Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Noroviruses are a genetically diverse group of single-stranded RNA, non enveloped viruses in the Caliciviridae family. Affecting people of all ages, Noroviruses are the commonest cause of viral gastroenteritis in humans. After infection, immunity to norovirus is usually incomplete and temporary. Learn more about noroviruses, their types, and effects on human health in this book.