Micro-heterogeneity of transmission shapes the submicroscopic malaria reservoir in coastal Tanzania.

Background: Asymptomatic malaria may be patent (visible by microscopy) and detectable by rapid malaria diagnostic tests (RDTs), or it may be submicroscopic and only detectable by polymerase chain reaction (PCR). Methods: To characterize the submicroscopic reservoir in an area of declining malaria transmission, asymptomatic persons >5 years of age in Bagamoyo District, Tanzania, were screened using RDT, microscopy, and PCR. We investigated the size of the submicroscopic reservoir across villages, determined factors associated with submicroscopic parasitemia, and assessed the natural history of submicroscopic malaria over four weeks. Results: Among 6,076 participants, Plasmodium falciparum prevalence by RDT, microscopy, and PCR was 9%, 9%, and 28%, respectively, with roughly two-thirds of PCR-positive individuals harboring submicroscopic infection. Adult status, female gender, dry season months, screened windows, and bednet use were associated with submicroscopic carriage. Among 15 villages encompassing 80% of participants, the proportion of submicroscopic carriers increased with decreasing village-level malaria prevalence. Over four weeks, 23% (61/266) of submicroscopic carriers became RDT-positive and were treated, with half exhibiting symptoms. This occurred more frequently in villages with higher malaria prevalence. Conclusions: Micro-heterogeneity in transmission impacts the size of the submicroscopic reservoir and the likelihood of submicroscopic carriers developing patent malaria in coastal Tanzania.

Plasmodium falciparum with pfhrp2/3 Deletion Not Detected in a 2018-2021 Malaria Longitudinal Cohort Study in Kinshasa Province, Democratic Republic of the Congo.

Histidine-rich protein 2- (HRP2-) based rapid diagnostic tests (RDTs) are widely used to detect Plasmodium falciparum in sub-Saharan Africa. Reports of parasites with pfhrp2 and/or pfhrp3 (pfhrp2/3) gene deletions in Africa raise concerns about the long-term viability of HRP2-based RDTs. We evaluated changes in pfhrp2/3 deletion prevalence over time using a 2018-2021 longitudinal study of 1,635 enrolled individuals in Kinshasa Province, Democratic Republic of the Congo (DRC). Samples collected during biannual household visits with ≥ 100 parasites/µL by quantitative real-time polymerase chain reaction were genotyped using a multiplex real-time PCR assay. Among 2,726 P. falciparum PCR-positive samples collected from 993 participants during the study period, 1,267 (46.5%) were genotyped. No pfhrp2/3 deletions or mixed pfhrp2/3-intact and -deleted infections were identified in our study. Pfhrp2/3-deleted parasites were not detected in Kinshasa Province; ongoing use of HRP2-based RDTs is appropriate.

Akkermansia muciniphila Associated with Improved Linear Growth among Young Children, Democratic Republic of the Congo.

To investigate the association between enteric pathogens, fecal microbes, and child growth, we conducted a prospective cohort study of 236 children <5 years of age in rural eastern Democratic Republic of the Congo. We analyzed baseline fecal specimens by quantitative PCR and measured child height and weight at baseline and growth at a 6-month follow-up. At baseline, 66% (156/236) of children had >3 pathogens in their feces. We observed larger increases in height-for-age-z-scores from baseline to the 6-month follow-up among children with Akkermansia muciniphila in their feces (coefficient 0.02 [95% CI 0.0001-0.04]; p = 0.04). Children with Cryptosporidium in their feces had larger declines in weight-for-height/length z-scores from baseline to the 6-month follow-up (coefficient -0.03 [95% CI -0.05 to -0.005]; p = 0.02). Our study showed high prevalence of enteric pathogens among this pediatric cohort and suggests A. muciniphila can potentially serve as a probiotic to improve child growth.

Association between breastfeeding, host genetic factors, and calicivirus gastroenteritis in a Nicaraguan birth cohort.

BACKGROUND: Norovirus and sapovirus are important causes of childhood acute gastroenteritis (AGE). Breastfeeding prevents AGE generally; however, it is unknown if breastfeeding prevents AGE caused specifically by norovirus and sapovirus. METHODS: We investigated the association between breastfeeding and norovirus or sapovirus AGE episodes in a birth cohort. Weekly data on breastfeeding and AGE episodes were captured during the first year of life. Stools were collected from children with AGE and tested by RT-qPCR for norovirus and sapovirus. Time-dependent Cox models estimated associations between weekly breastfeeding and time to first norovirus or sapovirus AGE. FINDINGS: From June 2017 to July 2018, 444 newborns were enrolled in the study. In the first year of life, 69 and 34 children experienced a norovirus and a sapovirus episode, respectively. Exclusive breastfeeding lasted a median of 2 weeks, and any breastfeeding lasted a median of 43 weeks. Breastfeeding in the last week did not prevent norovirus (HR: 1.09, 95% CI: 0.62, 1.92) or sapovirus (HR: 1.00, 95% CI: 0.82, 1.21) AGE in a given week, adjusting for household sanitation, consumption of high-risk foods, and mother's and child's histo-blood group phenotypes. Maternal secretor-positive phenotype was protective against norovirus AGE, whereas child's secretor-positive phenotype was a risk factor for norovirus AGE. INTERPRETATION: Exclusive breastfeeding in this population was short-lived, and no conclusions could be drawn about its potential to prevent norovirus or sapovirus AGE. Non-exclusive breastfeeding did not prevent norovirus or sapovirus AGE in the first year of life. However, maternal secretor-positive phenotype was associated with a reduced hazard of norovirus AGE.

Enteropathy Markers in Early Life Were Associated with Adipokine, Apolipoprotein, and Cytokine Profiles Consistent with an Adverse Cardiometabolic Disease Risk Profile Later in Childhood in a Peruvian Birth Cohort.

Metabolic syndrome is a cluster of risk factors for cardiovascular disease afflicting more than 1 billion people worldwide and is increasingly being identified in younger age groups and in socioeconomically disadvantaged settings in the global south. Enteropathogen exposure and environmental enteropathy in infancy may contribute to metabolic syndrome by disrupting the metabolic profile in a way that is detectable in cardiometabolic markers later in childhood. A total of 217 subjects previously enrolled in a birth cohort in Amazonian Peru were monitored annually from ages 2 to 5 years. A total of 197 blood samples collected in later childhood were analyzed for 37 cardiometabolic biomarkers, including adipokines, apolipoproteins, cytokines, which were matched to extant early-life markers of enteropathy ascertained between birth and 2 years. Multivariate and multivariable regression models were fitted to test for associations, adjusting for confounders. Fecal and urinary markers of intestinal permeability and inflammation (myeloperoxidase, lactulose, and mannitol) measured in infancy were associated with later serum concentrations of soluble CD40-ligand, a proinflammatory cytokine correlated with adverse metabolic outcomes. Fecal myeloperoxidase was also associated with later levels of omentin-1. Enteric protozoa exposure showed stronger associations with later cardiometabolic markers than viruses, bacteria, and overall diarrheal episodes. Early-life enteropathy markers were associated with altered adipokine, apolipoprotein, and cytokine profiles later in childhood consistent with an adverse cardiometabolic disease risk profile in this cohort. Markers of intestinal permeability and inflammation measured in urine (lactulose, mannitol) and stool (myeloperoxidase, protozoal infections) during infancy may predict metabolic syndrome in adulthood.

Low dietary diversity is associated with linear growth faltering and subsequent adverse child developmental outcomes in rural Democratic Republic of the Congo (REDUCE program).

The objective of this study was to investigate the association between dietary diversity, child growth and child developmental outcomes. This was a prospective cohort study. Developmental outcomes were assessed by communication, fine motor, gross motor, personal social, problem solving and combined developmental scores measured by the Extended Ages and Stages Questionnaire (EASQ) at a 6-month follow-up visit. Height and weight were measured at baseline and a 6-month follow-up. Baseline minimum dietary diversity (MDD) for children 6-23 months old was defined by consumption of five or more of the following food groups: (1) breast milk; (2) grains, roots and tubers; (3) legumes and nuts; (4) dairy products; (5) flesh foods; (6) eggs; (7) vitamin A-rich fruits and vegetables and (8) other fruits and vegetables. Participants were 117 children 6-23 months of age. Linear growth faltering was defined as a significant decline (p < 0.05) in length-for-age Z-scores (LAZ) between baseline and follow-up. Regression models were performed. The study was conducted in rural eastern Democratic Republic of the Congo (DRC). MDD was positively associated with change in LAZ (coefficient: 0.87 [95% confidence interval [CI]: 0.33, 1.40]), and a reduced odds of stunting (LAZ < -2) (odds ratio: 0.21 [95% CI: 0.07, 0.61]). MDD was also associated with a significantly higher combined EASQ-Z-scores (coefficient: 0.34 [95% CI: 0.003, 0.68], higher communication EASQ-Z-scores [0.50 {95% CI: 0.14, 0.85}], and higher personal social EASQ-Z-scores [0.46 {95% CI: 0.11, 0.82}]). This study provides further evidence demonstrating the need for interventions to improve dietary diversity among young children.

Water, Sanitation, and Hygiene and Nutritional Risk Factors for Acute Respiratory Illness in the Democratic Republic of the Congo: REDUCE Prospective Cohort Study.

The objective of this cohort study was to examine the prevalence of acute respiratory illness among children under 5 years of age and to identify water, sanitation, and hygiene (WASH) and nutritional risk factors. This prospective cohort study was conducted in Walungu Territory, South Kivu, and Democratic Republic of the Congo (DRC), and enrolled 512 participants. Spot checks of the household environment were conducted at baseline. Baseline minimum dietary diversity (MDD) was defined by consumption of five or more of the following food groups: 1) breast milk; 2) grains, roots, and tubers; 3) legumes and nuts; 4) dairy products; 5) flesh foods; 6) eggs; 7) vitamin A rich fruits and vegetables; and 8) other fruits and vegetables. Acute respiratory illness was defined as caregiver reported rapid breathing, difficulty breathing, lower chest wall in drawing, or coughing in the previous 2 weeks obtained at a 6-month follow-up based on the use of this definition in previous studies in Bangladesh and Kenya. A total of 58% of children had acute respiratory illness, 19% had soap present in the cooking area, and 4% in the defecation area, and 21% of children met MDD. A decreased odds of acute respiratory illness was associated with soap being present in the cooking area (odds ratio [OR]: 0.49, 95% confidence interval [CI]: 0.38-0.88) and MDD (OR: 0.62, 95% CI: 0.38-1.00). These findings highlight the need for interventions targeting hygiene and improved dietary diversity among rural DRC households to reduce the rate of respiratory illnesses in children under 5 years.

Diarrheal Disease Awareness Is Associated with Caregiver Handwashing with Soap in the Democratic Republic of the Congo (REDUCE Program).

Diarrhea is one of the leading causes of childhood illness and a major cause of infant and child mortality globally. In the Reducing Enteropathy, Undernutrition, and Contamination in the Environment (REDUCE) prospective cohort study, we investigated the association between diarrheal disease awareness and handwashing with soap among caregivers of children under 5 years of age. A total of 259 caregivers of children under 5 years of age in Walungu Territory, South Kivu, Democratic Republic of the Congo (DRC), were administered an open-ended questionnaire assessing awareness of diarrheal disease transmission and prevention, and key times to wash hands with soap. An overall diarrhea awareness score was developed based on the responses to these items. Five-hour structured observation of handwashing behaviors was conducted at the 6-month follow-up. Diarrheal disease awareness among caregivers was low. Only 32% of caregivers were able to correctly identify a method of diarrhea prevention. The median diarrhea awareness score was three out of 10 (SD: 1.7, range: 0-9). During structured observation, 9% of caregivers washed their hands with soap at a food-related event and 9% washed their hands with soap at a stool-related event. Higher diarrheal disease awareness was associated with an increased odds of handwashing with soap at food-related events (odds ratio: 1.40, 95% confidence interval: 1.03, 1.90). Our findings emphasize the need for targeted water, sanitation, and hygiene interventions to increase diarrhea awareness to facilitate handwashing with soap among caregivers of children under 5 years in rural DRC.

Permethrin-treated baby wraps for the prevention of malaria: results of a randomized controlled pilot study in rural Uganda.

BACKGROUND: Progress against malaria has stalled and may even be slipping backwards in high-burden countries. This is due to a range of factors including insecticide resistance and mosquito feeding behaviours that limit contact with widely-employed interventions including long-lasting insecticidal nets and indoor-residual spraying. Thus, further innovations in malaria control are urgently needed. METHODS: The pilot was a randomized, placebo-controlled pilot study of permethrin-treated baby wraps-known locally as lesus-in children 6-18 months of age at a single site in rural western Uganda. Fifty mother-infant pairs were assigned to permethrin-treated or untreated lesus in a 1:1 allocation. Participants and clinical staff were blinded to group assignments through use of sham treatment and re-treatment of lesus. Participants attended scheduled clinic visits every 2 weeks for a total 12 weeks. The primary outcome of interest was the safety of the intervention, assessed as changes in the frequency of use, rates of discontinuation, and incidence of adverse events, such as skin rash. Secondary outcomes included acceptability and feasibility of the intervention as measured through participant satisfaction and completion of study activities, respectively. RESULTS: Overall, rates of retention and participation were relatively high with 86.0% (43 of 50) of participants completing all scheduled visits, including 18 (75.0%) and 25 (96.2%) in the intervention and control arms respectively. By the conclusion of the 12-week follow-up period, one adverse event (0.35 events per 100 person-weeks, one-sided 95% CI 0.0-1.65) was reported. Satisfaction with the lesu was high in both groups. In each study arm, there were five incident RDT positive results, but the only PCR-positive results were observed in the control group (n = 2). CONCLUSIONS: Permethrin-treated baby wraps were well-tolerated and broadly acceptable. Adverse events were infrequent and mild. These findings support future trials seeking to determine the efficacy of treated wraps to prevent P. falciparum malaria infection in young children as a complementary tool to existing household-based interventions. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04102592, Registered 25 September 2019. Available at: https://clinicaltrials.gov/ct2/show/NCT04102592.

Fecal Contamination in Child Play Spaces and on Child Hands Are Associated with Subsequent Adverse Child Developmental Outcomes in Rural Democratic Republic of the Congo: REDUCE Prospective Cohort Study.

The objective of the Reducing Enteropathy, Undernutrition, and Contamination in the Environment (REDUCE) program is to identify exposure pathways to fecal pathogens that are significant contributors to morbidity among young children in the Democratic Republic of the Congo (DRC), and on developing and evaluating scalable interventions to reduce fecal contamination from these pathways. This prospective cohort study of 270 children under 5 years of age was conducted in rural South Kivu, DRC, to investigate the association between Escherichia coli in hand rinse, soil, food, object, surface, stored water, and water source samples and child developmental outcomes. Child developmental outcomes were assessed by communication, fine motor, gross motor, personal social, problem-solving, and combined scores measured by the Extended Ages and Stages Questionnaire (EASQ) at a 6-month follow-up. Children having E. coli present in the soil in their play spaces had significantly lower combined EASQ z scores (coefficient: -0.38 (95% CI: -0.73, -0.03)). E. coli on children's hands was associated with lower communication EASQ z scores (-0.37 (95% CI: -0.0.10, -0.01), and E. coli in stored drinking water was associated with lower gross motor EASQ z scores (-0.40 (95% CI: -0.68, -0.12). In the REDUCE cohort study, E. coli in child play spaces, on children's hands, and in stored drinking water was associated with lower developmental outcome scores (communication, gross motor, fine motor, and problem-solving skills). These results suggest the need for interventions to reduce fecal contamination in the household environment to protect the cognitive development of susceptible pediatric populations in rural DRC.

Linear Growth Faltering Is Associated with Subsequent Adverse Child Cognitive Developmental Outcomes in the Democratic Republic of the Congo (REDUCE Program).

Globally, 140 million children under 5 years of age are estimated to be stunted. Previous studies have found an association between stunting and poor cognitive outcomes. However, there is limited evidence of this association in sub-Saharan African settings, such as the Democratic Republic of the Congo (DRC). This prospective cohort study of 286 children under 5 years was conducted in rural DRC to investigate the association between diarrhea prevalence, child growth, and child cognitive developmental outcomes. Developmental outcomes were assessed by communication, fine motor, gross motor, personal social, problem-solving, and combined developmental scores measured by the Extended Ages and Stages Questionnaire (EASQ) at a 6-month follow-up visit. Height and weight were measured at baseline and a 6-month follow-up. Diarrhea prevalence was assessed through surveillance visits. Diarrhea prevalence was not associated with follow-up combined EASQ Z-scores at the 6-month follow-up (coefficient: -0.06 [95% CI: -0.29, 0.17]). Each additional standard deviation (SD) increase in height-for-age Z-scores from baseline to the 6-month follow-up increased combined EASQ Z-scores by 0.22 (95%: 0.14, -0.31) SDs. Each additional SD increase in weight-for-age Z-scores from baseline to the 6-month follow-up increased combined EASQ Z-scores by 0.21 (95%: 0.10, -0.32) SDs. Linear growth faltering and reduced weight gain were associated with reduced cognitive developmental outcomes among children residing in rural DRC. Interventions are urgently needed for this susceptible pediatric population to improve child growth and cognitive developmental outcomes.

Identifying psychosocial determinants of water, sanitation, and hygiene (WASH) behaviors for the development of evidence-based Baby WASH interventions (REDUCE program).

Diarrheal disease remains a leading cause of child mortality, globally. In the Democratic Republic of the Congo (DRC), each year there are an estimated 45 million episodes of diarrhea in children under five years of age. The Reducing Enteropathy, Diarrhea, Undernutrition, and Contamination in the Environment (REDUCE) program seeks to develop theory-driven, evidence-based approaches to reduce diarrheal diseases among young children. The REDUCE prospective cohort study in Walungu Territory in Eastern DRC took guidance from the risks, attitudes, norms, abilities, and self-regulation model, the integrated behavioral model for water, sanitation, and hygiene (WASH), and other behavior change theories to identify psychosocial factors associated with WASH behaviors. Psychosocial factors were measured among 417 caregivers at baseline and caregiver responses to child mouthing of dirty fomites and handwashing with soap was assessed by 5-hour structured observation at the 6-month follow-up. Caregivers who agreed that their child could become sick if they put dirt in their mouth (perceived susceptibility) and caregivers that agreed they could prevent their child from playing with dirty things outside (self-efficacy) were significantly more likely to stop their child from mouthing a dirty fomite. Higher perceived susceptibility, self-efficacy, and disgust, and lower dirty reactivity, were associated with higher handwashing with soap behaviors. This study took a theory-driven and evidence-based approach to identify psychosocial factors to target for intervention development. The findings from this study informed the development of the REDUCE Baby WASH Modules that have been delivered to over 1 million people in eastern DRC.

Formative research for the development of baby water, sanitation, and hygiene interventions for young children in the Democratic Republic of the Congo (REDUCE program).

BACKGROUND: Research exploring the unique exposure pathways to fecal pathogens for young children and innovative water, sanitation, and hygiene (WASH) interventions for susceptible pediatric populations is needed to reduce the burden of diarrheal diseases and stunting globally. The Reducing Enteropathy, Diarrhea, Undernutrition, and Contamination in the Environment (REDUCE) program seeks to 1) identify exposure pathways to fecal pathogens that are significant contributors to morbidity for young children in South Kivu, Democratic Republic of the Congo, and 2) develop and evaluate scalable interventions that reduce fecal contamination and exposure from these pathways. The formative research portion of the project sought to identify feasible and acceptable WASH interventions to modify behaviors found to be associated with diarrheal disease and impaired growth in our REDUCE cohort study. METHODS: Ninety-one semi-structured interviews, 6 focus group discussions, and a pilot study of 102 households were conducted during 24 months of formative research. Thirty-one interviews and six focus group discussions were conducted with caregivers, community health workers, and village leaders to explore existing WASH practices and to identify barriers and facilitators to WASH behaviors. Findings were organized using the Integrated Behavioral Model for Water, Sanitation and Hygiene to facilitate interpretation and identify determinants to Baby WASH behaviors in this setting. Care Group modules and enabling technology were developed based on exploratory findings and then revised during a two-part, iterative pilot study. Sixty interviews were conducted with participants in a pilot study of the REDUCE Baby WASH Care Group modules to learn about their experiences with the intervention. RESULTS: Six REDUCE Baby WASH Care Group modules were developed based on formative research findings and covered the following topics: 1) living with animals; 2) child mouthing of fomites and feces; 3) composting animal feces; 4) child feces disposal; 5) handwashing with soap; and 6) water treatment. CONCLUSION: This study took a theory-driven and evidence-based approach to formative research and the development of the REDUCE Baby WASH Care Group modules. Intervention design focused on interrupting the exposure routes for infants and young children to fecal pathogens in the environment and promoting low-cost, low-burden Baby WASH behavioral recommendations and enabling technology. These developed REDUCE Baby WASH Care Group modules are currently being rolled out to over 1,000,000 beneficiaries in Democratic Republic of the Congo.

Child Mouthing of Feces and Fomites and Animal Contact are Associated with Diarrhea and Impaired Growth Among Young Children in the Democratic Republic of the Congo: A Prospective Cohort Study (REDUCE Program).

OBJECTIVE: To identify exposure pathways to fecal pathogens that are significant contributors to diarrheal diseases and impaired growth in young children, and to evaluate scalable interventions to reduce fecal contamination from these pathways. STUDY DESIGN: Reducing Enteropathy, Undernutrition, and Contamination in the Environment (REDUCE) was a prospective cohort study of 370 children <5 years of age was conducted in Walungu Territory, South Kivu, Democratic Republic of the Congo. Child mouthing behaviors were assessed through caregiver reports and 5-hour structured observations. Caregiver reports of child contact with animals and child diarrhea were also obtained. Anthropometric measurements were collected at baseline and at a 6-month follow-up. RESULTS: Children observed putting soil in their mouth during structured observation at baseline had a significantly higher odds of diarrhea at the 6-month follow-up (OR, 1.79; 95% CI, 1.04 to 3.07). Children observed mouthing feces during structured observation had a significant reduction in height-for-age z-score (HAZ) from baseline to the 6-month follow-up (ΔHAZ, -0.69; 95% CI, -1.34 to -0.04). A significant reduction in HAZ was also observed for children with caregiver reports of touching guinea pigs (-0.33; 95% CI, -0.58 to -0.08) and rabbits (-0.34; 95% CI, -0.64 to -0.04) and children with feces in their sleeping space during unannounced spot checks (-0.41; 95% CI, -0.74 to -0.09). CONCLUSIONS: These findings emphasize the urgent need for infant water, sanitation, and hygiene interventions targeting child mouthing behaviors, fecal contamination in child living spaces, and child contact with domestic animals to reduce exposure to fecal pathogens among susceptible populations.

Child hand contamination is associated with subsequent pediatric diarrhea in rural Democratic Republic of the Congo (REDUCE Program).

OBJECTIVE: The Reducing Enteropathy, Undernutrition, and Contamination in the Environment (REDUCE) program focuses on identifying exposure pathways to faecal pathogens for young children in the Democratic Republic of the Congo (DRC) and on developing scalable interventions to reduce faecal contamination from these pathways. METHODS: A prospective cohort study of 690 participants was conducted to investigate the association between hand, food, and environmental faecal contamination and diarrhoeal disease prevalence among young children in Walungu Territory, South Kivu, DRC. A total of 1923 hand rinse, soil, food, object, surface, stored water and water source samples were collected during unannounced spot checks after baseline enrolment and analysed for Escherichia coli. Caregiver reports of diarrhoea were obtained from children < 5 years at a 6-month follow-up. RESULTS: E.coli was detected in 73% of child and caregiver hand-rinse samples, 69% of soil samples from child play spaces, 54% of child food samples, 38% of objects and surfaces children were observed putting in their mouths, 74% of stored water samples, and 40% of source water samples. Children < 5 years with E. coli on their hands had significantly higher odds of diarrhoea at the 6-month follow-up (odds ratio: 2.03 (95% confidence interval: 1.05, 3.92)). CONCLUSION: The cohort study findings from the REDUCE program have shown that child hand contamination is associated with diarrhoeal disease in rural DRC, and that there is high faecal contamination in child plays spaces and food. These findings provide evidence demonstrating the urgent need to provide clean play spaces for young children and interventions targeting hand hygiene to reduce paediatric exposure to faecal pathogens.

OBJECTIF: L'étude REDUCE (Réduire l'Entéropathie, la Dénutrition et la Contamination à partir de l'Environnement) se concentre sur l'identification des voies d'exposition aux pathogènes fécaux pour les jeunes enfants en République Démocratique du Congo (RDC) et sur le développement d'interventions évolutives pour réduire la contamination fécale par ces voies. MÉTHODES: Une étude de cohorte prospective de 690 participants a été menée pour étudier l'association entre la contamination fécale des mains, des aliments et de l'environnement et la prévalence des maladies diarrhéiques chez les jeunes enfants dans le Territoire de Walungu, dans le Sud-Kivu, en RDC. Un total de 1.923 échantillons de rinçages des mains, de sol, d'aliments, d'objets, de surfaces, d'eau stockée et de sources d'eau ont été collectés lors de contrôles ponctuels inopinés après l'inscription de base et analysés pour Escherichia coli. Les rapports des soignants concernant la diarrhée ont été obtenus pour les enfants de moins de 5 ans à un suivi de 6 mois. RÉSULTATS: E. coli a été détecté dans 73% des échantillons de rinçage des mains des enfants et des soignants, 69% des échantillons de sol des aires de jeux pour enfants, 54% des échantillons d'aliments pour enfants, 38% des objets et des surfaces que les enfants mettaient en bouche, 74 % des échantillons d'eau stockée et 40% des échantillons de sources d'eau. Les enfants de moins de 5 ans avec E. coli sur leurs mains avaient un risque de diarrhée significativement plus élevé au suivi de 6 mois (rapport de cotes: 2,03 (intervalle de confiance à 95%: 1,05, 3,92)). CONCLUSION: Les résultats de l'étude de cohorte du programme REDUCE ont montré que la contamination des mains des enfants est associée aux maladies diarrhéiques dans les régions rurales de la RDC et à une forte contamination fécale dans les aires de jeux et les aliments pour enfants. Ces résultats fournissent des données démontrant le besoin urgent de fournir des espaces de jeu propres aux jeunes enfants et des interventions ciblant l'hygiène des mains pour réduire l'exposition pédiatrique aux pathogènes fécaux.

Penalized regression models to select biomarkers of environmental enteric dysfunction associated with linear growth acquisition in a Peruvian birth cohort.

Environmental enteric dysfunction (EED) is associated with chronic undernutrition. Efforts to identify minimally invasive biomarkers of EED reveal an expanding number of candidate analytes. An analytic strategy is reported to select among candidate biomarkers and systematically express the strength of each marker's association with linear growth in infancy and early childhood. 180 analytes were quantified in fecal, urine and plasma samples taken at 7, 15 and 24 months of age from 258 subjects in a birth cohort in Peru. Treating the subjects' length-for-age Z-score (LAZ-score) over a 2-month lag as the outcome, penalized linear regression models with different shrinkage methods were fitted to determine the best-fitting subset. These were then included with covariates in linear regression models to obtain estimates of each biomarker's adjusted effect on growth. Transferrin had the largest and most statistically significant adjusted effect on short-term linear growth as measured by LAZ-score-a coefficient value of 0.50 (0.24, 0.75) for each log2 increase in plasma transferrin concentration. Other biomarkers with large effect size estimates included adiponectin, arginine, growth hormone, proline and serum amyloid P-component. The selected subset explained up to 23.0% of the variability in LAZ-score. Penalized regression modeling approaches can be used to select subsets from large panels of candidate biomarkers of EED. There is a need to systematically express the strength of association of biomarkers with linear growth or other outcomes to compare results across studies.

Effects of Child and Maternal Histo-Blood Group Antigen Status on Symptomatic and Asymptomatic Enteric Infections in Early Childhood.

BACKGROUND: Histo-blood group antigens (HBGAs) such as fucosyltransferase (FUT)2 and 3 may act as innate host factors that differentially influence susceptibility of individuals and their offspring to pediatric enteric infections. METHODS: In 3 community-based birth cohorts, FUT2 and FUT3 statuses were ascertained for mother-child dyads. Quantitative polymerase chain reaction panels tested 3663 diarrheal and 18 148 asymptomatic stool samples for 29 enteropathogens. Cumulative diarrhea and infection incidence were compared by child (n = 520) and mothers' (n = 519) HBGA status and hazard ratios (HRs) derived for all-cause diarrhea and specific enteropathogens. RESULTS: Children of secretor (FUT2 positive) mothers had a 38% increased adjusted risk of all-cause diarrhea (HR = 1.38; 95% confidence interval (CI), 1.15-1.66) and significantly reduced time to first diarrheal episode. Child FUT2 and FUT3 positivity reduced the risk for all-cause diarrhea by 29% (HR = 0.81; 95% CI, 0.71-0.93) and 27% (HR = 0.83; 95% CI, 0.74-0.92), respectively. Strong associations between HBGAs and pathogen-specific infection and diarrhea were observed, particularly for noroviruses, rotaviruses, enterotoxigenic Escherichia coli, and Campylobacter jejuni/coli. CONCLUSIONS: Histo-blood group antigens affect incidence of all-cause diarrhea and enteric infections at magnitudes comparable to many common disease control interventions. Studies measuring impacts of interventions on childhood enteric disease should account for both child and mothers' HBGA status.

Antibiotic Resistance of Campylobacter Species in a Pediatric Cohort Study.

The objective of this study was to determine the phenotypic patterns of antibiotic resistance and the epidemiology of drug-resistant Campylobacter spp. from a low-resource setting. A birth cohort of 303 patients was followed until 5 years of age. Stool samples from asymptomatic children (n = 10,008) and those with diarrhea (n = 3,175) were cultured for Campylobacter Disk diffusion for ciprofloxacin (CIP), nalidixic acid (NAL), erythromycin (ERY), azithromycin (AZM), tetracycline (TE), gentamicin (GM), ampicillin (AMP), amoxicillin and clavulanic acid (AMC), ceftriaxone (CRO), chloramphenicol (C), and trimethoprim-sulfamethoxazole (TMS) was determined. Antibiotic resistances in Campylobacter jejuni and non-C. jejuni isolates from surveillance and diarrhea samples were compared, and the association between personal macrolide exposure and subsequent occurrence of a macrolide-resistant Campylobacter spp. was assessed. Of 917 Campylobacter isolates, 77.4% of C. jejuni isolates and 79.8% of non-C. jejuni isolates were resistant to ciprofloxacin, while 4.9% of C. jejuni isolates and 24.8% of non-C. jejuni isolates were not susceptible to azithromycin. Of the 303 children, 33.1% had been diagnosed with a Campylobacter strain nonsusceptible to both azithromycin and ciprofloxacin. Personal macrolide exposure did not affect the risk of macrolide-resistant Campylobacter Amoxicillin and clavulanic acid (94.0%) was one of the antibiotics with the highest rates of susceptibility. There is a high incidence of quinolone- and macrolide-resistant Campylobacter infections in infants under 24 months of age. Given the lack of association between personal exposure to macrolides and a subsequent Campylobacter infection resistant to macrolides, there is a need to evaluate the source of multidrug-resistant (MDR) Campylobacter This study provides compelling evidence to propose amoxicillin/clavulanic acid as a treatment for campylobacteriosis.

Minimally Invasive Saliva Testing to Monitor Norovirus Infection in Community Settings.

BACKGROUND: Norovirus is a leading cause of acute gastroenteritis worldwide. Routine norovirus diagnosis requires stool collection. The goal of this study was to develop and validate a noninvasive method to diagnose norovirus to complement stool diagnostics and to facilitate studies on transmission. METHODS: A multiplex immunoassay to measure salivary immunoglobulin G (IgG) responses to 5 common norovirus genotypes (GI.1, GII.2, GII.4, GII.6, and GII.17) was developed. The assay was validated using acute and convalescent saliva samples collected from Peruvian children <5 years of age with polymerase chain reaction (PCR)-diagnosed norovirus infections (n = 175) and controls (n = 32). The assay sensitivity and specificity were calculated to determine infection status based on fold rise of salivary norovirus genotype-specific IgG using norovirus genotype from stool as reference. RESULTS: The salivary assay detected recent norovirus infections and correctly assigned the infecting genotype. Sensitivity was 71% and specificity was 96% across the evaluated genotypes compared to PCR-diagnosed norovirus infection. CONCLUSIONS: This saliva-based assay will be a useful tool to monitor norovirus transmission in high-risk settings such as daycare centers or hospitals. Cross-reactivity is limited between the tested genotypes, which represent the most commonly circulating genotypes.

The other Campylobacters: Not innocent bystanders in endemic diarrhea and dysentery in children in low-income settings.

BACKGROUND: Campylobacter is one of the main causes of gastroenteritis worldwide. Most of the current knowledge about the epidemiology of this food-borne infection concerns two species, C. coli and C. jejuni. Recent studies conducted in developing countries and using novel diagnostic techniques have generated evidence of the increasing burden and importance of other Campylobacter species, i.e. non-C. coli/jejuni. We performed a nested case-control study to compare the prevalence of C. coli/jejuni and other Campylobacter in children with clinical dysentery and severe diarrhea as well as without diarrhea to better understand the clinical importance of infections with Campylobacter species other than C. coli/jejuni. METHODOLOGY/PRINCIPAL FINDINGS: Our nested case-control study of 439 stool samples included dysenteric stools, stools collected during severe diarrhea episodes, and asymptomatic stools which were systematically selected to be representative of clinical phenotypes from 9,160 stools collected during a birth cohort study of 201 children followed until two years of age. Other Campylobacter accounted for 76.4% of the 216 Campylobacter detections by qPCR and were more prevalent than C. coli/jejuni across all clinical groups. Other Campylobacter were also more prevalent than C. coli/jejuni across all age groups, with older children bearing a higher burden of other Campylobacter. Biomarkers of intestinal inflammation and injury (methylene blue, fecal occult test, myeloperoxidase or MPO) showed a strong association with dysentery, but mixed results with infection. MPO levels were generally higher among children infected with C. coli/jejuni, but Shigella-infected children suffering from dysentery recorded the highest levels (26,224 ng/mL); the lowest levels (10,625 ng/mL) were among asymptomatic children infected with other Campylobacter. Adjusting for age, sex, and Shigella infection, dysentery was significantly associated with C. coli/jejuni but not with other Campylobacter, whereas severe diarrhea was significantly associated with both C. coli/jejuni and other Campylobacter. Compared to asymptomatic children, children suffering from dysentery had a 14.6 odds of C. coli/jejuni infection (p-value < 0.001, 95% CI 5.5-38.7) but were equally likely to have other Campylobacter infections-odds ratio of 1.3 (0.434, 0.7-2.4). Children suffering from severe diarrhea were more likely than asymptomatic children to test positive for both C. coli/jejuni and other Campylobacter-OR of 2.8 (0.034, 1.1-7.1) and 1.9 (0.018, 1.1-3.1), respectively. Compared to the Campylobacter-free group, the odds of all diarrhea given C. coli/jejuni infection and other Campylobacter infection were 8.8 (<0.001, 3.0-25.7) and 2.4 (0.002, 1.4-4.2), respectively. Eliminating other Campylobacter in this population would eliminate 24.9% of the diarrhea cases, which is almost twice the population attributable fraction of 15.1% due to C. coli/jejuni. CONCLUSIONS/SIGNIFICANCE: Eighty-seven percent of the dysentery and 59.5% of the severe diarrhea samples were positive for Campylobacter, Shigella, or both, emphasizing the importance of targeting these pathogens to limit the impact of dysentery and severe diarrhea in children. Notably, the higher prevalence of other Campylobacter compared to C. coli/jejuni, their increasing burden during early childhood, and their association with severe diarrhea highlight the importance of these non-C. coli/jejuni Campylobacter species and suggest a need to clarify their importance in the etiology of clinical disease across different epidemiological contexts.