Reducing the risk of viral contamination of the UK's food and water supply

Viruses pose one of the biggest threats to human health being responsible for numerous infections and millions of deaths worldwide each year. Most of these viral diseases are transmitted via the faecal-oral route in which contaminated food and water are directly or indirectly 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. A recent review also highlighted the lack of UK government funding allocated to NoV research relative to the number of cases and the cost of the disease, calling for much greater targeted research in this area. In addition to these well documented Caliciviridae, focus is also turning to new and emerging viruses that have either recently entered Europe (e.g. new variant Hantaviruses), soil/water-borne viruses implicated in triggering diseases such as cancer or hepatitis (e.g. HPVs and HPyVs, hepatitis E virus), or where established viruses have acquired greater virulence (e.g. NoV GII.4 Sydney). It is clear from a range of critical reviews that the burden of soil and waterborne disease is likely to increase in Europe in response to climate change. This increasing problem is being exacerbated by increased pressure to apply more wastewater sludges back to land. Further, stress on wastewater infrastructure (due to population rise), sewer misconnections and a greater incidence of storms and flood events is causing the release of untreated sewage (stormwater discharge) onto floodplain soils. In summary, water- and food-borne viral infections are here to stay and the problem is expected to get worse in the coming decades due to climate change and socioeconomic pressures.