Bacterial gastroenteritis

Infectious diarrhoea is a major public health concern worldwide. In developing countries it leads to around two million deaths per year in the under-five age group alone. In developed countries diarrhoeal disease is rarely fatal, except at extremes of age or in the immunocompromised; however, it remains a cause of significant morbidity. Gastroenteritis refers to syndromes of diarrhoea or vomiting resulting from non-inflammatory infection in the upper small bowel or inflammatory infection in the colon, caused by bacteria, viruses, or parasites. In approximately half of suspected cases, no causal agent is identified. The prevalence of each pathogen varies with geographical region and population factors. Viruses are more common in infants and children, particularly in developed countries. Bacteria, the focus of this review, are responsible for 10–55% of diarrhoeal episodes, with highest rates occurring in the developing world. However, with increase in international travel and globalization of the food industry, we must be alert to pathogens more typical of the developing world. Increasing antibiotic resistance must also be considered when choosing empirical treatment. Advances in molecular and rapid detection of enteric pathogens hold promise of improved therapeutic, preventative and control strategies, although widespread introduction of novel diagnostics into clinical practice will require careful cost-benefit analyses.