The detection of Escherichia coli heat-labile enterotoxin by enzyme-linked immunosorbent assay

An enzyme linked immunosorbent assay (ELISA) technique was modified and used to detect heat-labile (LT) enterotoxigenic Escherichia coli (ETEC) from specimens of faeces sent to a routine diagnostic laboratory. Strains of LT ETEC were detected in eight of 250 (3.2%) diarrhoeal stools but were not found in 110 non-diarrhoeal stools. All eight patients found to have LT ETEC were travellers returning with diarrhoea. LT ETEC was the most common bacterial pathogen found (15.4%) in this group of patients, exceeding Campylobacter sp. (5.8%) and Salmonella sp. (7.7%). The ELISA technique was simple to perform and visual readings were found to be reliable.