Epidemiological aspects of fecal colonization with P-fimbriated Escherichia coli in neonates.

Fecal colonization with P-fimbriated Escherichia coli has caused epidemic outbreaks of extraintestinal E. coli infections in the neonatal unit of Danderyd Hospital. The aerobic fecal flora was therefore studied in 1,955 newborn children born at Danderyd Hospital during a period of 2.5 years. E. coli was found in 58% of the maternity ward children and in 57% of the neonatal unit children. A P-fimbriated strain was found in 12% and 17% of the children, respectively (p less than 0.01). There was a significant increase in the frequency of children colonized with E. coli, and especially P-fimbriated E. coli, with length of stay in the neonatal unit. There was a statistical correlation between bed occupancy and colonization with P-fimbriated E. coli (r = 0.46, p less than 0.01) during this study period. We found an incidence of P-fimbriated E. coli of 10 to 20% among the E. coli strains isolated from the fecal specimens which we regard as the baseline incidence.