Integrating Microbial Source Tracking with Quantitative Microbial Risk Assessment to Evaluate Site Specific Risk Based Thresholds at Two South Florida Beaches

Details

• Personal Author:
  Bonacolta A ; Ferguson A ; Gidley M ; Gitter A ; Mena KD ; Sinigalliano C ; Solo-Gabriele H
• Description:
  Quantitative microbial risk assessment (QMRA) can be used to evaluate health risks associated with recreational beach use. This study developed a site-specific risk assessment using a novel approach that combined quantitative PCR-based measurement of microbial source tracking (MST) genetic markers (human, dog, and gull fecal bacteria) with a QMRA analysis of potential pathogen risk. Water samples (n = 24) from two recreational beaches were collected and analyzed for MST markers as part of a broader Beach Exposure And Child Health Study that examined child behavior interactions with the beach environment. We report here the measurements of fecal bacteria MST markers in the environmental DNA extracts of those samples and a QMRA analysis of potential health risks utilizing the results from the MST measurements in the water samples. Human-specific Bacteroides was enumerated by the HF183 Taqman qPCR assay, gull-specific Catellicoccus was enumerated by the Gull2 qPCR assay, and dog-specific Bacteroides was enumerated by the DogBact qPCR assay. Derived reference pathogen doses, calculated from the MST marker concentrations detected in recreational waters, were used to estimate the risk of gastrointestinal illness for both children and adults. Dose-response equations were used to estimate the probability of the risk of infection (Pinf) per a swimming exposure event. Based on the QMRA simulations presented in this study, the GI risk from swimming or playing in water containing a mixture of human and non-human fecal sources appear to be primarily driven by the human fecal source. However, the estimated median GI health risk for both beaches never exceeded the U.S. EPA risk threshold of 32 illnesses per 1,000 recreation events. Our research suggests that utilizing QMRA together with MST can further extend our understanding of potential recreational bather risk by identifying the source contributing the greatest risk in a particular location, therefore informing beach management responses and decision-making. [Description provided by NIOSH]
• Subjects:
  Communicable Diseases Microbiology Occupational Health Safety
• Keywords:
  Author Keywords: Fecal Indicator Bacteria Bacterial Disease Beach Child Children Exposure Infectious Diseases Microbial Source Tracking Pathogens Quantitative Microbial Risk Assessment Risk Assessment

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• ISSN:
  1664-302X
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Florida ; North Carolina ; OSHA Region 4 ; OSHA Region 6 ; Texas
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  14
• NIOSHTIC Number:
  nn:20069749
• Citation:
  Front Microbiol 2023 Oct; 14:1210192
• Contact Point Address:
  Anna Gitter, Department of Epidemiology, Human Genetics and Environmental Sciences, University of Texas Health Science Center Houston School of Public Health, El Paso, TX, United States
• Email:
  anna.gitter@uth.tmc.edu
• Federal Fiscal Year:
  2024
• Performing Organization:
  University of Texas Health Science Center, Houston
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Frontiers in Microbiology
• End Date:
  20250630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:3930d5cd15a313393d4f8223553ef2c7b6dbd6f5d2775254f09a52121c9195d3231c028e7222670b693e421b29dff73df93955395c1b2f57d129b0e87bf82cee
• Download URL:
  https://stacks.cdc.gov/view/cdc/208111/cdc_208111_DS1.pdf
• File Type:
  [PDF - 2.19 MB ]