Astroviridae: A family of RNA viruses with two genera: MAMASTROVIRUS and AVASTROVIRUS. They cause GASTROENTERITIS in humans and also infect other vertebrates.Mamastrovirus: A genus of small, circular RNA viruses in the family ASTROVIRIDAE. They cause GASTROENTERITIS and are found in the stools of several vertebrates including humans. Transmission is by the fecal-oral route and there are at least eight human serotypes. The type species is Human astrovirus.Astroviridae Infections: Infections with ASTROVIRUS, causing gastroenteritis in human infants, calves, lambs, and piglets.