The Authors. Published by Elsevier Ltd.)
Databáze: MEDLINE
Externí odkaz: