Epidemiology of enteroaggregative Escherichia coli infections and associated outcomes in the MAL-ED birth cohort

Abstract

BackgroundEnteroaggregative E. coli (EAEC) have been associated with mildly inflammatory diarrhea in outbreaks and in travelers and have been increasingly recognized as enteric pathogens in young children with and without overt diarrhea. We examined the risk factors for EAEC infections and their associations with environmental enteropathy biomarkers and growth outcomes over the first two years of life in eight low-resource settings of the MAL-ED study.MethodsEAEC infections were detected by PCR gene probes for aatA and aaiC virulence traits in 27,094 non-diarrheal surveillance stools and 7,692 diarrheal stools from 2,092 children in the MAL-ED birth cohort. We identified risk factors for EAEC and estimated the associations of EAEC with diarrhea, enteropathy biomarker concentrations, and both short-term (one to three months) and long-term (to two years of age) growth.ResultsOverall, 9,581 samples (27.5%) were positive for EAEC, and almost all children had at least one detection (94.8%) by two years of age. Exclusive breastfeeding, higher enrollment weight, and macrolide use within the preceding 15 days were protective. Although not associated with diarrhea, EAEC infections were weakly associated with biomarkers of intestinal inflammation and more strongly with reduced length at two years of age (LAZ difference associated with high frequency of EAEC detections: -0.30, 95% CI: -0.44, -0.16).ConclusionsAsymptomatic EAEC infections were common early in life and were associated with linear growth shortfalls. Associations with intestinal inflammation were small in magnitude, but suggest a pathway for the growth impact. Increasing the duration of exclusive breastfeeding may help prevent these potentially inflammatory infections and reduce the long-term impact of early exposure to EAEC.

Mixed Aetiology of Diarrhoea in Infants Attending Clinics in the North-West Province of South Africa: Potential for Sub-Optimal Treatment

“…These pathotypes are known agents of traveller's diarrhoea [71,72]. Though they are frequently isolated in asymptomatic cases, reports have shown that even in the absence of diarrhoea, they are associated with intestinal inflammation, which may impact child's development [73]. In developing countries, the prevalence of EAEC pathotypes among diarrhoea cases ranges from 4.5% to 41% [69,71,74,75].…”

Antibiotic Resistance Profile and Clonality of E. coli Isolated from Water and Paediatric Stool Samples in the North-West, Province South Africa

“…However, some strains have acquired pathogenic potentials allowing them to cause diarrhoea (intestinal pathotypes) and other systemic illnesses involving the urinary tract, brain and blood (extra intestinal pathotypes) 1 . Intestinal or diarrhoeagenic E. coli (DEC) strains constitute the primary diarrhoea aetiologic agents in children younger than five years old 2,3 and in most cases, they are associated with growth defects 4 . About 760,000 children lose their lives every year to diarrhoeal diseases worldwide 5 .…”

“…EAEC members have been reported to cause inflammation of the intestines in children and impairing their growth and negatively impacting their development even without diarrhoea 4 . EAEC virulence genes are heterogeneous.…”

“…EAEC virulence genes are heterogeneous. The pathogenesis and genes encoding virulence factors in these strains are not uniform but show a considerable degree of variability among strains 4,14 . Nonetheless, the plasmid-borne aggR gene has been characterised and reported as the most common gene associated with EAEC pathotypes, and it regulates the virulence genes encoded in the chromosomes, plasmid and the type VI secretion system 4 .…”

Diarrea persistente en la población infantil

“…El patotipo EAEC fue hallado en niños con cuadros agudos, prolongados y persistentes. La presencia de este patógeno en niños con diarrea del cuadro está en coincidencia con numerosas investigaciones (Nguyen et al, 2006;Al-Gallas et al, 2007;Okeke et al, 2009;Jafari et al, 2009;Rajendran et al, 2010;Kaur et al, 2010;Kermani et al, 2010;Croxen et al, 2013;Hebbelstrup Jensen et al, 2014;Tobías et al, 2015;Tian et al, 2016;Schilling et al, 2017;Rogawski et al, 2017).…”