Enterotoxigenic Escherichia coli associated with infant diarrhoea in Galicia, north-western Spain.

To assess the role of enterotoxigenic Escherichia coli (ETEC) in infantile diarrhoea, 482 children with diarrhoea and 103 healthy controls, from three localities of Galicia, north-western Spain, were investigated between 1985 and 1988. Rotavirus (37.3%) and Salmonella spp. (12.8%) were the most common causal agents, followed by ETEC (3.9%), Campylobacter jejuni (2.3%), Shigella spp. (0.9%) and Yersinia enterocolitica (0.5%). ETEC were significantly more frequently isolated from children with diarrhoea who were under 1 month of age (26.5%) than from older diarrhoeic children (2.2%) (p less than 0.001) or from healthy children who were under 1 month of age (0%) (p less than 0.05). Among children who harboured ETEC, five of the nine children under 1 month of age developed diarrhoea in hospital, whereas none of the 10 children over 1 month of age did so. Seventeen ETEC isolates produced heat-stable enterotoxin (STa) only, four produced only heat-labile enterotoxin (LT), and two produced both toxins. Colonisation factor antigens CFA/I and CFA/II were detected in 11 (55.0%) of the 20 ETEC isolates that remained enterotoxigenic after maintenance in the laboratory. Most ETEC isolates belonged to serotypes O153:K-:H45 (nine STa+ CFA/I+ isolates), O27:K-:H7 (three STa+ isolates) or O6:K15:H16 (two LT+ STa+ CFA/II+ isolates). Our results suggest that ETEC constitute an important cause of neonatal diarrhoea in this part of Spain.