Pathogenic Escherichia coli Among Asymptomatic Children and Associated Factors

Although Escherichia coli is a part of the commensal flora of the gastrointestinal tract, pathogenic types of E. coli can cause diarrhea, especially in children. Pathogenic types are found also in healthy individuals, but prevalence of pathogenic E. coli among asymptomatic children varies and has not been studied in Latvia. The aim of the study was to determine prevalence of pathogenic E. coli among asymptomatic children and identify factors associated with presence of bacterium. Children (aged 0.5–8 years) without acute gastrointestinal symptoms were included in a cross-sectional study. Parents were asked to answer a questionnaire (demographic data, parental education, type of delivery, breastfeeding, antibacterial therapy, and allergic diseases) and bring a faecal sample of their child. The prevalence of pathogenic E. coli was detected by polymerase chain reaction and analysed in respect to risk factors. Statistical analyses included Chi-Square test, one-way ANOVA, and logistic regression. The patient sample group contained 245 children, mean age 4.5 SD ± 2.1; 46.5% (114/245) had allergies. In total, 16% (39/245) of isolates were positive for pathogenic E. coli. Prevalence of pathogenic types of E. coli was significantly higher among children without allergy compared to children with allergy: 21% (27/131) vs. 11% (12/114), p = 0.03. Prevalence did not differ significantly in respect to other studied factors. In logistic regression analysis pathogenic E. coli positivity was inversely associated with presence of allergy (OR = 0.45, CI: 0.21–0.94, p = 0.03). Asymptomatic carriage of pathogenic E. coli was identified in our paediatric patient sample and was inversely associated with an allergic disease. Microbiota changes related to pathogenic E. coli, as well as duration of carriage of bacterium, should be studied further.