You are here:
Identifying septic pollution exposure routes during a waterborne norovirus outbreak - A new application for human-associated microbial source tracking qPCR
Citation:
Mattioli, M., K. Benedict, J. Murphy, A. Kahler, K. Kline, A. Longenberger, P. Mitchell, S. Watkins, P. Berger, O. Shanks, C. Barrett, L. Barclay, A. Hall, V. Hill, AND A. Weltman. Identifying septic pollution exposure routes during a waterborne norovirus outbreak - A new application for human-associated microbial source tracking qPCR. JOURNAL OF MICROBIOLOGICAL METHODS. Elsevier Science Ltd, New York, NY, 180:106091, (2021). https://doi.org/10.1016/j.mimet.2020.106091
Impact/Purpose:
Fecal pollution is the number one biological contaminant in U.S. surface waters with polluted sites in every state. When present, fecal waste can pose a serious public health risk and can lead to severe economic burdens, especially in communities that rely on clean and safe water. Fecal pollution can originate from untreated sewage due to combined sewer overflows, spills, and leaky infrastructure. In response to this nationwide need, the U.S. EPA ORD maintains an active research program to develop, validate, implement, and provide technical support for tools to characterize fecal pollution sources in environmental settings. Information covered in this manuscript was prepared based on priority research needs in the EPA Research Action Plan (SSWR Research Area 3, Output #8, Product 1).
Description:
In June 2017, the Pennsylvania Department of Health (PADOH) was notified of multiple norovirus outbreaks associated with 179 ill individuals who attended separate events held at an outdoor venue and campground over a month period. Epidemiologic investigations were unable to identify a single exposure route and therefore unable to determine whether there was a persistent contamination source to target for exposure mitigation. Norovirus was detected in a fresh recreational water designated swimming area and a drinking water well. A hydrogeological site evaluation suggested a nearby septic leach field as a potential contamination source via ground water infiltration. Geological characterization revealed a steep dip of the bedrock beneath the septic leach field toward the well, providing a viral transport pathway in a geologic medium not previously documented as high risk for viral ground water contamination. The human-associated microbial source tracking (MST) genetic marker, HF183, was used as a microbial tracer to demonstrate the hydrogeological connection between the malfunctioning septic system, drinking water well, and recreational water area. Based on environmental investigation findings, venue management and local public health officials implemented a series of outbreak prevention strategies including discontinuing the use of the contaminated well, issuing a permit for a new drinking water well, increasing portable toilet and handwashing station availability, and promoting proper hand hygiene. Despite the outbreaks at the venue and evidence of ground water contamination impacting nearby recreational water and the drinking water well, no new norovirus cases were reported during a large event one week after implementing prevention practices. This investigation highlights a new application for human-associated MST methods to trace hydrological connections between multiple fecal pollutant exposure routes in an outbreak scenario. In turn, pollutant source information can be used to develop effective intervention practices to mitigate exposure and prevent future outbreaks associated with human fecal contaminated waters.
URLs/Downloads:
DOI: Identifying septic pollution exposure routes during a waterborne norovirus outbreak - A new application for human-associated microbial source tracking qPCR