Acute diarrhoea in adults: a prospective study.

A prospective study of 74 adults with acute diarrhoea was carried out in Sydney in 1984-1985 to determine the infective agents that were involved and their relationship to clinical, epidemiological and laboratory features. Thirty-four potential pathogens were identified in 32 (43.2%) patients. These included, in order of frequency: Campylobacter spp., rotavirus, Clostridium difficile, Salmonella enteritidis, Aeromonas hydrophila, Vibrio parahaemolyticus, adenovirus, a small round virus and Giardia lamblia. A seasonal trend was noted; the majority of Campylobacter isolations occurred in summer. The patients with Cl. difficile infection formed a distinct group, and experienced a subacute onset of diarrhoea after antibiotic administration, with few systemic symptoms. Except in these patients, the clinical and epidemiological features, together with results of faecal microscopy, were not a reliable predictor of the nature of the pathogens that were identified. While most patients with diarrhoea can be treated supportively, stool culture is an important procedure in patients with severe or protracted illness when specific antimicrobial therapy is contemplated.