VIRUSES THAT MULTIPLY IN THE GUT AND CAUSE ENDEMIC AND EPIDEMIC GASTROENTERITIS

Background: Acute infectious diarrhea in young children is a leading c ause of morbidity and mortality in developing countries. Even in devel oped countries, infectious enteritis is second only to respiratory inf ections as a cause of morbidity in early childhood. Objective: To nomi nate the various viral agents that cause enteritis, discuss the pathog enesis, clinical features, epidemiology and diagnostic procedures empl oyed. Study design: Pertinent literature was reviewed and the findings of investigations carried out on viral enteritis by various colleague s recalled. Results: The viruses causing gastroenteritis include: Rota viruses; Adenoviruses-especially Ad 31, Ad 40 and Ad 41; members of th e Caliciviridae, e.g. Norwalk virus, Hawaii virus, Snow Mountain virus , Taunton virus, Southampton virus, Toronto virus (formerly mini-reovi rus) and others; Astrovirus; Coronavirus; Torovirus; Cytomegalovirus ( CMV) and possibly Picobirnavirus. Enteritis-producing viruses replicat e in columar epithelial cells in the distal parts of villi of the smal l intestine. Two mechanisms are addressed to explain why diarrhea occu rs. Clinically, the main expression of illness is a watery diarrhea th at lasts 24 h to about 7 days. Vomiting is of shorter duration and may not always accompany the diarrhea. Fever is generally less than or eq ual to 38.5 degrees C. Virus is shed in the stool for about 3-7 days. Diagnostic procedures employ electron microscopy (EM), immune electron microscopy (IEM), enzyme-linked immunosorbent assay (ELISA), time-res olved fluoroimmunoassay (TR-FIA), latex agglutination, polyacrylamide gel electrophoresis (PAGE) and the polymerase chain reaction (PCR). Co nclusion: In developed countries viral enteritis among young children may be up to three times more common than bacterial gut disease. With the exception of CMV enteric involvement, the stool is characteristica lly not bloody and white blood cells are not found. Patient management map involve the employment of IV replacement therapy to counter dehyd ration and electrolyte imbalance. Milder cases may be managed with ora l rehydration.