Epidemiology of Enteroaggregative, Enteropathogenic, and Shiga Toxin–Producing<i>Escherichia coli</i>Among Children Aged &lt;5 Years in 3 Countries in Africa, 2015–2018: Vaccine Impact on Diarrhea in Africa (VIDA) Study
John B. Ochieng, Helen Powell, Ciara E Sugerman, Richard Omore, Billy Ogwel, Jane Juma, Alex O Awuor, Samba O. Sow, Doh Sanogo, Uma Onwuchekwa, Adama Mamby Keita, Awa Traoré, Henry Badji, M. Jahangir Hossain, Joquina Chiquita M Jones, Irene N Kasumba, Dilruba Nasrin, Anna Roose, Yuanyuan Liang, Leslie P Jamka, Martín Antonio, James A Platts-Mills, Jie Liu, Eric R. Houpt, Eric D. Mintz, Elizabeth Hunsperger, Clayton Onyango, Nancy Strockbine, Marc‐Alain Widdowson, Jennifer R. Verani, Sharon M. Tennant, Karen L. Kotloff
Abstract
BACKGROUND: To address knowledge gaps regarding diarrheagenic Escherichia coli (DEC) in Africa, we assessed the clinical and epidemiological features of enteroaggregative E. coli (EAEC), enteropathogenic E. coli (EPEC), and Shiga toxin-producing E. coli (STEC) positive children with moderate-to-severe diarrhea (MSD) in Mali, The Gambia, and Kenya. METHODS: Between May 2015 and July 2018, children aged 0-59 months with medically attended MSD and matched controls without diarrhea were enrolled. Stools were tested conventionally using culture and multiplex polymerase chain reaction (PCR), and by quantitative PCR (qPCR). We assessed DEC detection by site, age, clinical characteristics, and enteric coinfection. RESULTS: Among 4840 children with MSD and 6213 matched controls enrolled, 4836 cases and 1 control per case were tested using qPCR. Of the DEC detected with TAC, 61.1% were EAEC, 25.3% atypical EPEC (aEPEC), 22.4% typical EPEC (tEPEC), and 7.2% STEC. Detection was higher in controls than in MSD cases for EAEC (63.9% vs 58.3%, P < .01), aEPEC (27.3% vs 23.3%, P < .01), and STEC (9.3% vs 5.1%, P < .01). EAEC and tEPEC were more frequent in children aged <23 months, aEPEC was similar across age strata, and STEC increased with age. No association between nutritional status at follow-up and DEC pathotypes was found. DEC coinfection with Shigella/enteroinvasive E. coli was more common among cases (P < .01). CONCLUSIONS: No significant association was detected between EAEC, tEPEC, aEPEC, or STEC and MSD using either conventional assay or TAC. Genomic analysis may provide a better definition of the virulence factors associated with diarrheal disease.