Chapter 19 - Noroviruses, Sapoviruses, and Aichi Viruses Emergence in Wastewater Associated With Viral Pandemic Gastroenteritis

Abstract

Gastroenteric viruses such as noroviruses, sapoviruses, and Aichi viruses are considered as the most common pathogens associated with human viral gastroenteritis in the world. These three emerging gastroenteric viruses are frequently identified in wastewater and represent the most frequent source of foodborne and waterborne illnesses. Noroviruses are considered the second etiological agent of acute viral gastroenteritis in children. Similarly, noroviruses, sapoviruses, and Aichi viruses are considered emerging viruses associated with viral pandemic gastroenteritis. In addition, the high genetic diversity and the type of the nucleic acid genome (RNA) of these viruses are responsible for the emergence of new genogoups and genotypes in the pediatric population, and in the aquatic environment every 2–3 years. Moreover, Aichi viruses are considered as a good virological marker for viral contamination in natural environments. Therefore the detection of these viruses in the environment, especially in wastewater, and the identification of their genotype appear to be a novel approach to survey the emergence of a new norovirus, sapovirus, and Aichi virus strains in different regions in the world. This chapter will focus on the description of the virological characteristics of these emerging viruses such as noroviruses, sapoviruses, and Aichi viruses. An overview will cover the history, taxonomy, structure, genomic organization, replication cycle, genetic diversity, transmission mode, pathogenesis, immune response, diagnosis, and epidemiology of these viruses. The circulation and the distribution of a new genogroups and genotypes of noroviruses, sapoviruses, and Aichi viruses in wastewater treatment plants were also described. The transmission of these gastroenteric viruses into the receiving environments constitutes a serious public health danger and is of significant importance in environmental virology. Both clinical and environmental monitoring appears to be an appreciated policy to survey the noroviruses, sapoviruses, and Aichi virus emergent strains in regions that lack gastroenteric virus pandemic surveillance.