Aetiology of viral gastroenteritis: a review.

Over the past seven to eight years, several virus groups have been shown to be associated with gastroenteritis. They are adenoviruses, astroviruses, caliciviruses, coronaviruses. Norwalk-like viruses and rotaviruses. In infants and young children, rotaviruses are the single most important aetiological agents of acute gastroenteritis in terms of numbers of cases and also of patients requiring admission to hospital. In older children and adults, the aetiology is less clear, but the present state of our knowledge indicates that Norwalk-like viruses are one of the major causes. Most of these gastroenteritis-producing viruses cannot be propagated satisfactorily in laboratory cell-culture systems, and electron microscopy is the chief method of detection. Immune electron microscopy is used to demonstrate specific antibody increases during infection and to show antigenic differences between morphologically similar viruses. These techniques are relatively insensitive, and the development of a cell-culture system for the propagation of these "gastroenteritis viruses" would greatly facilitate epidemiological studies and vaccine development.