Assuming that climate change will affect the aquatic environment, water-borne micro-organisms will be impacted as well. Further, assuming that human-related viruses remain in the water circuit in spite of sewage treatment technologies that remove most of them, virus levels in the water will vary as a result of climate change. With virological data stemming from various environments, the project attempts to provide hydrological models to determine the effects of climate change on the variation in viral fluxes and therefore in the risk associated with viral diseases. It constitutes a novel approach dealing with water cycle monitoring.
To achieve this innovative integrated approach, three ways are explored. The project firstly focusses on improving routine tools for identifying and measuring virus levels in water. It attempts at the same time to establish methodologies for defining waterborne viruses as viral indicators of sewage pollution. It will then bring together this information with climate change predictions to model the evolution of pathogenic viruses’ concentrations according to climate scenarios.
There are currently few tools for quantitative virological monitoring. New quantitative methods have therefore been established. These are based upon molecular methods (i.e. polymerase chain reaction or PCR) that represent fast and specific tools. To refine the approach so that viruses from specific sources may be identified, researchers have developed molecular probes specific to animal viruses (such as cattle, pigs, sheep and birds) as well as to human types. Until now, standard operating protocols (SOPs) have been described and the associated relevant reagents have been produced. This methodology, called microbial source-tracking (or MST), allows researchers to determine the relative proportions of different viruses in complex mixes derived from animal and human sources.
Furthermore, based on this methodology, a new approach consists in considering viruses as pollution indicators complementary to faecal indicator bacteria, analysis for which is currently better known and most commonly performed. This is particularly relevant for monitoring sewage pollution and recreational bathing waters. Enteric viruses in particular have been recognized as agents that can cause gastro-intestinal disease but also more serious diseases such as hepatitis and meningitis. They are faecal-orally transmitted viruses and may be contracted when swimming or canoeing in polluted water. Their surveillance in recreational waters can therefore support health risk assessment by providing useful data on water quality.
Finally, to feed the mathematical models that aim to predict variations in virus concentrations due to climate change, five sites across the globe vulnerable to climate change are being studied ( in Sweden, Spain, Hungary, Greece and Brazil). All the information gathered from these target sites will be used to estimate changes in virus levels and to support strategic planning in water management. These models will either be derived from existing epidemiological models or generated de novo if necessary.
The project is co-financed by the European Commission under the Seventh Framework Programme (FP7), a grant funding programme. It is coordinated by the Aberystwyth University (United Kingdom). It is still running and will be achieved in 2013 so that the technology readiness level is estimated to 7 on the TRL scale.