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To evaluate how breakthrough rotavirus disease contributes to transmission, we examined the impact of rotavirus vaccination on fecal shedding and duration of illness. We used multivariable linear regression to analyze rotavirus quantity by RT-qPCR and duration among 184 episodes of rotavirus diarrhea positive by ELISA in the PROVIDE study. Vaccinated children had less fecal viral shedding compared to unvaccinated children (mean difference = -0.59 log copies per gram of stool; 95% confidence interval [CI], -.99 to -.19). Duration of illness was on average 0.47 days (95% CI, -.23 to 1.17 days) shorter among vaccinated children. Rotarix vaccination reduces shedding burden among breakthrough cases of rotavirus gastroenteritis. Clinical Trials Registration . NCT01375647., Competing Interests: Potential conflicts of interest. B. Lopman reports personal fees outside the submitted work from Epidemiologic Research Methods, LLC and Hillevax, Inc. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Background: An incomplete understanding of preterm birth is especially concerning for low-middle income countries, where preterm birth has poorer prognoses. While systemic proinflammatory processes are a reportedly normal component of gestation, excessive inflammation has been demonstrated as a risk factor for preterm birth. There is minimal research on the impact of excessive maternal inflammation in the first trimester on the risk of preterm birth in low-middle income countries specifically., Methods: Pregnant women were enrolled at the rural Bangladesh site of the National Institute of Child Health Global Network Maternal Newborn Health Registry. Serum samples were collected to measure concentrations of the inflammatory markers C-reactive protein (CRP) and Alpha-1-acid glycoprotein (AGP), and stool samples were collected and analyzed for enteropathogens. We examined associations of maternal markers in the first-trimester with preterm birth using logistic regression models. CRP and AGP were primarily modeled with a composite inflammation predictor., Results: Out of 376 singleton births analyzed, 12.5% were preterm. First trimester inflammation was observed in 58.8% of all births, and was significantly associated with increased odds of preterm birth (adjusted odds ratio [aOR] = 2.23; 95% confidence interval [CI]: 1.03, 5.16), independent of anemia. Maternal vitamin B12 insufficiency (aOR = 3.33; 95% CI: 1.29, 8.21) and maternal anemia (aOR = 2.56; 95% CI: 1.26, 5.17) were also associated with higher odds of preterm birth. Atypical enteropathogenic E. coli detection showed a significant association with elevated AGP levels and was significantly associated with preterm birth (odds ratio [OR] = 2.36; 95% CI: 1.21, 4.57), but not associated with CRP., Conclusions: Inflammation, anemia, and vitamin B12 insufficiency in the first trimester were significantly associated with preterm birth in our cohort from rural Bangladesh. Inflammation and anemia were independent predictors of premature birth in this low-middle income setting where inflammation during gestation was widespread. Further research is needed to identify if infections such as enteropathogenic E. coli are a cause of inflammation in the first trimester, and if intervention for infection would decrease preterm birth., (© 2024. The Author(s).)

Throughout the COVID-19 pandemic, many dashboards were created to visualise clinical case incidence. Other dashboards have displayed SARS-CoV-2 sewage data, largely from countries with formal sewage networks. However, very few dashboards from low-income and lower-middle-income countries integrated both clinical and sewage data sets. We created a dashboard to track in real-time both COVID-19 clinical cases and the level of SARS-CoV-2 virus in sewage in Dhaka, Bangladesh. The development of this dashboard was a collaborative iterative process with Bangladesh public health stakeholders to include specific features to address their needs. The final dashboard product provides spatiotemporal visualisations of COVID-19 cases and SARS-CoV-2 viral load at 51 sewage collection sites in 21 wards in Dhaka since 24 March 2020. Our dashboard was updated weekly for the Bangladesh COVID-19 national task force to provide supplemental data for public health stakeholders making public policy decisions on mitigation efforts. Here, we highlight the importance of working closely with public health stakeholders to create a COVID-19 dashboard for public health impact. In the future, the dashboard can be expanded to track trends of other infectious diseases as sewage surveillance is increased for other pathogens., Competing Interests: Competing interests: MT, RH and IMB received funding for this study from the Bill and Melinda Gates Foundation (payments made to the respective institutions)., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.)

Background: Clinical surveillance for COVID-19 has typically been challenging in low-income and middle-income settings. From December, 2019, to December, 2021, we implemented environmental surveillance in a converging informal sewage network in Dhaka, Bangladesh, to investigate SARS-CoV-2 transmission across different income levels of the city compared with clinical surveillance., Methods: All sewage lines were mapped, and sites were selected with estimated catchment populations of more than 1000 individuals. We analysed 2073 sewage samples, collected weekly from 37 sites, and 648 days of case data from eight wards with varying socioeconomic statuses. We assessed the correlations between the viral load in sewage samples and clinical cases., Findings: SARS-CoV-2 was consistently detected across all wards (low, middle, and high income) despite large differences in reported clinical cases and periods of no cases. The majority of COVID-19 cases (26 256 [55·1%] of 47 683) were reported from Ward 19, a high-income area with high levels of clinical testing (123 times the number of tests per 100 000 individuals compared with Ward 9 [middle-income] in November, 2020, and 70 times the number of tests per 100 000 individuals compared with Ward 5 [low-income] in November, 2021), despite containing only 19·4% of the study population (142 413 of 734 755 individuals). Conversely, a similar quantity of SARS-CoV-2 was detected in sewage across different income levels (median difference in high-income vs low-income areas: 0·23 log 10 viral copies + 1). The correlation between the mean sewage viral load (log 10 viral copies + 1) and the log 10 clinical cases increased with time (r = 0·90 in July-December, 2021 and r=0·59 in July-December, 2020). Before major waves of infection, viral load quantity in sewage samples increased 1-2 weeks before the clinical cases., Interpretation: This study demonstrates the utility and importance of environmental surveillance for SARS-CoV-2 in a lower-middle-income country. We show that environmental surveillance provides an early warning of increases in transmission and reveals evidence of persistent circulation in poorer areas where access to clinical testing is limited., Funding: Bill & Melinda Gates Foundation., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2023 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 illness is a leading cause of antibiotic use for children in low- and middle-income countries. Determination of diarrhea etiology at the point-of-care without reliance on laboratory testing has the potential to reduce inappropriate antibiotic use., Methods: This prospective observational study aimed to develop and externally validate the accuracy of a mobile software application ('App') for the prediction of viral-only etiology of acute diarrhea in children 0-59 months in Bangladesh and Mali. The App used a previously derived and internally validated model consisting of patient-specific ('present patient') clinical variables (age, blood in stool, vomiting, breastfeeding status, and mid-upper arm circumference) as well as location-specific viral diarrhea seasonality curves. The performance of additional models using the 'present patient' data combined with other external data sources including location-specific climate, data, recent patient data, and historical population-based prevalence were also evaluated in secondary analysis. Diarrhea etiology was determined with TaqMan Array Card using episode-specific attributable fraction (AFe) >0.5., Results: Of 302 children with acute diarrhea enrolled, 199 had etiologies above the AFe threshold. Viral-only pathogens were detected in 22% of patients in Mali and 63% in Bangladesh. Rotavirus was the most common pathogen detected (16% Mali; 60% Bangladesh). The present patient+ viral seasonality model had an AUC of 0.754 (0.665-0.843) for the sites combined, with calibration-in-the-large α = -0.393 (-0.455--0.331) and calibration slope β = 1.287 (1.207-1.367). By site, the present patient+ recent patient model performed best in Mali with an AUC of 0.783 (0.705-0.86); the present patient+ viral seasonality model performed best in Bangladesh with AUC 0.710 (0.595-0.825)., Conclusions: The App accurately identified children with high likelihood of viral-only diarrhea etiology. Further studies to evaluate the App's potential use in diagnostic and antimicrobial stewardship are underway., Funding: Funding for this study was provided through grants from the Bill and Melinda GatesFoundation (OPP1198876) and the National Institute of Allergy and Infectious Diseases (R01AI135114). Several investigators were also partially supported by a grant from the National Institute of Diabetes and Digestive and Kidney Diseases (R01DK116163). This investigation was also supported by the University of Utah Population Health Research (PHR) Foundation, with funding in part from the National Center for Advancing Translational Sciences of the National Institutes of Health under Award Number UL1TR002538. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The funders had no role in the study design, data collection, data analysis, interpretation of data, or in the writing or decision to submit the manuscript for publication., Competing Interests: SG received consultancy fees from the University of Utah, in relation to project "Development of clinical decision tools for management of diarrhea of children in high and low resource settings" (R01AI135114, PI: Leung), and from Department of Defense Naval Medical Logistics Command, for the Austere Environments Consortium for Enhanced Sepsis Outcomes: An Observational Study of Sepsis (N62645-14-2-0001). The author has no other competing interests to declare, EN is associated with a patent on data collection components in the 'Outbreak Responder' (Patent Publication Number 2020/0082921), of which the original 'Rehydration Calculator' was a component. These components are not included in the software referenced and published herein. Has no financial interest in the 'Rehydration Calculator' herein or the original 'Outbreak Responder' software, SN, AK, BB, MG, HB, JH, MT, JP, KK, RH, SS, NA, DL No competing interests declared, DN received travel funding for training and monitoring data collection in Mali. The author has no other competing interests to declare, AL received consultancy fees from the University of Utah, in relation to project "Development of clinical decision tools for management of diarrhea of children in high and low resource settings" (R01AI135114, PI: Leung). The author has no other competing interests to declare, (© 2022, Garbern et al.)

Introduction: Small intestine bacterial overgrowth (SIBO) is common in children from low-income countries and has been cross-sectionally associated with growth stunting. We sought to determine whether SIBO was associated with poor growth and neurodevelopmental in a longitudinal analysis., Methods: We measured SIBO by glucose hydrogen breath test (GHBT) at 18, 52, 78, and 104 weeks of life in a prospective longitudinal birth cohort of Bangladeshi children. Sociodemographic information and measures of enteric inflammation were analyzed as covariates. Diarrheal samples were tested for enteropathogens using polymerase chain reaction. Regression models were created using standardized mean GHBT area under the H2 curve (AUC) to determine associations with linear growth and cognitive, language, and motor scores on the Bayley-III Scales of Infant and Toddler Development at 2 years. We also investigated associations between GHBT AUC and enteropathogen exposure., Results: A 1-ppm increase in standardized mean GHBT AUC was associated with a 0.01-SD decrease in length-for-age Z score (P = 0.03) and a 0.11-point decrease in Bayley language score (P = 0.05) at 2 years of age in adjusted analysis. Enteroaggregative Escherichia coli, Enteropathogenic Escherichia coli, Giardia, and Enterocytozoon bieneusi were associated with increased GHBT AUC, whereas Clostridium difficile, norovirus GI, sapovirus, rotavirus, and Cryptosporidium were associated with decreased GHBT AUC. None were consistent across all 4 time points., Discussion: SIBO in the first 2 years of life is associated with growth stunting and decreased language ability in Bangladeshi infants and may represent a modifiable risk factor in poor growth and neurodevelopment in low-income countries., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of The American College of Gastroenterology.)

Since the global withdrawal of Sabin 2 oral poliovirus vaccine (OPV) from routine immunization, the Global Polio Eradication Initiative (GPEI) has reported multiple circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreaks. Here, we generated an agent-based, mechanistic model designed to assess OPV-related vaccine virus transmission risk in populations with heterogeneous immunity, demography, and social mixing patterns. To showcase the utility of our model, we present a simulation of mOPV2-related Sabin 2 transmission in rural Matlab, Bangladesh based on stool samples collected from infants and their household contacts during an mOPV2 clinical trial. Sabin 2 transmission following the mOPV2 clinical trial was replicated by specifying multiple, heterogeneous contact rates based on household and community membership. Once calibrated, the model generated Matlab-specific insights regarding poliovirus transmission following an accidental point importation or mass vaccination event. We also show that assuming homogeneous contact rates (mass action), as is common of poliovirus forecast models, does not accurately represent the clinical trial and risks overestimating forecasted poliovirus outbreak probability. Our study identifies household and community structure as an important source of transmission heterogeneity when assessing OPV-related transmission risk and provides a calibratable framework for expanding these analyses to other populations. Trial Registration: ClinicalTrials.gov This trial is registered with clinicaltrials.gov, NCT02477046., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: AB is employed by the Bill and Melinda Gates Foundation. He was involved in the study design of the original clinical study. He was not involved in the modeling paper portion of the study. All other authors do not have any competing interests.

Background: Diarrhea remains a major public health problem and characterization of its etiology is needed to prioritize interventions. However, most data are from single-site studies of children. We tested samples from participants of any age from 11 geographically diverse hospitals in Bangladesh to describe pathogen-specific burdens of diarrhea., Methods: We utilized 2 existing diarrhea surveillance systems: a Nationwide network at 10 sentinel hospitals and at the icddr,b hospital. We tested stools from enrolled participants and nondiarrheal controls for enteropathogens using quantitative polymerase chain reaction and calculated pathogen-specific attributable fractions (AFs) of diarrhea., Results: We analyzed 5516 patients with diarrhea and 735 controls. Overall, rotavirus had the highest attributable burden of diarrhea (Nationwide AF, 17.7%; 95% confidence interval [CI], 14.3-20.9%; icddr,b AF, 39.9%; 38.0-41.8%), followed by adenovirus 40/41 (Nationwide AF, 17.9%; 95% CI: 13.9-21.9%; icddr,b AF, 16.6%; 95% CI, 14.4-19.4%) and Vibrio cholerae (Nationwide AF, 10.2%; 95% CI, 9.1-11.3%; icddr,b AF, 13.3%; 95% CI: 11.9-15.1%). Rotavirus was the leading pathogen in children <5 years and was consistent across the sites (coefficient of variation = 56.3%). Adenovirus 40/41 was the second leading pathogen in both children and adults. Vibrio cholerae was the leading pathogen in individuals >5 years old, but was more geographically variable (coefficient of variation = 71.5%). Other attributable pathogens included astrovirus, norovirus, Shigella, Salmonella, ETEC, sapovirus, and typical EPEC., Conclusions: Rotavirus, adenovirus 40/41, and V. cholerae were the leading etiologies of infectious diarrhea requiring hospitalization in Bangladesh. Other pathogens were important in certain age groups or sites., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America.)

Background: Azithromycin is frequently used to treat shigellosis; however, clinical outcomes are uncertain., Methods: We performed an observational cohort study in Bangladesh of patients with invasive diarrhea treated empirically with azithromycin. Susceptibility testing was performed by broth microdilution and disk diffusion post hoc on all Shigella isolates and clinical response was correlated with in vitro susceptibility., Results: There were 149 Shigella culture-positive patients in the primary analysis. Infection with Shigella with decreased susceptibility to azithromycin was significantly associated with persistence of diarrhea at day 5 (31% vs 12%; relative risk [RR], 2.66; 95% confidence interval [CI], 1.34-5.28), culture positivity at day 5 or 6 (35% vs 5%; RR, 5.26; 95% CI, 1.84-14.85), and a higher rate of overnight hospitalization (58% vs 39%; RR, 1.49; 95% CI, 1.06-2.09). Shigella flexneri was more common than Shigella sonnei (58% vs 36%); however, S. sonnei constituted most of the isolates with decreased susceptibility to azithromycin (67%) and most of the multidrug-resistant strains (54%); thus, poor clinical outcomes were associated with S. sonnei. The current epidemiological cutoff for S. flexneri of ≥16 µg/mL to define decreased susceptibility to azithromycin was clinically predictive of poor outcome. Patients with S. sonnei and a low MIC (4 µg/mL) still had elevated rates of persistent diarrhea and culture positivity., Conclusions: This study documents worse clinical outcomes for S. flexneri with decreased susceptibility to azithromycin, as well as S. sonnei, and supports the utility of susceptibility testing and clinical breakpoints for azithromycin. S. sonnei is an emerging drug-resistant threat., Clinical Trials Registration: NCT03778125., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: Oral, live-attenuated rotavirus vaccines suffer from impaired immunogenicity and efficacy in low-income countries. Increasing the inoculum of vaccine might improve vaccine response, but this approach has been inadequately explored in low-income countries., Methods: We performed a double-blind, parallel group, randomized controlled trial from June 2017 through June 2018 in the urban Mirpur slum of Dhaka, Bangladesh to compare vaccine take (primary outcome) among healthy infants randomized to receive either the standard dose or double the standard dose of oral Rotarix (GlaxoSmithKline) vaccine at 6 and 10 weeks of life. Infants with congenital malformations, birth or enrollment weight <2000 gm, known immunocompromising condition, enrollment in another vaccine trial, or other household member enrolled in the study were excluded. Infants were randomized using random permuted blocks. Vaccine take was defined as detection of post-vaccination fecal vaccine shedding by real-time reverse transcription polymerase chain reaction with sequence confirmation or plasma rotavirus-specific immunoglobulin A (RV-IgA) seroconversion 4 weeks following the second dose., Results: 220 infants were enrolled and randomized (110 per group). 97 standard-dose and 92 high-dose infants completed the study per-protocol. For the primary outcome, no significant difference was observed between groups: vaccine take occurred in 62 (67%) high-dose infants versus 69 (71%) standard-dose infants (RR 0.92, 95% CI 0.67-1.24). However, in post-hoc analysis, children with confirmed vaccine replication had significantly increased RV-IgA responses, independent of the intervention. No significant adverse events related to study participation were detected., Conclusions: Administration of double the standard dose of an oral, live-attenuated rotavirus vaccine (Rotarix) did not improve vaccine take among infants in urban Dhaka, Bangladesh. However, improved immunogenicity in children with vaccine replication irrespective of initial inoculum provides further evidence for the need to promote in-host replication and improved gut health to improve oral vaccine response in low-income settings. ClinicalTrials.gov: NCT02992197., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Cryptosporidium is a leading contributor to diarrheal morbidity and mortality in under-5 children worldwide. As there is no vaccine and no effective drug therapy in young children for this infection, preventing infection is critical. We undertook a pilot case-control study to define the extent of person-to-person transmission of cryptosporidiosis within an urban and a rural community in Bangladesh., Methods: We enrolled 48 case families with a Cryptosporidium-infected child aged 6-18 months. Controls were age- and sex-matched Cryptosporidium-negative children in 12 households. Children and household members were followed for 8 weeks with weekly illness survey and stool testing with quantitative polymerase chain reaction for Cryptosporidium., Results: In the 24 urban case families, the secondary attack rate was 35.8% (19/53) vs 0% (0/11) in controls (P = .018, χ2 test). In contrast, in the 24 rural case families, the secondary attack rate was 7.8% (5/64) vs 0% (0/21) in controls (P = .19, χ2 test). Genotyping by gp60 demonstrated infection with the same subspecies in 5 families, and evidence of transmission in 2. Serologic response to Cryptosporidium infection was associated with younger age, longer duration of infection, and Cryptosporidium hominis gp60&#95;IbA9G3R2 infection., Conclusions: In the urban site, the high rate of secondary infection and infection with the same subspecies within families suggests that person-to-person transmission is a major source of Cryptosporidium infection for young children living in this region. Molecular genotyping can be applied to determine transmission of Cryptosporidium in endemic regions. Further work is needed to understand the differences in parasite transmissibility and immunity to different genotypes., (© The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America.)

Background: Cryptosporidium is a major cause of childhood diarrhea. Current modes of cryptosporidiosis diagnosis involve procedures that are costly and require both a well-equipped laboratory and technical expertise. Therefore, a cost-effective, user-friendly, and rapid method for point-of-care detection of Cryptosporidium is desirable., Methods: A total of 832 diarrheal stool specimens collected from 200 children aged <2 years were tested by Giardia/Cryptosporidium QUIK CHEK, enzyme-linked immunosorbent assay (ELISA), and quantitative polymerase chain reaction (qPCR) to compare the performance of the individual techniques. We also tested for the presence of other diarrheal pathogens in qPCR-positive samples with a TaqMan Array Card (TAC) to assess whether Cryptosporidium was the sole causative agent for the diarrheal episodes., Results: Of 832 samples, 4.4% were found positive for Cryptosporidium by QUIK CHEK, 3.6% by ELISA, and 8.8% by qPCR. Using TAC-attributed Cryptosporidium diarrhea as the gold standard, the sensitivities of QUIK CHEK, ELISA, and qPCR were 92.3%, 71.8%, and 100%, respectively; the specificities were 97.1%, 94.3%, and 0%, respectively. Analysis of the qPCR-positive and QUIK CHEK-negative samples by TAC identified other enteropathogens as more likely than Cryptosporidium to be the causative agents of diarrhea., Conclusions: QUIK CHEK was more sensitive and specific than ELISA. While qPCR detected Cryptosporidium in more samples than QUIK CHEK, most of these were instances of qPCR detecting small quantities of Cryptosporidium DNA in a diarrheal episode caused by another enteropathogen. We concluded that QUIK CHEK was comparable in sensitivity and superior in specificity to qPCR for the diagnosis of Cryptosporidium diarrhea.

Childhood diarrhea in low-resource settings has been variably linked to linear growth shortfalls. However, the association between etiology-specific diarrhea and growth has not been comprehensively evaluated. We tested diarrheal stools collected from the Performance of Rotavirus and Oral Polio Vaccines in Developing Countries study from 2011 to 2013 in Dhaka, Bangladesh, by quantitative polymerase chain reaction for a broad range of enteropathogens to characterize diarrhea etiology and examine the association between etiology-specific diarrhea and linear growth and systemic inflammation. Pathogen-specific burdens of diarrhea were determined using attributable fractions. Linear regression was used to examine associations of pathogen-specific diarrhea with length-for-age z scores (LAZ) and serum C-reactive protein. There was no relationship between all-cause diarrhea and length at 12 months (change in 12-month LAZ per episode, -0.01, 95% confidence interval (CI): -0.06, 0.03). However, Cryptosporidium (change in 12-month LAZ per attributable episode, -0.23, 95% CI: -0.50, 0.03), Campylobacter jejuni/coli (change of -0.16, 95% CI: -0.32, -0.01), and Shigella/enteroinvasive Escherichia coli diarrhea (change of -0.12, 95% CI: -0.26, 0.03) were associated with linear growth deficits. Diarrhea attributable to C. jejuni/coli and Shigella/enteroinvasive E. coli were associated with elevated C-reactive protein. The association between diarrhea and linear growth appears to be pathogen-specific, reinforcing the need for pathogen-specific interventions.

Two new monoclonal antibody-based, sandwich enzyme immunoassays (EIAs) for fecal antigen detection of Campylobacter jejuni or Campylobacter coli were evaluated using diarrheal stool specimens from a cohort of children in Bangladesh. These children routinely harbor multiple enteric pathogens, often at levels that make it difficult to assign diarrheal symptoms to a causative agent. A panel of 158 PCR-positive specimens with a broad range of C. jejuni / C. coli DNA cycle threshold ( C T ) values was used to assess the ability of the two tests to detect C. jejuni / C. coli antigen amounts that varied widely. A panel of 100 C. jejuni / C. coli PCR-negative specimens was used to verify that the assays correctly identified specimens as negative when the sample contained other enteric pathogens. Further analysis was conducted on a subset of 46 specimens that contained particularly substantial amounts of C. jejuni / C. coli ( C T of ≤19.7) that previous studies have ascribed as "diarrhea-associated." The Quik Chek rapid EIA and the Chek enzyme-linked immunosorbent assays (ELISAs) had a sensitivity of 95.7% for these specimens (specificities, 97% and 96%, respectively), supporting the usefulness of the new Chek and Quik Chek assays in symptomatic presentations, where Campylobacter is the likely etiology., (Copyright © 2018 Schnee et al.)

Background: Lewis and secretor histo-blood group antigens (HBGAs) have been associated with decreased susceptibility to P[8] genotype rotavirus (RV) infections. Efficacy of vaccines containing attenuated P[8] strains is decreased in low-income countries. Host phenotype might impact vaccine efficacy (VE) by altering susceptibility to vaccination or RV diarrhea (RVD). We performed a substudy in a monovalent RV vaccine (RV1) efficacy trial in Bangladesh to determine the impact of Lewis and secretor status on risk of RVD and VE., Methods: In infants randomized to receive RV1 or no RV1 at 10 and 17 weeks with 1 year of complete active diarrheal surveillance, we performed Lewis and secretor phenotyping and genotyped the infecting strain of each episode of RVD., Results: A vaccine containing P[8] RV protected secretors and nonsecretors similarly. However, unvaccinated nonsecretors had a reduced risk of RVD (relative risk, 0.53 [95% confidence interval, .36-.79]) mediated by complete protection from P[4] but not P[8] RVs. This effect reduced VE in nonsecretors to 31.7%, compared to 56.2% among secretors, and decreased VE for the overall cohort., Conclusions: Host HBGA status may impact VE estimates by altering susceptibility to RV in unvaccinated children; future trials should therefore account for HBGA status., Clinical Trials Registration: NCT01375647.

Background: Early exposure to enteropathogens has been associated with malnutrition in children in low-resource settings. However, the contribution of individual enteropathogens remains poorly defined. Molecular diagnostics offer an increase in sensitivity for detecting enteropathogens but have not been comprehensively applied to studies of malnutrition. Objective: We sought to identify enteropathogens associated with malnutrition in Bangladesh. Design: Malnourished children [weight-for-age z score (WAZ) <-2] aged 6-23 mo in Dhaka, Bangladesh, and identified by active community surveillance were enrolled as cases, and normal-weight children (WAZ >-1) of the same age and from the same community were enrolled as controls. Stools were collected at enrollment and, for cases, after a 5-mo nutritional intervention. Enrollment and follow-up stools were tested by quantitative polymerase chain reaction for 32 enteropathogens with the use of a custom-developed TaqMan Array Card. Results: Enteropathogen testing was performed on 486 cases and 442 controls upon enrollment and 365 cases at follow-up. At enrollment, the detection of enteroaggregative Escherichia coli (OR: 1.39; 95% CI: 1.05, 1.83), Campylobacter spp. (OR: 1.46; 95% CI: 1.11, 1.91), heat-labile enterotoxin-producing E. coli (OR: 1.55; 95% CI: 1.04, 2.33), Shigella /enteroinvasive E. coli (OR: 1.65; 95% CI: 1.10, 2.46), norovirus genogroup I (OR: 1.66; 95% CI: 1.23, 2.25), and Giardia (OR: 1.73; 95% CI: 1.20, 2.49) were associated with malnourished cases, and the total burden of these pathogens remained associated with malnutrition after adjusting for sociodemographic factors. The number of these pathogens at follow-up was negatively associated with the change in WAZ during the intervention (-0.10 change in WAZ per pathogen detected; 95% CI: -0.14, -0.06), whereas the number at enrollment was positively associated with the change in WAZ (0.05 change in WAZ per pathogen detected; 95% CI: 0.00, 0.10). Conclusions: A subset of enteropathogens was associated with malnutrition in this setting. Broad interventions designed to reduce the burden of infection with these pathogens are needed. This trial was registered at clinicaltrials.gov as NCT02441426.

Oral vaccines appear less effective in children in the developing world. Proposed biologic reasons include concurrent enteric infections, malnutrition, breast milk interference, and environmental enteropathy (EE). Rigorous study design and careful data management are essential to begin to understand this complex problem while assuring research subject safety. Herein, we describe the methodology and lessons learned in the PROVIDE study (Dhaka, Bangladesh). A randomized clinical trial platform evaluated the efficacy of delayed-dose oral rotavirus vaccine as well as the benefit of an injectable polio vaccine replacing one dose of oral polio vaccine. This rigorous infrastructure supported the additional examination of hypotheses of vaccine underperformance. Primary and secondary efficacy and immunogenicity measures for rotavirus and polio vaccines were measured, as well as the impact of EE and additional exploratory variables. Methods for the enrollment and 2-year follow-up of a 700 child birth cohort are described, including core laboratory, safety, regulatory, and data management practices. Intense efforts to standardize clinical, laboratory, and data management procedures in a developing world setting provide clinical trials rigor to all outcomes. Although this study infrastructure requires extensive time and effort, it allows optimized safety and confidence in the validity of data gathered in complex, developing country settings., (© The American Society of Tropical Medicine and Hygiene.)

Amid polio eradication efforts, detection of oral polio vaccine (OPV) virus in stool samples can provide information about rates of mucosal immunity and allow estimation of the poliovirus reservoir. We developed a multiplex one-step quantitative reverse transcription-PCR (qRT-PCR) assay for detection of OPV Sabin strains 1, 2, and 3 directly in stool samples with an external control to normalize samples for viral quantity and compared its performance with that of viral culture. We applied the assay to samples from infants in Dhaka, Bangladesh, after the administration of trivalent OPV (tOPV) at weeks 14 and 52 of life (on days 0 [pre-OPV], +4, +11, +18, and +25 relative to vaccination). When 1,350 stool samples were tested, the sensitivity and specificity of the quantitative PCR (qPCR) assay were 89 and 91% compared with culture. A quantitative relationship between culture(+)/qPCR(+) and culture(-)/qPCR(+) stool samples was observed. The kinetics of shedding revealed by qPCR and culture were similar. qPCR quantitative cutoffs based on the day +11 or +18 stool samples could be used to identify the culture-positive shedders, as well as the long-duration or high-frequency shedders. Interestingly, qPCR revealed that a small minority (7%) of infants contributed the vast majority (93 to 100%) of the total estimated viral excretion across all subtypes at each time point. This qPCR assay for OPV can simply and quantitatively detect all three Sabin strains directly in stool samples to approximate shedding both qualitatively and quantitatively., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Campylobacter is a common bacterial enteropathogen that can be detected in stool by culture, enzyme immunoassay (EIA), or PCR. We compared culture for C. jejuni/C. coli, EIA (ProSpecT), and duplex PCR to distinguish Campylobacter jejuni/C. coli and non-jejuni/coli Campylobacter on 432 diarrheal and matched control stool samples from infants in a multisite longitudinal study of enteric infections in Tanzania, Bangladesh, and Peru. The sensitivity and specificity of culture were 8.5% and 97.6%, respectively, compared with the results of EIA and 8.7% and 98.0%, respectively, compared with the results of PCR for C. jejuni/C. coli. Most (71.6%) EIA-positive samples were positive by PCR for C. jejuni/C. coli, but 27.6% were positive for non-jejuni/coli Campylobacter species. Sequencing of 16S rRNA from 53 of these non-jejuni/coli Campylobacter samples showed that it most closely matched the 16S rRNA of C. hyointestinalis subsp. lawsonii (56%), C. troglodytis (33%), C. upsaliensis (7.7%), and C. jejuni/C. coli (2.6%). Campylobacter-negative stool spiked with each of the above-mentioned Campylobacter species revealed reactivity with EIA. PCR detection of Campylobacter species was strongly associated with diarrhea in Peru (odds ratio [OR] = 3.66, P < 0.001) but not in Tanzania (OR = 1.56, P = 0.24) or Bangladesh (OR = 1.13, P = 0.75). According to PCR, Campylobacter jejuni/C. coli infections represented less than half of all infections with Campylobacter species. In sum, in infants in developing country settings, the ProSpecT EIA and PCR for Campylobacter reveal extremely high rates of positivity. We propose the use of PCR because it retains high sensitivity, can ascertain burden, and can distinguish between Campylobacter infections at the species level.

Background: An estimated one-third of children younger than 5 years in low- and middle-income countries fail to meet their full developmental potential. The first year of life is a period of critical brain development and is also when most of the morbidity from infection is suffered. We aimed to determine if clinical and biological markers of inflammation in the first year of life predict cognitive, language, and motor outcomes in children living in an urban slum in Bangladesh., Methods: Children living in Dhaka, Bangladesh were observed from birth until 24 months of age. Febrile illness was used as a clinical marker of inflammation and elevated concentrations of inflammation-related cytokines (IL-1β, IL-6, TNF-α, IL-4, IL-10) in sera collected from a subset of the cohort (N = 127) at 6 months of age were used as biomarkers of inflammation. Psychologists assessed cognitive, language, and motor development using a culturally adapted version of the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) at 12 (N = 398) and 24 months of age (N = 210). We tested for the ability of febrile illness and elevated cytokine levels to predict developmental outcomes, independent of known predictors of stunting, family income, and maternal education., Results: Every additional 10 days of fever was associated with a 1.9 decrease in language composite score and a 2.1 decrease in motor composite score (p = 0.005 and 0.0002, respectively). Elevated levels of the pro-inflammatory cytokines IL-1β (> 7.06 pg/mL) and IL-6 (> 10.52 pg/mL) were significantly associated with a 4.9 and 4.3 decrease in motor score, respectively. Conversely, an elevated level of the Th-2 cytokine IL-4 (> 0.70 pg/mL) was associated with a 3.6 increase in cognitive score (all p < 0.05)., Conclusions: Clinical and biological markers of inflammation in the first year of life were significantly associated with poor neurodevelopmental outcomes. Conversely, a Th2-like response was associated with a better outcome. These findings suggest that markers of inflammation could serve as prognostic indicators and potentially lead to immune-based therapies to prevent developmental delays in at-risk children.

Background: Diarrhea causes enormous morbidity and mortality in developing countries, yet the relative importance of multiple potential enteropathogens has been difficult to ascertain., Methods: We performed a longitudinal cohort study from birth to 1 year of age in 147 infants in Dhaka, Bangladesh. Using multiplex polymerase chain reaction, we analyzed 420 episodes of diarrhea and 1385 monthly surveillance stool specimens for 32 enteropathogen gene targets. For each infant we examined enteropathogen quantities over time to ascribe each positive target as a probable or less-likely contributor to diarrhea., Results: Multiple enteropathogens were detected by the first month of life. Diarrhea was associated with a state of overall pathogen excess (mean number of enteropathogen gene targets (± SE), 5.6 ± 0.1 vs 4.3 ± 0.1 in surveillance stool specimens; P < .05). After a longitudinal, quantitative approach was applied to filter out less-likely contributors, each diarrheal episode still had an average of 3.3 probable or dominant targets. Enteroaggregative Escherichia coli, Campylobacter, enteropathogenic E. coli, rotavirus, and Entamoeba histolytica were the most frequent probable contributors to diarrhea. Rotavirus was enriched in moderate to severe diarrheal episodes., Conclusions: In this community-based study diarrhea seemed to be a multipathogen event and a state of enteropathogen excess above a high carriage baseline.

Background: Entamoeba moshkovskii is prevalent in developing countries and morphologically indistinguishable from pathogenic Entamoeba histolytica and nonpathogenic Entamoeba dispar. It is not known if E. moshkovskii is pathogenic., Methods: Mice were intracecally challenged with the trophozoites of each Entamoeba spp. to test the ability to cause diarrhea, and infants in Bangladesh were prospectively observed to see if newly acquired E. moshkovskii infection was associated with diarrhea., Results: E. moshkovskii and E. histolytica caused diarrhea and weight loss in susceptible mice. E. dispar infected none of the mouse strains tested. In Mirpur, Dhaka, Bangladesh, E. moshkovskii, E. histolytica, and E. dispar were identified in 42 (2.95%), 66 (4.63%), and 5 (0.35%), respectively, of 1426 diarrheal episodes in 385 children followed prospectively from birth to one year of age. Diarrhea occurred temporally with acquisition of a new E. moshkovskii infection: in the 2 months preceding E. moshkvskii-associated diarrhea, 86% (36 of 42) of monthly surveillance stool samples were negative for E. moshkovskii., Conclusions: E. moshkovskii was found to be pathogenic in mice. In children, the acquisition of E. moshkovskii infection was associated with diarrhea. These data are consistent with E. moshkovskii causing disease, indicating that it is important to reexamine its pathogenicity.