![]() ![]() ![]() If shellfish are shown to contain high levels of E. viruses) in shellfish exist, these have yet to be incorporated into EU legislation due to the lack of a robust evidence base and disagreements over what new standards should be introduced ( Lees and Cen WG6 TAG4, 2010 Hassard et al., 2017 EFSA, 2019). While methods for the detection and quantification of pathogens (e.g., Vibrio spp. However, studies have indicated that monitoring fecal indicator bacteria in shellfish may be a poor indicator of water pollution and the risk of human exposure to pathogens from consuming shellfish ( Gerba et al., 1979 Romalde et al., 2002 Younger et al., 2018). For example, within the European Union (EU), shellfish harvesting areas are classified according to the concentration of fecal indicator bacteria ( Escherichia coli) as designated in Annex II of EU Regulation 854/2004 ( EU, 2004). This has led to the formulation of legislation based on the measurement of fecal indicator bacteria ( EU, 2020). Therefore, raw and undercooked shellfish can act as vectors of infectious pathogens which can pose a serious risk to human health ( Flannery et al., 2014 Santos-Ferreira et al., 2020).īacterial species are traditionally used as indicators of fecal contamination of agricultural products, shellfish and shellfish waters ( Garcia et al., 2020). In many parts of the world, shellfish are grown in areas exposed to treated or untreated wastewater which may also contain human pathogens (e.g., Cryptosporidium, hepatitis A/E, norovirus Razafimahefa et al., 2020). Microbiological contamination of molluscan shellfish can readily occur in areas where coastal waters are polluted with sewage effluent, and agricultural run-off, such that shellfish accumulate large amounts of bacterial or viral pathogens ( Bosch et al., 1995 Burkhardt and Calci, 2000 Winterbourn et al., 2016). Sustainable shellfish production, however, relies on the presence of clean water that is free from both organic and inorganic pollutants ( Mohebbi-Nozar et al., 2014 Blanco, 2018 Enuneku et al., 2018). In addition, shellfish consumption is becoming an increasingly important part of the human diet and is seen as an area for expansion and economic growth in many countries ( Oehlenschlager, 2012 Silver, 2014 Bostock et al., 2016). Globally, 18 million tons of marine molluscs are harvested each year with an estimated value of $35 billion, comprising 9% of the value of fisheries worldwide ( Wijsman et al., 2019 FAO, 2020). ![]() We conclude that current EU standards for evaluating microbiological risk in shellfish are inadequate for protecting consumers against exposure to human norovirus GII found in polluted marine waters. coli from shellfish tissue, but failed to eradicate NoV GII RNA. Depuration (72 h) in clean water proved partially successful at removing both pathogenic and non-pathogenic E. All three microbiological indicators accumulated rapidly in the mussels, reaching close to maximum concentration within 3 h of exposure, demonstrating that short CSO discharges pose an immediate threat to shellfish harvesting areas. We simulated water contamination after a point-source release from a combined sewer overflow (CSO) where untreated wastewater is released directly into the coastal zone. coli, NoV GII) after exposure of mussels ( Mytilus edulis) to water contaminated with human feces. coli O157:H7 and norovirus GII (NoV GII) RNA were evaluated using a combination of culture-based ( E. To evaluate the robustness of this approach, the accumulation, retention, and depuration of non-pathogenic E. The fecal indicator organism (FIO) Escherichia coli is frequently used as a general indicator of sewage contamination and for evaluating the success of shellfish cleaning (depuration) processes. ![]()
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