The objective of the study, by Marshfield Clinic Research Foundation (MCRF) and the U.S. Geological Survey (USGS), was to determine whether the amount of Mississippi River water moving through the riverbank and infiltrating city wells was related to the frequency of virus detection in the wells.
"There is a misconception that groundwater is pure because it is filtered simply by the process of passing through the soil, but that isn't always the case," said Mark Borchardt, Ph.D., the study's lead investigator and a scientist in MCRF's National Farm Medicine Center. "Understanding viruses in groundwater is a research priority among drinking water professionals. La Crosse is leading the way and has the most extensive dataset of any community in the U.S. that uses groundwater as its drinking water source."
Researchers tested 48 untreated water samples from six of the city's 15 wells to evaluate whether viruses were present in the raw water. Half of the water samples contained at least one type of gastrointestinal virus and 23 percent of the samples contained two or more virus types.
The study found enteroviruses, rotavirus, hepatitis A virus and noroviruses. Besides noting the presence of these viruses with molecular testing methods, researchers attempted to culture the enteroviruses and hepatitis A viruses to see if they were infectious. None of the enteroviruses sampled were infectious, althoug
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Contact: Chris Schellpfeffer
cschell@lsb.com
608-251-7070
Marshfield Clinic
6-Oct-2004