Antibiotic-associated diarrhoea: an overlooked aetiology?

Sixty-three faeces samples from hospital in-patients with probable antibiotic-associated diarrhoea (AAD) are investigated. All samples are examined for routine bacterial enteric pathogens, pus cells, red blood cells and parasites. The samples are also screened for Clostridium difficile cytotoxin B (CDT), C. perfringens enterotoxin and Candida spp. (by microscopy and quantitative culture). Faecal samples from two control groups (healthy volunteers and community samples from GP patients) are also screened. A possible pathogen was found in 71% of AAD cases. Candida spp. overgrowth was the most common (44.4%), followed by CDT (34.9%) and Clostridium perfringens enterotoxin (9.5%). There was good agreement between the significant Gram films and quantitative Candida spp. culture (kappa=0.683). Clinical information revealed the majority of patients were on multiple antibiotic regimes, receiving 'high risk' antibiotics. Of community samples, 21% were positive for Clostridium perfringens enterotoxin, indicating that C. perfringens is a problem in the community, not necessarily associated with antibiotic use. The results suggest that quantitative Candida spp. culture should be performed on all specimens requesting AAD investigations.