Loading...
Two risk assessments: Evaluating the use of indicator HF183 Bacteroides versus pathogen measurements for modelling recreational illness risks in an urban watershed
Skiendzielewski, K. Burch, T. Stokdyk, J. McGinnis, Shannon McLoughlin, Shane Firnstahl, A. Spencer, S. Borchardt, M. Murphy, Heather M.
Skiendzielewski, K.
Burch, T.
Stokdyk, J.
McGinnis, Shannon
McLoughlin, Shane
Firnstahl, A.
Spencer, S.
Borchardt, M.
Murphy, Heather M.
Citations
Altmetric:
Genre
Journal article
Date
2024-05-29
Advisor
Committee member
Department
Epidemiology and Biostatistics
Permanent link to this record
Collections
Research Projects
Organizational Units
Journal Issue
DOI
https://doi.org/10.1016/j.watres.2024.121852
Abstract
The purpose of this study was to evaluate the performance of HF183 Bacteroides for estimating pathogen exposures during recreational water activities. We compared the use of Bacteroides-based exposure assessment to exposure assessment that relied on pathogen measurements. We considered two types of recreational water sites: those impacted by combined sewer overflows (CSOs) and those not impacted by CSOs. Samples from CSOimpacted and non-CSO-impacted urban creeks were analysed by quantitative polymerase chain reaction
(qPCR) for HF183 Bacteroides and eight human gastrointestinal pathogens. Exposure assessment was conducted two ways for each type of site (CSO-impacted vs. non-CSO impacted): 1) by estimating pathogen concentrations from HF183 Bacteroides concentrations using published ratios of HF183 to pathogens in sewage and 2) by estimating pathogen concentrations from qPCR measurements. QMRA (quantitative microbial risk assessment) was then conducted for swimming, wading, and fishing exposures. Overall, mean risk estimates varied from 0.27 to 53 illnesses per 1,000 recreators depending on exposure assessment, site, activity, and norovirus dose-response model. HF183-based exposure assessment identified CSO-impacted sites as higher risk, and the recommended HF183 risk-based threshold of 525 genomic copies per 100 mL was generally protective of public health at the CSO-impacted sites but was not as protective at the non-CSO-impacted sites. In the context of our urban watershed, HF183-based exposure assessment over- and under-estimated risk relative to exposure assessment
based on pathogen measurements, and the etiology of predicted pathogen-specific illnesses differed significantly. Across all sites, the HF183 model overestimated risk for norovirus, adenovirus, and Campylobacter jejuni, and it underestimated risk for E. coli and Cryptosporidium. To our knowledge, this study is the first to directly compare health risk estimates using HF183 and empirical pathogen measurements from the same waterways. Our work highlights the importance of site-specific hazard identification and exposure assessment to decide whether HF183 is applicable for monitoring risk.
Description
Citation
K. Skiendzielewski, T. Burch, J. Stokdyk, S. McGinnis, S. McLoughlin, A. Firnstahl, S. Spencer, M. Borchardt, H.M. Murphy, Two risk assessments: Evaluating the use of indicator HF183 Bacteroides versus pathogen measurements for modelling recreational illness risks in an urban watershed, Water Research, Volume 259, 2024, 121852, ISSN 0043-1354, https://doi.org/10.1016/j.watres.2024.121852. (https://www.sciencedirect.com/science/article/pii/S004313542400753X)
Citation to related work
Elsevier
Has part
Water Research, Vol. 259
ADA compliance
Embedded videos
License
Attribution CC BY