Background

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. In addition, some viruses spread through respiratory or other bodily fluids but are still emitted via faeces (e.g. SARS-CoV-2, RSV, Influenza),

For example, COVID-19 can be spread from respiratory infections and its worldwide impact has been rapid and catastrophic. On a lesser scale, 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.

In addition to these well documented viruses like SARS-CoV-2 and NoV, focus is also turning to new and emerging viruses that have either recently entered Europe (e.g. new variant Hantaviruses), vaccine-escaping viruses (e.g. rotavirus), water-borne viruses implicated in triggering diseases such as cancer or hepatitis (e.g. human papilloma- and polyomaviruses, 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 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.

In addition, new tools are needed to monitor the prevalence of human infections in the population as new viruses emerge (i.e. public health surveillance).

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. In response to the problem highlighted above, a key challenge is to be able to rapidly quantify key pathogenic viruses in environmental samples, evaluate the potential risk they pose to human health and, where needed, develop measures to mitigate against infection and spread.

The VIRAQUA, UK and Welsh Government and BlueAdapt projects all aim to address the critical need to develop and validate new tools for the detection and surveillance of human pathogenic viruses in wastewater, freshwater and coastal environments. Specifically, we are looking to build national capability for viral and AMR surveillance to meet the needs of the national One Health agenda. Wastewater-based epidemiology represents a new and emerging tool to help address public and environmental health needs both in the UK and internationally.