Table 3.

Summary of Data Reported in Birth Cohort Studies on Coinfections by Other Enteropathogens and Norovirus-attributable Incidence of Pathogen-attributable Diarrhea

Birth Cohort [Reference]	Enteropathogens Investigated	Major Findings Related to Coinfections and Norovirus-attributable Incidence
MAL-ED [29–32]	Rotavirus, adenovirus, astrovirus, Aeromonas, Campylobacter, EAEC, EIEC, atypical EPEC, typical EPEC, ETEC, Plesiomonas, STEC, Salmonella, Shigella, Vibrio, Yersinia, Cryptosporidium, Giardia, Entamoeba histolytica. Expanded study [32] used TaqMan array cards and expanded targets to include 11 additional microorganisms: sapovirus, Helicobacter, Enterocytozoon, Encephalitozoon, Cyclospora, Cystoisospora, Ancylostoma, Ascaris, Necator, Strongyloides, Trichuris	•  After Campylobacter spp. and enterovirulent Escherichia coli, norovirus was the third most common pathogen detected in 7077 diarrheal stools collected among 1457 children in the global MAL-ED collaborative, with detection rates of 41%, 40%, and 23%, respectively •  78% of norovirus-positive diarrheal stools were also positive for copathogens • Campylobacter, EAEC, Giardia, and ETEC were the most common copathogens among 1607 norovirus-positive diarrheal stools (43%, 24%, 19%, and 12%, respectively) • In the first and second years of life, the norovirus-attributable fraction was 5%–6% • Norovirus-attributable incidences were 16.4 (95% CI, 13.7–22.6) and 15.4 (95% CI, 12.5–20.1) attributable episodes per 100 child-years for the first year and first 2 years of life • Genogroup I norovirus infections were not attributable to diarrheal disease
Peru [24, 25]	Rotavirus, sapovirus	• 4% (2/54) and 7% (4/54) of norovirus-positive asymptomatic and diarrheal stools were rotavirus positive • 4 diarrheal stools tested sapovirus-positive
Chile [23]	Rotavirus, sapovirus, Salmonella, Shigella, Campylobacter, Yersinia	• 0.2% (4/2278) of asymptomatic norovirus-positive stools were coinfected with rotavirus • 4% (1/26) of symptomatic norovirus-positive stools were coinfected with Campylobacter • Diagnostic methods may lack sensitivity
India [20]	Rotavirus, Aeromonas, Vibrio, Shigella, Giardia, Cryptosporidium, Ascaris	• 27% (56/207) of norovirus-associated diarrheal stools contained coinfections • The most common coinfections were rotavirus, Giardia, and Cryptosporidium (17% [36/207], 4% [9/207], and 2% [5/207], respectively)
Vietnam [35]	Rotavirus, Shigella, Campylobacter, Salmonella	• Of the 1309 diarrheal stools available, detection rates for rotavirus, norovirus, Campylobacter, Salmonella, and Shigella were 30%, 13%, 12%, 10%, and 9%, respectively. • 15% (192/1309) of stools were positive for >1 pathogen • At least 1 additional pathogen was detected in 50% (88/176) of norovirus-positive stools
Bangladesh [26]	Rotavirus, adenovirus, astrovirus, sapovirus, Campylobacter, EAEC, EPEC, ETEC, STEC, Salmonella, Shigella/EIEC, Vibrio, Yersinia, Enterocytozoon, Encephalitozoon, Cyclospora, Cystoisospora, Cryptosporidium, Giardia, E. histolytica, Ancylostoma, Ascaris, Necator, Strongyloides, Trichuris	• Roughly 10% of stools (for each diarrheal and routine) tested positive for norovirus. • Attributable fractions were highest for Campylobacter, EAEC, EPEC, and rotavirus.
Bangladesh [36]	Rotavirus, adenovirus, astrovirus, sapovirus, Aeromonas, Bacteroides fragilis, Campylobacter (spp. jejuni, coli), Clostridium difficile, EAEC, Shigella/EIEC, atypical EPEC, typical EPEC, ETEC, STEC, Helicobacter pylori, Salmonella, Vibrio cholerae, Cyclospora cayetanensis, Cystoisosporiasis belli, Cryptosporidium, Giardia, Entamoeba histolytica, Enterocytozoon bieneusi, Encephalitozoon intestinalis, Ancylostoma duodenale, Ascaris lumbricoides, Necator americanus, Strongyloides stercoralis, Trichuris trichiura	• Of the 1741 episodes of diarrhea, norovirus was detected in ~20% • Norovirus ranked sixth (~90 attributable episodes) among the 32 enteropathogens attributable to diarrhea among children in the first year of life. • Preceding norovirus in ranking were C. jejuni/coli, rotavirus, adenovirus 40/41, Shigella/EIEC, and STEC associated with 187.4, 181.5, 142.3, 124.7, and 107.5 attributable episodes, respectively, during the first year of life

Abbreviations: CI, confidence interval; EAEC, enteroaggregative Escherichia coli; EIEC, enteroinvasive Escherichia coli; EPEC, enteropathogenic Escherichia coli; ETEC, enterotoxigenic Escherichia coli; MAL-ED, Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development; STEC, Shiga toxin–producing Escherichia coli.