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Background: The association between childhood diarrheal disease and linear growth faltering in developing countries is well described. However, the impact attributed to specific pathogens has not been elucidated, nor has the impact of recommended antibiotic treatment., Methods: The Global Enteric Multicenter Study enrolled children with moderate to severe diarrhea (MSD) seeking healthcare at 7 sites in sub-Saharan Africa and South Asia. At enrollment, we collected stool samples to identify enteropathogens. Length/height was measured at enrollment and follow-up, approximately 60 days later, to calculate change in height-for-age z scores (ΔHAZ). The association of pathogens with ΔHAZ was tested using linear mixed effects regression models., Results: Among 8077 MSD cases analyzed, the proportion with stunting (HAZ below -1) increased from 59% at enrollment to 65% at follow-up (P < .0001). Pathogens significantly associated with linear growth decline included Cryptosporidium (P < .001), typical enteropathogenic Escherichia coli (P = .01), and untreated Shigella (P = .009) among infants (aged 0-11 months) and enterotoxigenic E. coli encoding heat-stable toxin (P < .001) and Cryptosporidium (P = .03) among toddlers (aged 12-23 months). Shigella-infected toddlers given antibiotics had improved linear growth (P = .02)., Conclusions: Linear growth faltering among children aged 0-23 months with MSD is associated with specific pathogens and can be mitigated with targeted treatment strategies, as demonstrated for Shigella., (© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America.)

Diarrheal disease remains a major cause of childhood mortality and morbidity causing poor health and economic outcomes. In low-resource settings, young children are exposed to numerous risk factors for enteric pathogen transmission within their dwellings, though the relative importance of different transmission pathways varies by pathogen species. The objective of this analysis was to model associations between five household-level risk factors-water, sanitation, flooring, caregiver education, and crowding-and infection status for endemic enteric pathogens in children in five surveillance studies. Data were combined from 22 sites in which a total of 58,000 stool samples were tested for 16 specific enteropathogens using qPCR. Risk ratios for pathogen- and taxon-specific infection status were modeled using generalized linear models along with hazard ratios for all-cause diarrhea in proportional hazard models, with the five household-level variables as primary exposures adjusting for covariates. Improved drinking water sources conferred a 17% reduction in diarrhea risk; however, the direction of its association with particular pathogens was inconsistent. Improved sanitation was associated with a 9% reduction in diarrhea risk with protective effects across pathogen species and taxa of around 10-20% risk reduction. A 9% reduction in diarrhea risk was observed in subjects with covered floors, which were also associated with decreases in risk for zoonotic enteropathogens. Caregiver education and household crowding showed more modest, inconclusive results. Combining data from diverse sites, this analysis quantified associations between five household-level exposures on risk of specific enteric infections, effects which differed by pathogen species but were broadly consistent with hypothesized transmission mechanisms. Such estimates may be used within expanded water, sanitation, and hygiene (WASH) programs to target interventions to the particular pathogen profiles of individual communities and prioritize resources.

Background: The Global Enteric Multicenter Study (GEMS) was a 3-year case-control study that measured the burden, aetiology, and consequences of moderate-to-severe diarrhoea (MSD) in children aged 0-59 months. GEMS-1A, a 12-month follow-on study, comprised two parallel case-control studies, one assessing MSD and the other less-severe diarrhoea (LSD). In this report, we analyse the risk of death with each diarrhoea type and the specific pathogens associated with fatal outcomes., Methods: GEMS was a prospective, age-stratified, matched case-control study done at seven sites in Africa and Asia. Children aged 0-59 months with MSD seeking care at sentinel health centres were recruited along with one to three randomly selected matched community control children without diarrhoea. In the 12-month GEMS-1A follow-on study, children with LSD and matched controls, in addition to children with MSD and matched controls, were recruited at six of the seven sites; only cases of MSD and controls were enrolled at the seventh site. We compared risk of death during the period between enrolment and one follow-up household visit done about 60 days later (range 50-90 days) in children with MSD and LSD and in their respective controls. Approximately 50 pathogens were detected using, as appropriate, classic bacteriology, immunoassays, gel-based PCR and reverse transcriptase PCR, and quantitative real-time PCR (qPCR). Specimens from a subset of GEMS cases and controls were also tested by a TaqMan Array Card that compartmentalised probe-based qPCR for 32 enteropathogens., Findings: 223 (2·0%) of 11 108 children with MSD and 43 (0·3%) of 16 369 matched controls died between study enrolment and the follow-up visit at about 60 days (hazard ratio [HR] 8·16, 95% CI 5·69-11·68, p<0·0001). 12 (0·4%) of 2962 children with LSD and seven (0·2%) of 4074 matched controls died during the follow-up period (HR 2·78, 95% CI 0·95-8·11, p=0·061). Risk of death was lower in children with dysenteric MSD than in children with non-dysenteric MSD (HR 0·20, 95% CI 0·05-0·87, p=0·032), and lower in children with LSD than in those with non-dysenteric MSD (HR 0·29, 0·14-0·59, p=0·0006). In children younger than 24 months with MSD, infection with typical enteropathogenic Escherichia coli, enterotoxigenic E coli encoding heat-stable toxin, enteroaggregative E coli, Shigella spp (non-dysentery cases), Aeromonas spp, Cryptosporidium spp, and Entamoeba histolytica increased risk of death. Of 61 deaths in children aged 12-59 months with non-dysenteric MSD, 31 occurred among 942 children qPCR-positive for Shigella spp and 30 deaths occurred in 1384 qPCR-negative children (HR 2·2, 95% CI 1·2-3·9, p=0·0090), showing that Shigella was strongly associated with increased risk of death., Interpretation: Risk of death is increased following MSD and, to a lesser extent, LSD. Considering there are approximately three times more cases of LSD than MSD in the population, more deaths are expected among children with LSD than in those with MSD. Because the major attributable LSD-associated and MSD-associated pathogens are the same, implementing vaccines and rapid diagnosis and treatment interventions against these major pathogens are rational investments., Funding: Bill & Melinda Gates Foundation., (Copyright © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Background: Diarrheal diseases remain a leading cause of illness and death among children younger than 5 years in low-income and middle-income countries. The Global Enteric Multicenter Study (GEMS) has described the incidence, aetiology, and sequelae of medically attended moderate-to-severe diarrhoea (MSD) among children aged 0-59 months residing in censused populations in sub-Saharan Africa and south Asia, where most child deaths occur. To further characterise this disease burden and guide interventions, we extended this study to include children with episodes of less-severe diarrhoea (LSD) seeking care at health centres serving six GEMS sites., Methods: We report a 1-year, multisite, age-stratified, matched case-control study following on to the GEMS study. Six sites (Bamako, Mali; Manhiça, Mozambique; Basse, The Gambia; Mirzapur, Bangladesh; Kolkata, India; and Bin Qasim Town, Karachi, Pakistan) participated in this study. Children aged 0-59 months at each site who sought care at a sentinel hospital or health centre during a 12-month period were screened for diarrhoea. New (onset after ≥7 diarrhoea-free days) and acute (onset within the previous 7 days) episodes of diarrhoea in children who had sunken eyes, whose skin lost turgor, who received intravenous hydration, who had dysentery, or who were hospitalised were eligible for inclusion as MSD. The remaining new and acute diarrhoea episodes among children who sought care at the same health centres were considered LSD. We aimed to enrol the first eight or nine eligible children with MSD and LSD at each site during each fortnight in three age strata: infants (aged 0-11 months), toddlers (aged 12-23 months), and young children (aged 24-59 months). For each included case of MSD or LSD, we enrolled one to three community control children without diarrhoea during the previous 7 days. From patients and controls we collected clinical and epidemiological data, anthropometric measurements, and faecal samples to identify enteropathogens at enrolment, and we performed a follow-up home visit about 60 days later to ascertain vital status, clinical outcome, and interval growth. Primary outcomes were to characterise, for MSD and LSD, the pathogen-specific attributable risk and population-based incidence values, and to assess the frequency of adverse clinical consequences associated with these two diarrhoeal syndromes., Findings: From Oct 31, 2011, to Nov 14, 2012, we recruited 2368 children with MSD, 3174 with LSD, and one to three randomly selected community control children without diarrhoea matched to cases with MSD (n=3597) or LSD (n=4236). Weighted adjusted population attributable fractions showed that most attributable cases of MSD and LSD were due to rotavirus, Cryptosporidium spp, enterotoxigenic Escherichia coli encoding heat-stable toxin (with or without genes encoding heat-labile enterotoxin), and Shigella spp. The attributable incidence per 100 child-years for LSD versus MSD, by age stratum, for rotavirus was 22·3 versus 5·5 (0-11 months), 9·8 versus 2·9 (12-23 months), and 0·5 versus 0·2 (24-59 months); for Cryptosporidium spp was 3·6 versus 2·3 (0-11 months), 4·3 versus 0·6 (12-23 months), and 0·3 versus 0·1 (24-59 months); for enterotoxigenic E coli encoding heat-stable toxin was 4·2 versus 0·1 (0-11 months), 5·2 versus 0·0 (12-23 months), and 1·1 versus 0·2 (24-59 months); and for Shigella spp was 1·0 versus 1·3 (0-11 months), 3·1 versus 2·4 (12-23 months), and 0·8 versus 0·7 (24-59 months). Participants with both MSD and LSD had significantly more linear growth faltering than controls at follow-up., Interpretation: Inclusion of participants with LSD markedly expands the population of children who experience adverse clinical and nutritional outcomes from acute diarrhoeal diseases. Since MSD and LSD have similar aetiologies, interventions targeting rotavirus, Shigella spp, enterotoxigenic E coli producing heat-stable toxin, and Cryptosporidium spp might substantially reduce the diarrhoeal disease burden and its associated nutritional faltering., Funding: Bill & Melinda Gates Foundation., (Copyright © 2019 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Enteroaggregative Escherichia coli (EAEC) cause acute and persistent diarrhea, mostly in children worldwide. Outbreaks of diarrhea caused by EAEC have been described, including a large outbreak caused by a Shiga toxin expressing strain. This study investigated the association of EAEC virulence factors with diarrhea in children less than 5 years. We characterized 428 EAEC strains isolated from stool samples obtained from moderate-to-severe diarrhea cases (157) and healthy controls (217) children aged 0-59 months recruited over 3 years as part of the Global Enteric Multicenter Study (GEMS) in The Gambia. Four sets of multiplex polymerase chain reaction were applied to detect 21 EAEC-virulence genes from confirmed EAEC strains that target pCVD432 (aatA) and AAIC (aaiC). In addition, Kirby-Bauer disc diffusion antimicrobial susceptibility testing was performed on 88 EAEC strains following Clinical Laboratory Standard Institute guidelines. We observed that the plasmid-encoded enterotoxin [odds ratio (OR): 6.9, 95% confidence interval (CI): 2.06-29.20, P < 0.001], aggregative adherence fimbriae/I fimbriae (aggA) [OR: 2.2, 95% CI: 1.16-4.29, P = 0.008], and hexosyltransferase (capU) [OR: 1.9, 95% CI 1.02-3.51, P = 0.028] were associated with moderate-to-severe diarrhea among children < 12 months old but not in the older age strata (> 12 months). Our data suggest that some EAEC-virulent factors have age-specific associations with moderate-to-severe diarrhea in infants. Furthermore, our study showed that 85% and 72% of EAEC strains tested were resistant to sulphamethoxazole-trimethoprim and ampicillin, respectively. Sulphamethoxazole-trimethoprim and ampicillin are among the first-line antibiotics used for the treatment of diarrhea in The Gambia.

We report the clinical findings, epidemiology, and risk factors for moderate-to-severe diarrhea (MSD) associated with Aeromonas species in children 0-59 months of age, from the Global Enteric Multicenter Study, conducted at three sites in south Asia and four sites in sub-Saharan Africa. Children with MSD were enrolled along with controls matched for age, gender, and neighborhood. Pooled, age-stratified conditional logistic regression models were applied to evaluate the association of Aeromonas infection controlling for coinfecting pathogens and sociodemographic variables. A pooled, age-stratified, multivariate logistic regression analysis was done to identify risk factors associated with Aeromonas positivity in MSD cases. A total of 12,110 cases and 17,291 matched controls were enrolled over a period of 48 months. Aeromonas was identified as a significant pathogen in 736 cases of MSD in Pakistan and Bangladesh (22.2%). Aeromonas remained a significant pathogen even after adjustment for the presence of other pathogens and sociodemographic factors. Odds ratio (OR) for Aeromonas were higher in the presence of Shigella (matched OR: 6.2, 95% confidence interval [CI]: 1.9-20.2). Cases of Aeromonas were likely to present with dysentery, particularly in the 0-11 months (OR: 1.4, 95% CI 1.0-2.0) and 12-23 months (OR: 1.8, 95% CI: 1.3-2.5) age group. The odds of Aeromonas increased with increasing degree of stunting, being highest for severe stunting (OR: 10.1, 95% CI: 3.6-28.9). Aeromonas is a significant pathogen for MSD in Pakistan and Bangladesh. Presence of dysentery and co-occurrence with other pathogens, notably Shigella spp. are significant features of Aeromonas-associated diarrhea., Competing Interests: Farah Naz Qamar received research training support from the National Institute of Health's Fogarty International Center (1 D43 TW007585-01)., (© The American Society of Tropical Medicine and Hygiene.)

Background: Diarrhoea is the second leading cause of mortality in children worldwide, but establishing the cause can be complicated by diverse diagnostic approaches and varying test characteristics. We used quantitative molecular diagnostic methods to reassess causes of diarrhoea in the Global Enteric Multicenter Study (GEMS)., Methods: GEMS was a study of moderate to severe diarrhoea in children younger than 5 years in Africa and Asia. We used quantitative real-time PCR (qPCR) to test for 32 enteropathogens in stool samples from cases and matched asymptomatic controls from GEMS, and compared pathogen-specific attributable incidences with those found with the original GEMS microbiological methods, including culture, EIA, and reverse-transcriptase PCR. We calculated revised pathogen-specific burdens of disease and assessed causes in individual children., Findings: We analysed 5304 sample pairs. For most pathogens, incidence was greater with qPCR than with the original methods, particularly for adenovirus 40/41 (around five times), Shigella spp or enteroinvasive Escherichia coli (EIEC) and Campylobactor jejuni o C coli (around two times), and heat-stable enterotoxin-producing E coli ([ST-ETEC] around 1·5 times). The six most attributable pathogens became, in descending order, Shigella spp, rotavirus, adenovirus 40/41, ST-ETEC, Cryptosporidium spp, and Campylobacter spp. Pathogen-attributable diarrhoeal burden was 89·3% (95% CI 83·2-96·0) at the population level, compared with 51·5% (48·0-55·0) in the original GEMS analysis. The top six pathogens accounted for 77·8% (74·6-80·9) of all attributable diarrhoea. With use of model-derived quantitative cutoffs to assess individual diarrhoeal cases, 2254 (42·5%) of 5304 cases had one diarrhoea-associated pathogen detected and 2063 (38·9%) had two or more, with Shigella spp and rotavirus being the pathogens most strongly associated with diarrhoea in children with mixed infections., Interpretation: A quantitative molecular diagnostic approach improved population-level and case-level characterisation of the causes of diarrhoea and indicated a high burden of disease associated with six pathogens, for which targeted treatment should be prioritised., Funding: Bill & Melinda Gates Foundation., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: The importance of Cryptosporidium as a pediatric enteropathogen in developing countries is recognized., Methods: Data from the Global Enteric Multicenter Study (GEMS), a 3-year, 7-site, case-control study of moderate-to-severe diarrhea (MSD) and GEMS-1A (1-year study of MSD and less-severe diarrhea [LSD]) were analyzed. Stools from 12,110 MSD and 3,174 LSD cases among children aged <60 months and from 21,527 randomly-selected controls matched by age, sex and community were immunoassay-tested for Cryptosporidium. Species of a subset of Cryptosporidium-positive specimens were identified by PCR; GP60 sequencing identified anthroponotic C. parvum. Combined annual Cryptosporidium-attributable diarrhea incidences among children aged <24 months for African and Asian GEMS sites were extrapolated to sub-Saharan Africa and South Asian regions to estimate region-wide MSD and LSD burdens. Attributable and excess mortality due to Cryptosporidium diarrhea were estimated., Findings: Cryptosporidium was significantly associated with MSD and LSD below age 24 months. Among Cryptosporidium-positive MSD cases, C. hominis was detected in 77.8% (95% CI, 73.0%-81.9%) and C. parvum in 9.9% (95% CI, 7.1%-13.6%); 92% of C. parvum tested were anthroponotic genotypes. Annual Cryptosporidium-attributable MSD incidence was 3.48 (95% CI, 2.27-4.67) and 3.18 (95% CI, 1.85-4.52) per 100 child-years in African and Asian infants, respectively, and 1.41 (95% CI, 0.73-2.08) and 1.36 (95% CI, 0.66-2.05) per 100 child-years in toddlers. Corresponding Cryptosporidium-attributable LSD incidences per 100 child-years were 2.52 (95% CI, 0.33-5.01) and 4.88 (95% CI, 0.82-8.92) in infants and 4.04 (95% CI, 0.56-7.51) and 4.71 (95% CI, 0.24-9.18) in toddlers. We estimate 2.9 and 4.7 million Cryptosporidium-attributable cases annually in children aged <24 months in the sub-Saharan Africa and India/Pakistan/Bangladesh/Nepal/Afghanistan regions, respectively, and ~202,000 Cryptosporidium-attributable deaths (regions combined). ~59,000 excess deaths occurred among Cryptosporidium-attributable diarrhea cases over expected if cases had been Cryptosporidium-negative., Conclusions: The enormous African/Asian Cryptosporidium disease burden warrants investments to develop vaccines, diagnostics and therapies.

Background: Diarrheal disease is the second leading cause of disease in children less than 5 y of age. Poor water, sanitation, and hygiene conditions are the primary routes of exposure and infection. Sanitation and hygiene interventions are estimated to generate a 36% and 48% reduction in diarrheal risk in young children, respectively. Little is known about whether the number of households sharing a sanitation facility affects a child's risk of diarrhea. The objective of this study was to describe sanitation and hygiene access across the Global Enteric Multicenter Study (GEMS) sites in Africa and South Asia and to assess sanitation and hygiene exposures, including shared sanitation access, as risk factors for moderate-to-severe diarrhea (MSD) in children less than 5 y of age., Methods/findings: The GEMS matched case-control study was conducted between December 1, 2007, and March 3, 2011, at seven sites in Basse, The Gambia; Nyanza Province, Kenya; Bamako, Mali; Manhiça, Mozambique; Mirzapur, Bangladesh; Kolkata, India; and Karachi, Pakistan. Data was collected for 8,592 case children aged <5 y old experiencing MSD and for 12,390 asymptomatic age, gender, and neighborhood-matched controls. An MSD case was defined as a child with a diarrheal illness <7 d duration comprising ≥3 loose stools in 24 h and ≥1 of the following: sunken eyes, skin tenting, dysentery, intravenous (IV) rehydration, or hospitalization. Site-specific conditional logistic regression models were used to explore the association between sanitation and hygiene exposures and MSD. Most households at six sites (>93%) had access to a sanitation facility, while 70% of households in rural Kenya had access to a facility. Practicing open defecation was a risk factor for MSD in children <5 y old in Kenya. Sharing sanitation facilities with 1-2 or ≥3 other households was a statistically significant risk factor for MSD in Kenya, Mali, Mozambique, and Pakistan. Among those with a designated handwashing area near the home, soap or ash were more frequently observed at control households and were significantly protective against MSD in Mozambique and India., Conclusions: This study suggests that sharing a sanitation facility with just one to two other households can increase the risk of MSD in young children, compared to using a private facility. Interventions aimed at increasing access to private household sanitation facilities may reduce the burden of MSD in children. These findings support the current World Health Organization/ United Nations Children's Emergency Fund (UNICEF) system that categorizes shared sanitation as unimproved.

Molecular identification of the invasion plasmid antigen-H (ipaH) gene has been established as a useful detection mechanism for Shigella spp. The Global Enteric Multicenter Study (GEMS) identified the etiology and burden of moderate-to-severe diarrhea (MSD) in sub-Saharan Africa and south Asia using a case-control study and traditional culture techniques. Here, we used quantitative polymerase chain reaction (qPCR) to identify Shigella spp. in 2,611 stool specimens from GEMS and compared these results to those using culture. Demographic and nutritional characteristics were assessed as possible risk factors. The qPCR identified more cases of shigellosis than culture; however, the distribution of demographic characteristics was similar by both methods. In regression models adjusting for Shigella quantity, age, and site, children who were exclusively breast-fed had significantly lower odds of MSD compared with children who were not breast-fed (odds ratio [OR] = 0.47, 95% confidence interval (CI) = 0.28-0.81). The association between Shigella quantity and MSD increased with age, with a peak in children of 24-35 months of age (OR = 8.2, 95% CI = 4.3-15.7) and the relationship between Shigella quantity and disease was greatest in Bangladesh (OR = 13.2, 95% CI = 7.3-23.8). This study found that qPCR identified more cases of Shigella and age, site, and breast-feeding status were significant risk factors for MSD., (© The American Society of Tropical Medicine and Hygiene.)

Background: Infectious diarrhea leads to significant mortality in children, with 40 % of these deaths occurring in Africa. Classic human astroviruses are a well-established etiology of diarrhea. In recent years, seven novel astroviruses have been discovered (MLB1, MLB2, MLB3, VA1/HMO-C, VA2/HMO-B, VA3/HMO-A, VA4); however, there have been few studies on their prevalence or potential association with diarrhea., Methods: To investigate the prevalence and diversity of these classic and recently described astroviruses in a pediatric population, a case-control study was performed. Nine hundred and forty nine stools were previously collected from cases of moderate-to-severe diarrhea and matched controls of patients less than 5 years of age in Kenya and The Gambia. RT-PCR screening was performed using pan-astrovirus primers., Results: Astroviruses were present in 9.9 % of all stool samples. MLB3 was the most common astrovirus with a prevalence of 2.6 %. Two subtypes of MLB3 were detected that varied based on location in Africa. In this case-control study, Astrovirus MLB1 was associated with diarrhea in Kenya, whereas Astrovirus MLB3 was associated with the control state in The Gambia. Classic human astrovirus was not associated with diarrhea in this study. Unexpectedly, astroviruses with high similarity to Canine Astrovirus and Avian Nephritis Virus 1 and 2 were also found in one case of diarrhea and two control stools respectively., Conclusions: Astroviruses including novel MLB- and VA-clade members are commonly found in pediatric stools in Kenya and The Gambia. The most recently discovered astrovirus, MLB3, was the most prevalent and was found more commonly in control stools in The Gambia, while astrovirus MLB1 was associated with diarrhea in Kenya. Furthermore, a distinct subtype of MLB3 was noted, as well as 3 unanticipated avian or canine astroviruses in the human stool samples. As a result of a broadly reactive PCR screen for astroviruses, new insight was gained regarding the epidemiology of astroviruses in Africa, where a large proportion of diarrheal morbidity and mortality occur.

The World Health Organization (WHO) guidelines for diagnosis of pneumonia are based on the history of cough or difficult breathing and age-adjusted respiration rates. Metabolic acidosis associated with dehydrating diarrhoea also influences the respiration rate. Two hundred and four children, aged 2 to 59 months, with dehydrating diarrhoea and a history of cough and/or fast breathing, were enrolled in a prospective study. Pneumonia diagnoses were made on enrollment and again 6 hours post-enrollment (after initial rehydration), using the WHO guidelines. These were compared with investigators' clinical diagnosis based on history and findings of physical examination and a chest x-ray at the same time points. Using the WHO guidelines, 149/152 (98%) infants in the 2-11 months age-group and 38/40 (95%) children in the 12-59 months age-group were diagnosed to have pneumonia on enrollment, which dropped to 107 (70%) and 30 (75%) respectively at 6 hours post-enrollment. The specificity of the WHO guidelines for diagnosis of pneumonia was very low (6.9%) at enrollment but increased to 65.5% at 6 hours post-enrollment, after initial rehydration. The specificity of the WHO guidelines for diagnosis of pneumonia in young children is significantly reduced in dehydrating diarrhoea. For young children with dehydrating diarrhoea, rehydration, clinical and radiological assessments are useful in identifying those with true pneumonia.

Cultivation-based assays combined with PCR or enzyme-linked immunosorbent assay (ELISA)-based methods for finding virulence factors are standard methods for detecting bacterial pathogens in stools; however, with emerging molecular technologies, new methods have become available. The aim of this study was to compare four distinct detection technologies for the identification of pathogens in stools from children under 5 years of age in The Gambia, Mali, Kenya, and Bangladesh. The children were identified, using currently accepted clinical protocols, as either controls or cases with moderate to severe diarrhea. A total of 3,610 stool samples were tested by established clinical culture techniques: 3,179 DNA samples by the Universal Biosensor assay (Ibis Biosciences, Inc.), 1,466 DNA samples by the GoldenGate assay (Illumina), and 1,006 DNA samples by sequencing of 16S rRNA genes. Each method detected different proportions of samples testing positive for each of seven enteric pathogens, enteroaggregative Escherichia coli (EAEC), enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), Shigella spp., Campylobacter jejuni, Salmonella enterica, and Aeromonas spp. The comparisons among detection methods included the frequency of positive stool samples and kappa values for making pairwise comparisons. Overall, the standard culture methods detected Shigella spp., EPEC, ETEC, and EAEC in smaller proportions of the samples than either of the methods based on detection of the virulence genes from DNA in whole stools. The GoldenGate method revealed the greatest agreement with the other methods. The agreement among methods was higher in cases than in controls. The new molecular technologies have a high potential for highly sensitive identification of bacterial diarrheal pathogens.

Background: Diarrhoeal diseases cause illness and death among children younger than 5 years in low-income countries. We designed the Global Enteric Multicenter Study (GEMS) to identify the aetiology and population-based burden of paediatric diarrhoeal disease in sub-Saharan Africa and south Asia., Methods: The GEMS is a 3-year, prospective, age-stratified, matched case-control study of moderate-to-severe diarrhoea in children aged 0-59 months residing in censused populations at four sites in Africa and three in Asia. We recruited children with moderate-to-severe diarrhoea seeking care at health centres along with one to three randomly selected matched community control children without diarrhoea. From patients with moderate-to-severe diarrhoea and controls, we obtained clinical and epidemiological data, anthropometric measurements, and a faecal sample to identify enteropathogens at enrolment; one follow-up home visit was made about 60 days later to ascertain vital status, clinical outcome, and interval growth., Findings: We enrolled 9439 children with moderate-to-severe diarrhoea and 13,129 control children without diarrhoea. By analysing adjusted population attributable fractions, most attributable cases of moderate-to-severe diarrhoea were due to four pathogens: rotavirus, Cryptosporidium, enterotoxigenic Escherichia coli producing heat-stable toxin (ST-ETEC; with or without co-expression of heat-labile enterotoxin), and Shigella. Other pathogens were important in selected sites (eg, Aeromonas, Vibrio cholerae O1, Campylobacter jejuni). Odds of dying during follow-up were 8·5-fold higher in patients with moderate-to-severe diarrhoea than in controls (odd ratio 8·5, 95% CI 5·8-12·5, p<0·0001); most deaths (167 [87·9%]) occurred during the first 2 years of life. Pathogens associated with increased risk of case death were ST-ETEC (hazard ratio [HR] 1·9; 0·99-3·5) and typical enteropathogenic E coli (HR 2·6; 1·6-4·1) in infants aged 0-11 months, and Cryptosporidium (HR 2·3; 1·3-4·3) in toddlers aged 12-23 months., Interpretation: Interventions targeting five pathogens (rotavirus, Shigella, ST-ETEC, Cryptosporidium, typical enteropathogenic E coli) can substantially reduce the burden of moderate-to-severe diarrhoea. New methods and accelerated implementation of existing interventions (rotavirus vaccine and zinc) are needed to prevent disease and improve outcomes., Funding: The Bill & Melinda Gates Foundation., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: Diarrhea is a leading cause of illness and death among children aged <5 years in developing countries. This paper describes the clinical and epidemiological methods used to conduct the Global Enteric Multicenter Study (GEMS), a 3-year, prospective, age-stratified, case/control study to estimate the population-based burden, microbiologic etiology, and adverse clinical consequences of acute moderate-to-severe diarrhea (MSD) among a censused population of children aged 0-59 months seeking care at health centers in sub-Saharan Africa and South Asia., Methods: GEMS was conducted at 7 field sites, each serving a population whose demography and healthcare utilization practices for childhood diarrhea were documented. We aimed to enroll 220 MSD cases per year from selected health centers serving each site in each of 3 age strata (0-11, 12-23, and 24-59 months), along with 1-3 matched community controls. Cases and controls supplied clinical, epidemiologic, and anthropometric data at enrollment and again approximately 60 days later, and provided enrollment stool specimens for identification and characterization of potential diarrheal pathogens. Verbal autopsy was performed if a child died. Analytic strategies will calculate the fraction of MSD attributable to each pathogen and the incidence, financial costs, nutritional consequences, and case fatality overall and by pathogen., Conclusions: When completed, GEMS will provide estimates of the incidence, etiology, and outcomes of MSD among infants and young children in sub-Saharan Africa and South Asia. This information can guide development and implementation of public health interventions to diminish morbidity and mortality from diarrheal diseases.

Beyond the morbidity and mortality burden of childhood diarrhea in sub-Saharan African are significant economic costs to affected households. Using survey data from 3 of the 4 sites in sub-Saharan Africa (Gambia, Kenya, Mali) participating in the Global Enteric Multicenter Study (GEMS), we estimated the direct medical, direct nonmedical, and indirect (productivity losses) costs borne by households due to diarrhea in young children. Mean cost per episode was $2.63 in Gambia, $6.24 in Kenya, and $4.11 in Mali. Direct medical costs accounted for less than half of these costs. Mean costs understate the distribution of costs, with 10% of cases exceeding $6.50, $11.05, and $13.84 in Gambia, Kenya, and Mali. In all countries there was a trend toward lower costs among poorer households and in 2 of the countries for diarrheal illness affecting girls. For poor children and girls, this may reflect reduced household investment in care, which may result in increased risks of mortality.

Background: Efficacy of high-dose vitamin A (VA) in children suffering from severe acute malnutrition (SAM) has recently been questioned. This study compared the efficacy of a single high-dose (200,000 IU) in addition to daily low-dose (5000 IU) VA in the management of children suffering from SAM with diarrhea and/or acute lower respiratory tract infection (ALRI)., Methods: In a randomized, double-blind, controlled clinical trial in icddr,b, Bangladesh during 2005-07, children aged 6-59 months with weight-for-height <-3 Z-score and/or bipedal edema (SAM) received either a high-dose VA or placebo on admission day. Both the groups received 5,000 IU/day VA in a multivitamins drop for 15 days and other standard treatment which is similar to WHO guidelines., Results: A total 260 children (130 in each group) were enrolled. All had diarrhea, 54% had concomitant ALRI, 50% had edema, 48.5% were girl with a mean±SD age of 16±10 months. None had clinical signs of VA deficiency. Mean±SD baseline serum retinol was 13.15±9.28 µg/dl, retinol binding protein was 1.27±0.95 mg/dl, and pre-albumin was 7.97±3.96 mg/dl. Median (inter quartile range) of C-reactive protein was 7.8 (2.1, 22.2) mg/L. Children of the two groups did not differ in any baseline characteristic. Over the 15 days treatment period resolution of diarrhea, ALRI, edema, anthropometric changes, and biochemical indicators of VA were similar between the groups. The high-dose VA supplementation in children with SAM did not show any adverse event., Conclusions: Efficacy of daily low-dose VA compared to an additional single high-dose was not observed to be better in the management of children suffering from SAM with other acute illnesses. A single high-dose VA may be given especially where the children with SAM may leave the hospital/treatment center early., Trial Registration: ClinicalTrials.gov NCT00388921.

In this study, we have analysed the epidemiological significance of the concurrent infections caused by Vibrio cholerae and intestinal parasites among different age groups of hospitalized diarrhoeal patients in Kolkata. A total of 3556 stool samples collected during 1996-2004 were screened for vibrios and parasites. The seasonality of V. cholerae and parasitic infections were studied in detail. The detection rates for Ascaris lumbricoides and Giardia lamblia infection were more than for the hookworm, Trichuris trichiura and Entamoeba histolytica. V. cholerae O1 was identified as the predominant serogroup among diarrhoeal patients. The highest rates for V. cholerae infection were in the 2-5 years age group and combined infection of V. cholerae and parasites was recorded among children aged between 2 and 10 years.

This study was undertaken to measure the impact of periodic deworming with albendazole on growth status and incidence of diarrhoea in children aged 2-5 years in an urban setting in India and to assess the feasibility of local health workers implementing the procedures involved. This was a double-blind, placebo-controlled, randomized, community-based intervention trial with 702 children randomly allocated to receive either albendazole or placebo. The two study groups received two doses of albendazole (400 mg) or placebo six months apart. Mean weight increased significantly in the albendazole group compared to the control group at three months, six months and nine months following treatment (P<0.01, P<0.01 and P<0.001 respectively). The albendazole group also experienced fewer episodes of diarrhoea than their control counterparts (relative risk 1.3, 95% CI 1.07-1.53) with a 28% reduction. The health workers administered the correct dosage satisfactorily and there were no adverse effects. Thus, periodic mass deworming with albendazole would seem to be a safe and effective method that could be adopted at the community level or as an integral part of school health services and could be expected to improve growth and reduce the incidence of diarrhoea in children.

The prevalence of Salmonella enterica serotypes, antimicrobial susceptibility, and phage typing of serovers were studied. Clinical presentations of the infected cases were also examined. The study was carried out during August 1993-September 1996 in and around Calcutta, India. In total, 1,025 faecal samples from hospitalized diarrhoeal children were screened for enteropathogens. Four S. enterica serotypes were identified in 157 (15.3%) cases as a single pathogen. S. enterica serotype Typhimurium was detected in 110 (70%) cases. S. Seftenberg, S. Infantis, and S. Virchow were detected in 28 (17.8%), 14 (8.9%), and 5 (3.2%) cases respectively. S. Typhimurium was isolated from 11 (3.2%) non-diarrhoeal control children. All of these children had acute watery diarrhoea, and 5% of them had severe dehydration, 40% had some dehydration, and 55% had no dehydration. Vomiting, fever, and diffused pain in abdomen were the associated presentations of these children. Most (95%) of them recovered with oral rehydration therapy only and without any antibiotics. In-vitro susceptibility testing showed that 120 of the 121 S. Typhimurium strains isolated from cases and controls were resistant to the commonly-used drugs. Thirteen of the 121 strains were phage-typeable and belonged to the phage type 193. However, no clinical or epidemiological significance could be established with these typeable strains. The findings of the study indicate that diarrhoeagenic Salmonella is one of the major pathogens causing diarrhoeal diseases in eastern India.

A study was carried out in 3 villages near Calcutta, India, having a population of 5464, between August 1992 and December 1994. A cohort of rural children below 4 years of age was prospectively observed to determine the clinico-epidemiological aspects of mucoid diarrhoea and examine propensity to invasiveness. Overall, the incidence of diarrhoea was 1.7 episodes/child/year, and that of mucoid and bloody dysentery was 0.8 and 0.2 episodes/child/year, respectively. Children aged 6-11 months had a higher incidence of mucoid diarrhoea (1.3 episodes/child/year) and the peak season occurred in June and July. Multivariate analysis using logistic regression showed that mucoid diarrhoea and bloody dysentery were closely similar in both clinical and laboratory findings, including raised faecal leucocyte count (> 10/high power microscope field [hpf]). However, abdominal pain occurred more frequently in bloody dysentery than in mucoid diarrhoea. Faecal leucocyte count (> 10/hpf) can therefore be used as an indicator for invasiveness of mucoid diarrhoea at the community level.