Abstract. Among microorganisms, viruses are best fit to become emerging pathogens since they are able to adapt not only by mutation but also through recombination and reassortment and can thus become able to infect new hosts and to adjust to new environments. Enteric viruses are among the commonest and most hazardous waterborne pathogens, causing both sporadic and outbreak-related illness. The main health effect associated with enteric viruses is gastrointestinal illness, but they can also cause respiratory symptoms, conjunctivitis, hepatitis, central nervous system infections, and chronic diseases. Non-enteric viruses, such as respiratory and epitheliotrophic viruses are not considered waterborne, as they are not readily transmitted to water sources from infected individuals. The present review will focus on viral pathogens shown to be transmitted through water. It will also provide an overview of viruses that had not been a concern for waterborne transmission in the past, but that may represent potentially emerging waterborne pathogens due to their occurrence and persistence in water environments.Key words: viruses, waterborne, emerging, drinking water, recreational water.
Riassunto (Infezioni emergenti e potenzialmente emergenti in ambienti acquatici).I virus sono tra i principali agenti di infezioni emergenti, in quanto sono in grado di acquisire nuove caratteristiche biologiche attraverso fenomeni di mutazione, ricombinazione e riassortimento genico, adattandosi così a nuovi ospiti e nuove nicchie ecologiche. I virus enterici sono tra le principali cause di malattie infettive di origine idrica, che possono manifestarsi come casi sporadici o cluster epidemici. Le manifestazioni cliniche più comuni sono le gastroenteriti; tuttavia i virus enterici sono in grado di causare anche sintomi respiratori, congiuntiviti, epatiti, infezioni del sistema nervoso centrale e malattie croniche. La presente rassegna fornisce una panoramica dei virus enterici tradizionalmente associati alle malattie idrotrasmesse; mostra inoltre dati epidemiologici su alcuni gruppi di virus che non sono stati associati a malattie idrodiffuse in passato (inclusi virus respiratori ed epiteliotropici), ma che possono rappresentare nuovi patogeni emergenti a causa della loro presenza e persistenza in ambienti acquatici.Parole chiave: virus, malattie idrotrasmesse, patogeni emergenti, acque potabili, acque ricreative.