Current concepts in the evaluation, diagnosis and management of acute infectious diarrhea

Despite recent advances in our understanding of the pathogenesis of enteric diseases, acute infectious diarrhea remains a major cause of morbidity and mortality worldwide. Infection is the most common cause of acute diarrhea. Some causes of infectious diarrhea also result in serious long-term sequelae such as hemolytic uremic syndrome, Guillain-Barre syndrome and malnutrition. A better understanding of bacterial pathogenesis has grown increasingly important because of the emergence of new pathogens and the growing problems of resistance among enteric pathogens and other enteric flora. Non-antimicrobial approaches to therapy have become increasingly important with the emergence of serious antimicrobial resistance, such as vancomycin-resistant enterococcal colonization of the gastrointestinal tract. Finally, new understanding of how intestinal bacteria cause disease is revealing that enteric infections might trigger damage to epithelial cells or the intestinal barrier, or disrupt intestinal barrier and absorptive function (without necessarily causing overt diarrhea); thus, enteric infections might be far more important as emerging causes of malnutrition than has been previously appreciated. Therefore, diarrhea is both a cause and an effect of malnutrition. Treatment in most cases of bacterial and viral diseases consists of correcting fluid loss and electrolyte imbalance by oral or parenteral rehydration. Prevention of enteric illness by virtue of improved hygiene and provision of sanitation and water treatment is impractical in most developing countries, where morbidity and mortality rates are highest. For this reason, development of vaccines against the most important gastrointestinal infections remains a high priority.