Environmental virological monitoring for the epidemiological surveillance and risk assessment

Waters represent the main vehicle of spreading for the human enteric viruses that can survive longer in the environment than the majority of enteric non sporogenic bacteria, and have a lower infective dose. The different uses of water, like drinking, irrigating, bathing, and growing food (i.e. shellfishes) can frequently expose people to enteric viral infections. Therefore, water virological monitoring could constitute an important instrument both for the epidemiological surveillance and for the risk assessment. At present, knowledge on virological contamination of waters is still incomplete owing to the technical difficulties in virus detection, that limit the possibility of monitoring to few specialized laboratories and then obstacle a very large spread of this kind of investigation. Besides that, the number of possible viral species to be detected is very large and will become even larger in the future as knowledge about viral environmental spread will increase. The advent of molecular biology techniques (mostly PCR) has opened new possibilities for virological environmental monitoring, allowing to detect non culturable agents and to perform molecular epidemiology studies. However many questions remain still unsolved: the standardization of detection methods, the choice of the most significant agents for risk assessment, the selection of a reliable indicator for viral contamination, and so on. For this reasons we planned a study aimed to analyse the human enteric viruses environmental spread and its relations with virological diagnosis of gastroenteritis, to identify the most frequent viral pathogens in different types of water and to evaluate the possible correlations between pathogenic enteric viruses and commonly used faecal indicators.