WATER RESOURCES RESEARCH GRANT PROPOSAL
Title: Concentration of Viral Particles from Water by Ultrafiltration (year 2 of 2 - continued)
Priority Problem Area: Water Quality Focus Category: Water Quality, Methods
Keywords: water-borne virus, viral concentration methods, ultrafiltration, viral contamination, enteroviruses, water quality
Duration: 24 months: July 1997 - June 1999
1999 WRIP Award: Total: $12,111
Principal Investigator: Kevin H. Oshima, Department of Biology, NMSU
Congressional District: New Mexico Second
Statement of Critical Resource Problem
In terms of drinking water safety, very little is know about the extent of viral contaminants in source (influent) and product (finished) drinking water and their relationship to disease. Critical to both identifying and quantitating viral contaminants is the detection and use of methods which reliably concentrate water-borne viral pathogens from drinking, surface and groundwater.
The Environmental Protection Agency (EPA) has mandated that large water utilities across the United States test their source and product water for viral pathogens for either surface or groundwater systems (EPA 1996). Although current methods for concentrating virus from these sources have allowed for the filtration of large volumes of water, there are difficulties in terms of 1) procedural complexity and 2) variable efficiency and consistency of virus recovery. Developing improved detection methods and then documenting the type and concentration viral pathogens from water is an ongoing area of interest from agencies such as the EPA, American Water Works Association (AWWA) and World Health Organization (WHO). There is growing concern for the potential health risks associated with the presence of viral pathogens in surface, ground and drinking water however, little data is available to determine how significant these risks are. Improvement in the ability to document the level of viral contaminants from the standpoint of detection sensitivity, reproducibility and consistency of results, simplification of the procedure and cost will make it more feasible to obtain results which are more analyzable and cost effective.
Statement of the Results, Benefits Expected
By the end of the funding period, an optimized method to recover viruses under controlled, laboratory scale conditions should be completed along with documentation to indicate the potential detection sensitivity and reproducibility with different viruses and water qualities for both a hollow fiber and tangential flow ultrafiltration system. As a result of these experiments, plans for scale-up and filtration under field conditions is anticipated using one or both of these systems. The objective is to develop an integrated unit (containing the filter, pumping system), with a reasonable flow capacity and cost.
With this data, long-term support from sources such as the EPA, AWWA, World Health Organization and filter manufacturers would be more feasible. These agencies have supported research to determine the level of risk to the human population from water borne viruses or in developing methods to provide needed information. In addition, there may be regional interest from the Southwest Center for Environmental Research and Policy (SCERP) for information on the virus levels in ground and surface water within the border region. The long-term objective is to use this system to develop a series of studies to determine the relationship between the level of viral contamination and documented cases of disease with possible enterovirus etiology. These methods can also be used to examine the utility of surrogate bacteriophage as an indicator for the presence of pathogenic viruses.
In addition to this proposal, I have a project underway to develop membrane-supported detection of viral agents by nucleic acid amplification which is currently supported in part by a major membrane manufacturer. The methods developed under the WRRI proposal will be used as the starting material for the detection of the viral pathogens by PCR and other nucleic acid amplification systems. Ultrafiltration may offer advantages in reducing the level of PCR inhibitors compared to the adsorption/elution method. Thus ultrafiltration will be examined not only from the standpoint of recovery of infectious virus particles but also for its affects and possible advantages for improving the efficiency of PCR amplification of target viral nucleic acid.