Gastro-intestinal pathogens of recently discovered significance

Gastro-intestinal infection is an important cause of morbidity and mortality, particularly in children.Although significant advances have taken place in the diagnosis of gastroenteritis approximately 5 million deaths due to this condition occur each year in the developing world in children under 5 years.During the 1970s rotavirus was identified as one the most important pathogens in childhood diarrhoea increasing the specific diagnosis for diarrhoea from lo-20% to 40-70%.Since then a further diverse group of organisms have been implicated as gastrointestinal pathogens.Some like Helicobacter pylori are definitely pathogenic, whereas considerable controversy still surrounds the role of others such as Aeromonas and Plesiomonas in gastrointestinal disease.We review the clinical, epidemiological and laboratory features of these infections and discuss their importance in children. AeromonasAeromonas has been recognised as a pathogen in immunocompromised hosts since 1968.'There now exists a large body of mainly epidemiological evidence implicating Aeromonas as enteric pathogens in the normal host, particularly in children. MicrobiologyThe organisms are gram negative facultative anaerobic, motile, bacilli with a single flagellum.Three species are recognised -A.hydrophilia, A. sobria and A. caviae.Isolation of Aeromonas from stool requires a selective media supplemented with ampicillin to which, at