Citation:

Brinkman, N. IT'S IN THE CHIPS: DEVELOPMENT OF A MICROARRAY GENECHIP APPROACH TO DETE T AND TYPE WATERBORNE VIRUSES. Presented at EPA Science Forum 2004, Washington, DC, June 1-3, 2004.

Impact/Purpose:

Overarching Objectives and Links to Multi-Year Planning

This task directly supports the Drinking Water Research Program Multi-Year Plan's long term goal to "develop scientifically sound data and approaches to characterize and manage risks to human health posed by exposure to waterborne pathogens and chemicals" under GRPA Goal 2 (Clean and Safe Water). The overarching objective is to provide the Office of Water, Agency risk assessors and managers, academics, the scientific community, state regulators, water industry and industry spokes groups with exploratory occurrence and exposure data on human enteric viruses. These data will improve the quality of risk-based assessments and tools used by the Agency to set regulations, policies and priorities for protecting human health and allow the Agency to assure the public that the appropriate methods are being used to demonstrate that drinking water is safe from pathogenic agents.

Specific Subtask Objectives:

o Conduct an exploratory occurrence studies on emerging human waterborne pathogenic viruses and viruses on the Contaminant Candidate List (CCL) in water (Subtask A; to be completed by 9/05 in support of LTG 1 (due 2010)).

o Determine the relationship of bacterial virus indicators to human enteric virus occurrence in the above studies (Subtask A; to be completed by 9/05 in support of LTG 1 (due 2010)).

o Develop a non-invasive assay for measuring human exposure to viruses (Subtask B; to be completed by 9/05 in support of LTG 1 (due 2010)).

Description:

Human caliciviruses, specifically members of the genus Norovirus, have been documented as a culprit for drinking water-related outbreaks of acute gastroenteritis in the United States. In addition, these viruses are believed to be one of the major causes of waterborne disease. Due to the potential risk these viruses pose to the public, they have been placed on the EPA's Contaminant Candidate List (CCL). The CCL was initiated in response to the 1996 Amendment to the Safe Drinking Water Act to aid in setting priorities of unregulated microbiological and chemical contaminants in the Agency's drinking water program. The CCL is published in the Federal Register (63 FR 10274).

Despite the fact that Noroviruses are highly infectious to people of all ages, qualitative risk assessments have been hindered because these viruses cannot be cultured by traditional methods, nor can they be cultivated through an animal model. Methods for identifying Noroviruses currently rely on molecular approaches, such as Reverse-Transcriptase-Polymerase Chain Reaction (RT-PCR) followed by product confirmation via hybridization with genogroup probes. Although this approach works, it is not conducive to specific Norovirus subtype identification in a timely fashion. Subtyping is important since it will allow waterborne isolates to be compared to clinical specimens in outbreak situations for identification of the source of contamination. In addition, it has been proposed that Norovirus subtypes may differ in their virulence properties. If this is the case, subtype identification will aid in accurately assessing the risk posed by these viruses. Subtyping can rapidly be achieved using a microarray platform. Affymetrix's GenFlex GeneChip allows the flexibility of designing a microarray to type Norovirus isolates in a high throughput and time-effective manner. While this technique is in the evaluation phase, the data shows that it is likely to be a valuable tool for typing viruses.

Record Details: