Frequency of bystander exposure to antibiotics for enteropathogenic bacteria among young children in low-resource settings.

Children in low-resource settings carry enteric pathogens asymptomatically and are frequently treated with antibiotics, resulting in opportunities for pathogens to be exposed to antibiotics when not the target of treatment (i.e., bystander exposure). We quantified the frequency of bystander antibiotic exposures for enteric pathogens and estimated associations with resistance among children in eight low-resource settings. We analyzed 15,697 antibiotic courses from 1,715 children aged 0 to 2 y from the MAL-ED birth cohort. We calculated the incidence of bystander exposures and attributed exposures to respiratory and diarrheal illnesses. We associated bystander exposure with phenotypic susceptibility of E. coli isolates in the 30 d following exposure and at the level of the study site. There were 744.1 subclinical pathogen exposures to antibiotics per 100 child-years. Enteroaggregative Escherichia coli was the most frequently exposed pathogen, with 229.6 exposures per 100 child-years. Almost all antibiotic exposures for Campylobacter (98.8%), enterotoxigenic E. coli (95.6%), and typical enteropathogenic E. coli (99.4%), and the majority for Shigella (77.6%), occurred when the pathogens were not the target of treatment. Respiratory infections accounted for half (49.9%) and diarrheal illnesses accounted for one-fourth (24.6%) of subclinical enteric bacteria exposures to antibiotics. Bystander exposure of E. coli to class-specific antibiotics was associated with the prevalence of phenotypic resistance at the community level. Antimicrobial stewardship and illness-prevention interventions among children in low-resource settings would have a large ancillary benefit of reducing bystander selection that may contribute to antimicrobial resistance.

Cytokines, chemokines, and cells growth factors in patients with mild to moderate SARS-CoV-2 infection: A case-control study.

Several biomarkers have been evaluated as predictors of severity or in directing the treatment of COVID-19, however there are no conclusive results. In this study, we evaluated serum levels of cytokines, chemokines, and cell growth factors in association with the pathobiology of mild to moderate SARS-CoV-2 infection. Serum levels of SARS-CoV-2 infected patients (n = 113) and flu symptoms individuals negative for SARS-CoV-2 (n = 58), tested by the RT-qPCR test-nasal swab were compared to healthy controls (n = 53). Results showed that the proinflammatory cytokines IL-1ß, MCP-3, TNF-α, and G-CSF were increased in symptomatic patients and the cytokines IL-6 and IL-10 were associated with patients positive for SARS-CoV-2 when compared to healthy controls. Symptoms associated with COVID-19 were fever, anosmia, ageusia, and myalgia. For patients without SARS-CoV-2 infection, their major symptom was sore throat. The pathobiology of mild to moderate SARS-CoV-2 infection was associated with increasing proinflammatory cytokines and a pleiotropic IL-6 and anti-inflammatory IL-10 cytokines compared to healthy controls. Thus, knowledge about the pathophysiology and the involvement of biomarkers in the mild to moderate profile of the disease should be evaluated. Monitoring these biomarkers in patients with mild to moderate disease can help establish adequate treatment and prevention strategies for long-term COVID-19.

The Epidemiology of Sapovirus in the Etiology, Risk Factors, and Interactions of Enteric Infection and Malnutrition and the Consequences for Child Health and Development Study: Evidence of Protection Following Natural Infection.

BACKGROUND: Sapovirus is one of the principal agents of acute viral enteritis in children. Because it has not been routinely included in diagnostic evaluations, the epidemiology and natural history remain poorly described. METHODS: A birth cohort of 1715 children from 8 countries contributed surveillance samples (n = 35 620) and diarrheal specimens (n = 6868) from 0 to 24 months of age. Sapovirus was detected by quantitative polymerase chain reaction concurrently to other enteropathogens using multiarray cards. Logistic regression was used to identify risk factors, and longitudinal models were employed to estimate incidence rates and evaluate evidence of protective immunity. RESULTS: Sapovirus was detected in 24.7% (n = 1665) of diarrheal stools and 12.8% (n = 4429) of monthly surveillance samples. More than 90% of children were infected and 60% experienced sapovirus diarrhea in the first 2 years of life. Breastfeeding and higher socioeconomic status were associated with reduced incidence of infection and illness. Specimens with sapovirus detected had an increased odds of coinfection with rotavirus (odds ratio [OR], 1.6 [95% confidence interval {CI}, 1.3-2.0]), astrovirus (OR, 1.5 [95% CI, 1.3-1.7]), adenovirus (OR, 1.3 [95% CI, 1.1-1.5]), and Shigella (OR, 1.4 [95% CI, 1.3-1.6]). Prior infection with sapovirus conferred a risk reduction of 22% for subsequent infection (hazard ratio [HR], 0.78 [95% CI, .74-.85]) and 24% for subsequent diarrhea (95% CI, 11.0%-35.0%; HR, 0.76). CONCLUSIONS: Sapovirus is a common cause of early childhood diarrhea. Further research on coinfections is warranted. Evidence of acquired immunity was observed even in the absence of genotype-specific analysis for this pathogen of known genetic diversity.

Detection of SARS-CoV-2 in different human biofluids using the loop-mediated isothermal amplification assay: A prospective diagnostic study in Fortaleza, Brazil.

We adopted the reverse-transcriptase-loop-mediated isothermal amplification (RT-LAMP) to detect severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) in patient samples. Two primer sets for genes N and Orf1ab were designed to detect SARS-CoV-2, and one primer set was designed to detect the human gene Actin. We collected prospective 138 nasopharyngeal swabs, 70 oropharyngeal swabs, 69 salivae, and 68 mouth saline wash samples from patients suspected to have severe acute respiratory syndrome (SARS) caused by SARS-CoV-2 to test the RT-LAMP in comparison with the gold standard technique reverse-transcription quantitative polymerase chain reaction  (RT-qPCR). The accuracy of diagnosis using both primers, N5 and Orf9, was evaluated. Sensitivity and specificity for diagnosis were 96% (95% confidence interval [CI]: 87-99) and 85% (95% CI: 76-91) in 138 samples, respectively. Accurate diagnosis results were obtained only in nasopharyngeal swabs processed via extraction kit. Accurate and rapid diagnosis could aid coronavirus disease 2019 (COVID-19) pandemic management by identifying, isolating, and treating patients rapidly.

Duration of Postdiarrheal Enteric Pathogen Carriage in Young Children in Low-resource Settings.

BACKGROUND: Prolonged enteropathogen shedding after diarrhea complicates the identification of etiology in subsequent episodes and is an important driver of pathogen transmission. A standardized approach has not been applied to estimate the duration of shedding for a wide range of pathogens. METHODS: We used a multisite birth cohort of children 0-24 months of age from whom diarrheal and monthly nondiarrheal stools were previously tested by quantitative polymerase chain reaction for 29 enteropathogens. We modeled the probability of detection of the etiologic pathogen before and after diarrhea using a log-normal accelerated failure time survival model and estimated the median duration of pathogen carriage as well as differences in subclinical pathogen carriage 60 days after diarrhea onset in comparison to a prediarrhea baseline. RESULTS: We analyzed 3247 etiologic episodes of diarrhea for the 9 pathogens with the highest attributable burdens of diarrhea. The median duration of postdiarrheal carriage varied widely by pathogen, from about 1 week for rotavirus (median, 8.1 days [95% confidence interval {CI}, 6.2-9.6]) to >1 month for Cryptosporidium (39.5 days [95% CI, 30.6-49.0]). The largest increases in subclinical pathogen carriage before and after diarrhea were seen for Cryptosporidium (prevalence difference between 30 days prior and 60 days after diarrhea onset, 0.30 [95% CI, .23-.39]) and Shigella (prevalence difference, 0.21 [95% CI, .16-.27]). CONCLUSIONS: Postdiarrheal shedding was widely variable between pathogens, with strikingly prolonged shedding seen for Cryptosporidium and Shigella. Targeted antimicrobial therapy and vaccination for these pathogens may have a relatively large impact on transmission.

Perinatal Outcomes of Asynchronous Influenza Vaccination, Ceará, Brazil, 2013-2018.

In Ceará, Brazil, seasonal influenza transmission begins before national annual vaccination campaigns commence. To assess the perinatal consequences of this misalignment, we tracked severe acute respiratory infection (SARI), influenza, and influenza immunizations during 2013-2018. Among 3,297 SARI cases, 145 (4.4%) occurred in pregnant women. Statewide vaccination coverage was >80%; however, national vaccination campaigns began during or after peak influenza season. Thirty to forty weeks after peak influenza season, birthweights decreased by 40 g, and rates of prematurity increased from 10.7% to 15.5%. We identified 61 children born to mothers with SARI during pregnancy; they weighed 10% less at birth and were more likely to be premature than 122 newborn controls. Mistiming of influenza vaccination campaigns adversely effects perinatal outcomes in Ceará. Because Ceará is the presumptive starting point for north-to-south seasonal influenza transmission in Brazil, earlier national immunization campaigns would provide greater protection for pregnant women and their fetuses in Ceará and beyond.

Higher Energy and Zinc Intakes from Complementary Feeding Are Associated with Decreased Risk of Undernutrition in Children from South America, Africa, and Asia.

BACKGROUND: Few studies have focused on quantitatively analyzing nutrients from infant diets, compromising complementary feeding evaluation and health promotion worldwide. OBJECTIVES: This study aimed to describe dietary intake in infants from 9 to 24 mo of age, determining nutrient intakes associated with the risk of underweight, wasting, and stunting. METHODS: Usual nutrient intakes from complementary feeding were determined by 24-h recalls collected when infants were 9-24 mo of age in communities from 7 low- and middle-income countries: Brazil (n = 169), Peru (n = 199), South Africa (n = 221), Tanzania (n = 210), Bangladesh (n = 208), India (n = 227), and Nepal (n = 229), totaling 1463 children and 22,282 food recalls. Intakes were corrected for within- and between-person variance and energy intake. Multivariable regression models were constructed to determine nutrient intakes associated with the development of underweight, wasting, and stunting at 12, 18, and 24 mo of age. RESULTS: Children with malnutrition presented significantly lower intakes of energy and zinc at 12, 18, and 24 mo of age, ranging from -16.4% to -25.9% for energy and -2.3% to -48.8% for zinc. Higher energy intakes decreased the risk of underweight at 12 [adjusted odds ratio (AOR): 0.90; 95% CI: 0.84, 0.96] and 24 mo (AOR: 0.91; 95% CI: 0.86, 0.96), and wasting at 18 (AOR: 0.91; 95% CI: 0.83, 0.99) and 24 mo (AOR: 0.83; 95% CI: 0.74, 0.92). Higher zinc intakes decreased the risk of underweight (AOR: 0.12; 95% CI: 0.03, 0.55) and wasting (AOR: 0.19; 95% CI: 0.04, 0.92) at 12 mo, and wasting (AOR: 0.05; 95% CI: 0.00, 0.76) at 24 mo. CONCLUSIONS: Higher intakes of energy and zinc in complementary feeding were associated with decreased risk of undernutrition in the studied children. Data suggest these are characteristics to be improved in children's complementary feeding across countries.

Protection From Natural Immunity Against Enteric Infections and Etiology-Specific Diarrhea in a Longitudinal Birth Cohort.

BACKGROUND: The degree of protection conferred by natural immunity is unknown for many enteropathogens, but it is important to support the development of enteric vaccines. METHODS: We used the Andersen-Gill extension of the Cox model to estimate the effects of previous infections on the incidence of subsequent subclinical infections and diarrhea in children under 2 using quantitative molecular diagnostics in the MAL-ED cohort. We used cross-pathogen negative control associations to correct bias due to confounding by unmeasured heterogeneity of exposure and susceptibility. RESULTS: Prior rotavirus infection was associated with a 50% lower hazard (calibrated hazard ratio [cHR], 0.50; 95% confidence interval [CI], 0.41-0.62) of subsequent rotavirus diarrhea. Strong protection was evident against Cryptosporidium diarrhea (cHR, 0.32; 95% CI, 0.20-0.51). There was also protection due to prior infections for norovirus GII (cHR against diarrhea, 0.67; 95% CI, 0.49-0.91), astrovirus (cHR, 0.62; 95% CI, 0.48-0.81), and Shigella (cHR, 0.79; 95% CI, 0.65-0.95). Minimal protection was observed for other bacteria, adenovirus 40/41, and sapovirus. CONCLUSIONS: Natural immunity was generally stronger for the enteric viruses than bacteria, potentially due to less antigenic diversity. Vaccines against major causes of diarrhea may be feasible but likely need to be more immunogenic than natural infection.

Intervention and Mechanisms of Alanyl-glutamine for Inflammation, Nutrition, and Enteropathy: A Randomized Controlled Trial.

OBJECTIVE: Determine the minimum dosage of alanyl-glutamine (Ala-Gln) required to improve gut integrity and growth in children at risk of environmental enteropathy (EE). METHODS: This was a double-blinded randomized placebo-controlled dose-response trial. We enrolled 140 children residing in a low-income community in Fortaleza, Brazil. Participants were 2 to 60 months old and had weight-for-age (WAZ), height-for-age (HAZ), or weight-for-height (WHZ) z-scores less than -1. We randomized children to 10 days of nutritional supplementation: Ala-Gln at 3 g/day, Ala-Gln at 6 g/day, Ala-Gln at 12 g/day, or an isonitrogenous dose of glycine (Gly) placebo at 12.5 g/day. Our primary outcome was urinary lactulose-mannitol excretion testing. Secondary outcomes were anthropometry, fecal markers of inflammation, urine metabolic profiles, and malabsorption (spot fecal energy). RESULTS: Of 140 children, 103 completed 120 days of follow-up (24% dropout). In the group receiving the highest dose of Ala-Gln, we detected a modest improvement in urinary lactulose excretion from 0.19% on day 1 to 0.17% on day 10 (P = 0.05). We observed significant but transient improvements in WHZ at day 10 in 2 Ala-Gln groups, and in WHZ and WAZ in all Ala-Gln groups at day 30. We detected no effects on fecal inflammatory markers, diarrheal morbidity, or urine metabolic profiles; but did observe modest reductions in fecal energy and fecal lactoferrin in participants receiving Ala-Gln. CONCLUSIONS: Intermediate dose Ala-Gln promotes short-term improvement in gut integrity and ponderal growth in children at risk of EE. Lower doses produced improvements in ponderal growth in the absence of enhanced gut integrity.

Virulence-Related Genes and Coenteropathogens Associated with Clinical Outcomes of Enteropathogenic Escherichia coli Infections in Children from the Brazilian Semiarid Region: a Case-Control Study of Diarrhea.

Enteropathogenic Escherichia coli (EPEC) is a major cause of diarrhea in children from developing countries and presents high genetic variability. We aimed to characterize the EPEC virulence-related gene (VRG) distribution and copathogens associated with diarrhea and nutrition-related outcomes in children from the low-income Brazilian semiarid region. A cross-sectional case-control study of diarrhea was conducted in 1,191 children aged 2 to 36 months from the northeast region of Brazil. Stool samples were collected and clinical, epidemiological, and anthropometric data were identified from each child. A broad molecular evaluation of enteropathogens was performed, and EPEC-positive samples were further investigated for 18 VRGs using five multiplex PCRs. EPEC was detected in 28.2% of the study population, with similar proportions among cases and controls. Typical EPEC (tEPEC) infections were more often associated with diarrhea than atypical EPEC (aEPEC) infections, while aEPEC infections presented a higher prevalence. The VRG ler, a negative regulator of the locus of enterocyte effacement, was associated with the absence of diarrhea in aEPEC-positive children; espB, a major component of the type 3 secretion system, was associated with diarrhea in tEPEC-positive children; the presence of procolonization VRGs-the combination of cesT positivity, espP negativity, and the presence of the map gene-was associated with undernutrition; and Campylobacter spp., norovirus, and enteroaggregative E. coli (EAEC) coinfections were associated with increased clinical severity in EPEC-infected children. These data identified tEPEC strains associated with diarrhea and specific VRGs of EPEC (ler, espB, cesT, and map genes) and Campylobacter spp., norovirus, and EAEC to be major contributors to diarrhea and undernutrition in children from a low-income Brazilian region.

Rotavirus A Infections in Community Childhood Diarrhea in the Brazilian Semiarid Region During Postvaccination Era.

BACKGROUND: Rotavirus A (RVA) is one of the leading causes of acute gastroenteritis worldwide; however, few studies assessed RVA genetics with community surveillance. OBJECTIVES: This study aimed to investigate clinical data, genetic diversity, and coinfection patterns of RVA infections in children from 2 to 36 months old with or without community childhood diarrhea in the Brazilian semiarid region during postvaccination era. METHODS: We enrolled and collected socioeconomic/clinical information using a standardized questionnaire and fecal samples from 291 children. Viral RNA samples were extracted and analyzed using quantitative reverse transcription polymerase chain reaction to establish the diagnosis of RVA. Sequencing of VP7 and VP4 (VP8*) regions and phylogenetic analysis were performed. RESULTS: RVA-negative diagnosis was associated with children 24 to 36 months old with complete vaccination schedule. Genotype G1P[8] was the most prevalent (57%), whereas unusual genotypes including G1P[4], G2P[8], and G3P[9] were also detected. G1- and P[8]-positive samples showed high degrees of similarity with the vaccine strain. RVA coinfections were frequently observed, and enteroaggregative Escherichia coli was the most prevalent copathogen. CONCLUSIONS: These results demonstrate that genotype G1P[8] is the most prevalent strain. VP7 and/or VP8* gene segments arising from RV1 vaccine strain were documented in these children, suggesting shedding or herd vaccination. Moreover, our study indicates full vaccination is important for protection against RVA infections.

Alanyl-glutamine Protects Against Damage Induced by Enteroaggregative Escherichia coli Strains in Intestinal Cells.

BACKGROUND: Enteroaggregative Escherichia coli (EAEC) is an important pathogen causing enteric infections worldwide. This pathotype is linked to malnutrition in children from developing countries. Alanyl-glutamine (Ala-Gln) is an immune modulator nutrient that acts during intestinal damage and/or inflammation. This study investigated the effect of EAEC infection and Ala-Gln on cell viability, cell death, and inflammation of intestinal epithelium cells (IEC-6). METHODS: Cells were infected with an EAEC prototype 042 strain, an EAEC wild-type strain isolated from a Brazilian malnourished child, and a commensal E coli HS. Gene transcription and protein levels of caspases-3, -8, and -9 and cytokine-induced neutrophil chemoattractant 1 (CINC-1/CXCL1) were evaluated using RT-qPCR, western blot analysis, and ELISA. RESULTS: Infections with both EAEC strains decreased cell viability and induced apoptosis and necrosis after 24 hours. Ala-Gln supplementation increased cell proliferation and reduced cell death in infected cells. Likewise, EAEC strain 042 significantly increased the transcript levels of caspases-3, -8, and -9 when compared to the control group, and Ala-Gln treatment reversed this effect. Furthermore, EAEC induced CXCL1 protein levels, which were also reduced by Ala-Gln supplementation. CONCLUSION: These findings suggest that EAEC infection promotes apoptosis, necrosis, and intestinal inflammation with involvement of caspases. Supplementation of Ala-Gln inhibits cell death, increases cell proliferation, attenuates mediators associated with cell death, and inflammatory pathways in infected cells.

Epidemiology and Risk Factors for Cryptosporidiosis in Children From 8 Low-income Sites: Results From the MAL-ED Study.

Background: Cryptosporidium species are enteric protozoa that cause significant morbidity and mortality in children worldwide. We characterized the epidemiology of Cryptosporidium in children from 8 resource-limited sites in Africa, Asia, and South America. Methods: Children were enrolled within 17 days of birth and followed twice weekly for 24 months. Diarrheal and monthly surveillance stool samples were tested for Cryptosporidium by enzyme-linked immunosorbent assay. Socioeconomic data were collected by survey, and anthropometry was measured monthly. Results: Sixty-five percent (962/1486) of children had a Cryptosporidium infection and 54% (802/1486) had at least 1 Cryptosporidium-associated diarrheal episode. Cryptosporidium diarrhea was more likely to be associated with dehydration (16.5% vs 8.3%, P < .01). Rates of Cryptosporidium diarrhea were highest in the Peru (10.9%) and Pakistan (9.2%) sites. In multivariable regression analysis, overcrowding at home was a significant risk factor for infection in the Bangladesh site (odds ratio, 2.3 [95% confidence interval {CI}, 1.2-4.6]). Multiple linear regression demonstrated a decreased length-for-age z score at 24 months in Cryptosporidium-positive children in the India (ß = -.26 [95% CI, -.51 to -.01]) and Bangladesh (ß = -.20 [95% CI, -.44 to .05]) sites. Conclusions: This multicountry cohort study confirmed the association of Cryptosporidium infection with stunting in 2 South Asian sites, highlighting the significance of cryptosporidiosis as a risk factor for poor growth. We observed that the rate, age of onset, and number of repeat infections varied per site; future interventions should be targeted per region to maximize success.

Genome-Wide Analysis in Brazilians Reveals Highly Differentiated Native American Genome Regions.

Despite its population, geographic size, and emerging economic importance, disproportionately little genome-scale research exists into genetic factors that predispose Brazilians to disease, or the population genetics of risk. After identification of suitable proxy populations and careful analysis of tri-continental admixture in 1,538 North-Eastern Brazilians to estimate individual ancestry and ancestral allele frequencies, we computed 400,000 genome-wide locus-specific branch length (LSBL) Fst statistics of Brazilian Amerindian ancestry compared to European and African; and a similar set of differentiation statistics for their Amerindian component compared with the closest Asian 1000 Genomes population (surprisingly, Bengalis in Bangladesh). After ranking SNPs by these statistics, we identified the top 10 highly differentiated SNPs in five genome regions in the LSBL tests of Brazilian Amerindian ancestry compared to European and African; and the top 10 SNPs in eight regions comparing their Amerindian component to the closest Asian 1000 Genomes population. We found SNPs within or proximal to the genes CIITA (rs6498115), SMC6 (rs1834619), and KLHL29 (rs2288697) were most differentiated in the Amerindian-specific branch, while SNPs in the genes ADAMTS9 (rs7631391), DOCK2 (rs77594147), SLC28A1 (rs28649017), ARHGAP5 (rs7151991), and CIITA (rs45601437) were most highly differentiated in the Asian comparison. These genes are known to influence immune function, metabolic and anthropometry traits, and embryonic development. These analyses have identified candidate genes for selection within Amerindian ancestry, and by comparison of the two analyses, those for which the differentiation may have arisen during the migration from Asia to the Americas.

Enteroaggregative Escherichia coli subclinical and clinical infections.

PURPOSE OF REVIEW: The current review is to update the results on epidemiology, pathobiology, and genes related to virulence, clinical presentation, molecular diagnosis, antimicrobial resistance, and extraintestinal infection of enteroaggregative Escherichia coli (EAEC). RECENT FINDINGS: EAEC subclinical infection was significantly associated with reduced length at 2 years of age and EAEC and coinfections were associated with reduced delta weight-for-length and weight-for-age z-scores in the first 6 months of age in the MAL-ED birth cohort study. EAEC was associated with malnutrition in children 6-24 months of age in prospective case-control studies in Bangladesh and Brazil. Virulence gene-based studies have suggested aggregative fimbriae II may be a major contributor to disease, whereas AggR-activated regulator a marker of less severe disease. The high ability of EAEC colonization likely exacerbates effects of other microbial virulence strategies. Molecular diagnosis has been useful for understanding EAEC burden, although different criteria may relate to different pathogenic outcomes. SUMMARY: EAEC gained special interest in the past few years, especially due to association with growth decrements in children with subclinical infections and its important role as a copathogen. Understanding of EAEC pathogenesis advanced but further research is needed for elucidating both microbial and host factors influencing infection outcomes.

Campylobacter jejuni virulence genes and immune-inflammatory biomarkers association with growth impairment in children from Northeastern Brazil.

Campylobacter spp. have been associated with anthropometric Z-score decrements, but the role of specific virulence genes associated with these outcomes has not been explored. This study aimed to investigate whether specific Campylobacter jejuni virulence-related gene and immune-inflammatory biomarkers are associated with malnutrition in children from Northeastern Brazil. A case-control study was performed in Fortaleza, Brazil. Children aging 6-24 months were characterized as malnourished (cases) if weight-for-age Z-score (WAZ) = 2 and as nourished (controls) if WAZ ≥ 1. DNA samples were extracted from stools and screened for C. jejuni/coli by real-time PCR. A subsequent C. jejuni-specific PCR was employed and positive samples were evaluated for 18 C. jejuni virulence genes by using four multiplex PCRs. C. jejuni was detected in 9.71% (33/340) of the children's samples, being 63.63% (21/33) from nourished and 37.37% (12/33) from malnourished children. The cadF, iamA, cheW, and sodB genes were the most frequent genes (100%, 90.9%, 87.9%, and 75.8%, respectively), while some others (ceuE, jlpA, pldA, and pVir) showed low rates (all below 6%). Malnourished children were significantly associated with infection with C. jejuni strains lacking cdtB gene (active subunit of cytolethal distending toxin) and harboring flgE gene (flagellar hook protein). These strains were also associated with children presenting increased serum SAA and sCD-14, but decreased IgG anti-LPS. These data reinforce the impact of Campylobacter jejuni infection on children without diarrhea and highlight the contribution of a specific virulence gene profile, cdtB(-)flgE(+) and increased systemic response in malnutrition children.

Genetic Diversity of Norovirus Infections, Coinfections, and Undernutrition in Children From Brazilian Semiarid Region.

BACKGROUND AND OBJECTIVE: Norovirus (NoV) infections are known to have high-morbidity and mortality rates and are a major health problem globally. The impact of NoV on child development is, however, poorly understood. We evaluated the distribution of NoV genotypes in children from a low-income Brazilian semiarid region, in relation with their clinical symptoms, nutritional status, and co-pathogens. METHODS: The test population included children aged 2 to 36 months from 6 cities of the Brazilian semiarid region. Fecal samples were collected from each child, along with the information regarding their socioeconomic/clinical conditions using a standardized questionnaire. Detection and quantification of NoV were performed by reverse-transcription quantitative polymerase chain reaction, followed by molecular and phylogenetic analyses. RESULTS: The NoV detection rate was 45.2%. Presence of NoV was associated with lower z scores for weight-for-age (P = 0.03), weight-for-height (P = 0.03), and body mass index-for-age (P = 0.03). NoV infection was associated with more frequent respiratory illnesses (P < 0.01). GII.P7 (polymerase) and GII.3 (capsid) were the most frequent NoV genotypes. Analysis of the open reading frame (ORF)1-2 junction identified recombinant NoV strains in 80% of the sequenced samples. Enteroaggregative Escherichia coli coinfection was the major predictor for diarrhea in NoV-positive samples (P < 0.02). Moreover, Shigella spp was also associated with NoV-positive diagnosis (P = 0.02). CONCLUSIONS: This study highlights the genetic variability of NoV and, associated co-infections and undernutrition in infants from low-income Brazilian semiarid region.

Enteroaggregative Escherichia coli Subclinical Infection and Coinfections and Impaired Child Growth in the MAL-ED Cohort Study.

OBJECTIVE: We evaluated the impact of subclinical enteroaggregative Escherichia coli (EAEC) infection alone and in combination with other pathogens in the first 6 months of life on child growth. METHODS: Nondiarrheal samples from 1684 children across 8 Multisite Birth Cohort Study, Malnutrition and Enteric Diseases (MAL-ED) sites in Asia, Africa, and Latin America were tested monthly; more than 90% of children were followed-up twice weekly for the first 6 months of life. RESULTS: Children with subclinical EAEC infection did not show altered growth between enrollment and 6 months. Conversely, EAEC coinfection with any other pathogen was negatively associated with delta weight-for-length (P < 0.05) and weight-for-age (P > 0.05) z scores between 0 and 6 months. The presence of 2 or more pathogens without EAEC was not significantly associated with delta weight-for-length and weight-for-age. The most frequent EAEC coinfections included Campylobacter spp, heat-labile toxin-producing enterotoxigenic E coli, Cryptosporidium spp, and atypical enteropathogenic E coli. Myeloperoxidase levels were increased with EAEC coinfection (P < 0.05). EAEC pathogen codetection was associated with lower neopterin levels compared to those of no-pathogen control children (P < 0.05). Mothers of children with EAEC coinfections had lower levels of education, poorer hygiene and sanitation, lower socioeconomic status, and lower breast-feeding rates compared to mothers of children in whom no pathogen was detected (P < 0.05). CONCLUSIONS: These data emphasize the public health importance of subclinical EAEC infection in early infancy in association with other pathogens and the need for improved maternal and child care, hygiene, sanitation, and socioeconomic factors.

Rotavirus Infection and Disease in a Multisite Birth Cohort: Results From the MAL-ED Study.

Background: In a multicountry birth cohort study, we describe rotavirus infection in the first 2 years of life in sites with and without rotavirus vaccination programs. Methods: Children were recruited by 17 days of age and followed to 24 months with collection of monthly surveillance and diarrheal stools. Data on sociodemographics, feeding, and illness were collected at defined intervals. Stools were tested for rotavirus and sera for antirotavirus immunoglobulins by enzyme immunoassays. Results: A total of 1737 children contributed 22646 surveillance and 7440 diarrheal specimens. Overall, rotavirus was detected in 5.5% (408/7440) of diarrheal stools, and 344 (19.8%) children ever had rotavirus gastroenteritis. Household overcrowding and a high pathogen load were consistent risk factors for infection and disease. Three prior infections conferred 74% (P < .001) protection against subsequent infection in sites not using vaccine. In Peru, incidence of rotavirus disease was relatively higher during the second year of life despite high vaccination coverage. Conclusions: Rotavirus infection and disease were common, but with significant heterogeneity by site. Protection by vaccination may not be sustained in the second year of life in settings with high burdens of transmission and poor response to oral vaccines.

Early Antibiotic Exposure in Low-resource Settings Is Associated With Increased Weight in the First Two Years of Life.

OBJECTIVES: The potential growth-promoting effects of antibiotics are not well understood among undernourished children in environments with high pathogen exposure. We aimed to assess whether early antibiotic exposure duration and class were associated with growth to 2 years of age across 8 low-resource sites in the MAL-ED birth cohort study. METHODS: We followed 1954 children twice per week from birth to 2 years to record maternally reported antibiotic exposures and measure anthropometry monthly. We estimated the associations between antibiotic exposure before 6 months of age and weight-for-age and length-for-age (LAZ) z scores to 2 years. We assessed the impact of class-specific exposures and duration, and compared these results to effects of antibiotic exposures after 6 months of age. RESULTS: Antibiotic use before 6 months of age was associated with increased weight from 6 months to 2 years, whereas associations with length were less consistent across sites and antibiotic classes. Compared to unexposed children, 2 or more courses of metronidazole, macrolides, and cephalosporins were associated with adjusted increases in weight-for-age of 0.24 (95% confidence interval (CI): 0.04, 0.43), 0.23 (95% CI: 0.05, 0.42), and 0.19 (95% CI: 0.04, 0.35) from 6 months to 2 years, respectively. CONCLUSIONS: Antibiotic use in low-resource settings was most associated with the ponderal growth of children who had multiple exposures to antibiotics with broad spectrum and anaerobic activity in early infancy. Opportunities for rational and targeted antibiotic therapy in low resource settings may also promote short-term weight gain in children, although longer-term physical growth and metabolic impacts are unknown.