New approaches for the quantitative detection of human pathogenic viruses within the freshwater-marine continuum

Viruses pose one of the biggest threats to human wellbeing being responsible for numerous infections and millions of deaths worldwide each year. Most of these viral diseases are passed via the faecal-oral route in which contaminated food and water are frequently implicated in the primary infectivity phase. Although many of these infections are self-limiting, the societal and economic burden should not be underestimated. For example, Norovirus (NoV) is estimated to cause over 2 million cases of illness in the UK each year resulting in millions of days of lost productivity and an economic burden estimated to exceed £100 million to the NHS directly and over £2 billion annually to the wider economy. Worryingly, it is clear from a range of critical reviews that the burden of waterborne disease is likely to increase in Europe in response to climate change. This increasing problem is being exacerbated by increased pressure on wastewater infrastructure (due to population rise), sewer misconnections and a greater incidence of storms and flood events causing the release of untreated sewage (stormwater discharge) into river networks and the coastal zone. Considering the magnitude of the problem and the disease burden forecast for the near future, it is timely to develop new strategic approaches for mitigating against viral contamination and to develop new and improved risk assessment tools for protecting human health.

In view of this, our proposal aims to address the critical need to develop and validate new tools for the detection and surveillance of human pathogenic viruses in freshwater, estuarine and coastal environments. Specifically, we will design and test experimental and modelling tools to permit the robust recovery and quantification of viral populations from contrasting matrices (e.g. seawater, freshwater, sediments, effluent, shellfish). These tools will be designed to capture the viral populations in both space and time. We will focus on viruses of strategic importance from a human health perspective (e.g. Norovirus, Sapovirus, Hepatitis A/E), however, these will be placed in a wider context via metavirome analysis of RNA and DNA viral communities. These techniques will be deployed and demonstrated at the catchment-to-coast scale whilst simultaneously answering fundamental questions about the temporal and spatial dynamics of viral flow. This knowledge will be used to validate next generation mathematical models capable of predicting viral flow through the river network and coastal zone. Combined, this information will be used with key stakeholders (e.g. Cefas) in the implementation of new methods and guidelines for assessing infection risk (e.g. in recreational waters, beaches & shellfisheries) and for protecting human health.

Our proposal directly addresses the strategic aims of the NERC Environmental Microbiology and Human Health (EMHH) Programme. As requested by the call, we will provide "scientific evidence to support fast and efficient identification of pathogenic microorganisms in environmental media which can be used in appropriate tools and models for the protection of public health targeting the freshwater and coastal zone". The work is also directly relevant to the policy objectives and strategic aims of the Food Standards Agency, Defra and European Union (DG Sanco, and DG Mare).

This proposal is designed to protect human health from the ever present threat of viral infection that exists in the environment. For example, Norovirus is estimated to cause over 2 million cases of illness in the UK each year, resulting in millions of days of lost productivity and an economic burden estimated to exceed £100 million to the NHS directly and over £2 billion annually to the wider economy. A reduction in the disease incidence would therefore be of great benefit to the UK economy. To ensure our project has lasting impact, a range of key stakeholders have been actively engaged in the formulation and writing of this proposal to ensure that it directly meets their needs, complements existing research and is fit for purpose. Specifically, this proposal will be of benefit to water quality managers and regulators, both national and international. The main UK beneficiaries will be the Food Standards Agency, Cefas (Defra), Environment Agency, water companies, local authorities and the shellfish industry as well as UK academia. Internationally, the work will directly inform the European Environment Agency, EU-DG MARE and EU-DG SANCO, however, our project addresses an issue of global relevance, and therefore the impact will be far-reaching. Stakeholders will benefit as follows:

1. Human pathogenic viruses are rarely measured in river, estuarine and coastal waters and therefore are not used by the Environment Agency, Food Standards Agency or EU for regulatory purposes. Although ISO accredited methods of detection have been established by the team (e.g. NoV in shellfish by Cefas), uncertainty still remains on their detection in some matrices and additionally as to whether these PCR-detected viruses are still infective to humans. Therefore the formulation of regulatory standards for shellfish, bathing waters etc is currently a subject of considerable debate. As risk assessment must be based on robust scientific research, we will provide key underpinning data for policymakers and regulators.

2. Cefas work directly with the UK government and EU to monitor the marine environment and to demonstrate UK compliance with national and international marine legislation. A key part of Cefas' work is to detect and advise on the effects of anthropogenic drivers on the marine environment. Having Cefas embedded in the project will bring lasting benefits in ensuring that the information generated will have real impact. As an example, David Lees (Cefas) is Director of the European Union Reference Laboratory (EURL) monitoring bacteriological and viral contamination of bivalve molluscs which represents a primary forum for our findings. Our existing strong links with the UK Food Standards Agency and the European Union (Directorate-General for Maritime Affairs and Fisheries, DG-MARE; Directorate-General for Health and Consumer, DG-SANCO), the Consumers, Health and Food Executive Agency (CHAFEA), European Food Standards Agency (EFSA), European Centre for Environment and Human Health (ECEHH) means that we can disseminate and discuss the project findings with the regulatory and medical community through well-established channels.

3. Our project is highly relevant to water companies. Welsh Water are key stakeholders in our project while delivery to the wider water industry will be made through the UK Water Industries Research (UKWIR).

4. Key stakeholders are Public Health Wales, Public Health England and Scotland Public Health Network.

5. The Shellfish Association of Great Britain (SAGB) is an ideal vehicle to disseminate our findings to the shellfish industry and the aquaculture industry in general. Shelagh Malham attends regular SAGB meetings which bring together the shellfish industry including producers and processers, several government and non-governmental organisations and has lobby activity within Westminster for issues affecting the industry. This proposal addresses some of the top priority issues facing the industry.