Search

Background: Helicobacter pylori is acquired largely in early childhood, but its association with symptoms and indirect biomarkers of gastric damage in apparently healthy children remains controversial. We aimed to relate persistent H. pylori infection in apparently healthy school-aged children with clinical, laboratory, and noninvasive biomarkers suggestive of gastric damage using a case-control design. Materials and methods: We followed up 83 children aged 4–5 years with persistent H. pylori infection determined by stool antigen detection and/or a urea breath test and 80 noninfected matched controls from a low-income to middle-income, periurban city in Chile for at least 3 years. Monitoring included clinical visits every 4 months and annual assessment by a pediatric gastroenterologist. A blood sample was obtained to determine laboratory parameters potentially associated with gastric damage (hemogram and serum iron and ferritin levels), biomarkers of inflammation (cytokines, pepsinogens I and II, and tissue inhibitor metalloproteinase 1), and expression of cancer-related genes KLK1, BTG3, and SLC5A8. Results: Persistently infected children had higher frequency of epigastric pain on physical examination (40% versus 16%; P = 0.001), especially from 8 to 10 years of age. No differences in anthropometric measurements or iron-deficiency parameters were found. Persistent infection was associated with higher levels of pepsinogen II (median 12.7 ng/mL versus 9.0 ng/mL; P

En el proceso de investigación clínica, la formulación de una hipótesis bien fundamentada y objetivos concordantes con la pregunta de investigación, son claves para la adecuada conducción del proyecto. El siguiente artículo revisa los principios fundamentales para la formulación adecuada de hipótesis y objetivos de proyectos de investigación clínica, proporcionando recomendaciones prácticas y ejemplos.

Objective: To determine the dynamics of norovirus disease, a major cause of acute gastroenteritis (AGE), compared to other relevant etiologies, among families living in a lower middle income area. Study design: Families with three or more members and with one or more healthy children

OBJECTIVES Helicobacter pylori (H. pylori) is the primary cause of gastric cancer and eradication in healthy adults has proven effective in decreasing cancer incidence. H. pylori is acquired largely in early childhood, however, the benefits of eradication in children are controversial. We aimed to determine the effect of H. pylori eradication on clinical and laboratory markers associated with gastric damage in apparently healthy school-aged children. METHODS This was a pilot non-blinded trial including 61 children persistently infected with H. pylori who were randomized to eradication/no treatment and followed for at least 12 months, evaluating clinical and blood markers (Pepsinogen I (PGI) and II (PGII) determined by ELISA) associated with gastric damage. The treatment consisted of a sequential scheme including 7 days of omeprazole + amoxicillin followed by 7 days of omeprazole + clarithromycin + metronidazole; adherence and tolerance were surveyed. Eradication rates were assessed by stool antigen detection or urea breath test 1 month following treatment every 4 months thereafter to detect reinfection. RESULTS Eradication occurred in 30/31 treated children (median age: 8.8, range: 7.9-10.8) and in 0/30 non-treated controls (median age: 8.6, range: 7.9-11) (p

Fructose is a highly abundant carbohydrate in western diet and may induce bowel symptoms in children as in adults. The main objective of this study is to describe the frequency of fructose malabsorption (FM) in symptomatic patients 18 years or younger undergoing fructose breath test in a single tertiary center between 2013 and 2018, and to evaluate whether certain symptoms are related to positivity of the test. Out of 273 tests 183 (67%) were compatible with FM. The most frequent pretest symptom in the overall study population was bloating (83%), followed by abdominal pain (73%). Patients with positive test were younger than those with a negative test (median 5 vs 8 years, P

The latest joint H. pylori NASPGHAN and ESPGHAN clinical guidelines published in 2016, contain 20 statements that have been questioned in practice regarding their applicability in Latin America (LA); in particular in relation to gastric cancer prevention.We conduc ted a critical analysis of the literature, with special emphasis on LA data and established the level of evidence and level of recommendation of the most controversial claims in the Joint Guidelines. Two rounds of voting were conducted according to the Delphi consensus technique and a Likert scale (from 0 to 4) was used to establish the "degree of agreement" among a panel of SLAGHNP ex perts.There are few studies regarding diagnosis, treatment effectiveness and susceptibility to antibiotics of H. pylori in pediatric patients of LA. Based on these studies, extrapolations from adult studies, and the clinical experience of the participating expert panel, the following recom mendations are made. We recommend taking biopsies for rapid urease and histology testing (and samples for culture or molecular techniques, when available) during upper endoscopy only if in case of confirmed H. pylori infection, eradication treatment will be indicated. We recommend that selected regional centers conduct antimicrobial sensitivity/resistance studies for H. pylori and thus act as reference centers for all LA. In case of failure to eradicate H. pylori with first-line treatment, we recommend empirical treatment with quadruple therapy with proton pump inhibitor, amoxi cillin, metronidazole, and bismuth for 14 days. In case of eradication failure with the second line scheme, it is recommended to indicate an individualized treatment considering the age of the pa tient, the previously indicated scheme and the antibiotic sensitivity of the strain, which implies performing a new endoscopy with sample extraction for culture and antibiogram or molecular resistance study. In symptomatic children referred to endoscopy who have a history of first or se cond degree family members with gastric cancer, it is recommended to consider the search for H. pylori by direct technique during endoscopy (and eradicate it when detected).The evidence supports most of the general concepts of the NASPGHAN/ESPGHAN 2016 Guidelines, but it is necessary to adapt them to the reality of LA, with emphasis on the development of regional centers for the study of antibiotic sensitivity and to improve the correct selection of the eradication treatment. In symptomatic children with a family history of first or second degree gastric cancer, the search for and eradication of H. pylori should be considered.

Objectives The aim of the study was to compare the cow's milk protein allergy (CMPA) prevalence in 2 cohorts of children from different socioeconomic strata. Methods Prospective birth cohort that included patients from 2 hospitals providing care for a low- and high-income population, respectively. Healthy newborns ≥34 gestational weeks were recruited and followed up to 12 months by a monthly telephone survey. If ≥2 predefined symptoms/signs suggestive of CMPA were detected, the patient was evaluated by a pediatric gastroenterologist. Diagnosis was confirmed by exclusion diet followed by open oral food challenge. Results Overall the prevalence of CMPA was 5.2%, with a 6 times higher prevalence in the high income cohort (9.2%) compared with the low-income group (1.5%; relative risk 6.2; 95% confidence interval 1.8-20.7; P = 0.0005). All the cases were non-immunoglobulin E-mediated with predominantly gastrointestinal symptoms. High-income cohort did have higher frequency of C-section, mother's previous chronic disease, mother's history of atopy/food allergy, older age, and higher educational level of parents. Parent smoking and presence of pets at home were more frequent in the low-income cohort. Multiple logistic regression showed that the high-income cohort did have older age and higher educational level of both parents. Conclusion In these cohorts the prevalence of CMPA was higher than reported previously in other developing countries and significantly higher in the high-income group. Our findings were associated with sociodemographic characteristics of the parents.

Gluten and other related proteins of the wheat, rye and barley, have antigenic properties that may trigger adverse reactions in susceptible individuals. Celiac disease was the first pathology with clear causal association related to the intake of these proteins. Recently, wheat allergy and non celiac gluten sensitivity have been described. Although, clinical presentation and its relation with protein ingestion may be similar and elicit confusion, their pathogenic mechanism, diagnosis and treatment are quite different. Since the prevalence of these diseases is relatively high as a whole, it is essential that these become familiar to primary care doctors and general pediatricians, thus they will know how to differentiate and face them. The aim of this review is to compare the main aspects of epidemiology, pathofisiology, diagnosis and treatment of these 3 conditions.

ResumenIntroducciónLa alergia a proteína de leche de vaca (APLV) es frecuente en lactantes (2-5% en

Lactase nonpersistence (LNP) in humans is a genetically determined trait. This age-dependent decrease of lactase expression is most frequently caused by single nucleotide polymorphisms in the regulatory region of the lactase (LCT) gene. The homozygous LCT-13,910C/C genotype (rs 4988235) predominates in Caucasian adults with LNP, and is useful for its diagnosis in this population. The accuracy of this genetic test (GT) has not been completely established in children or in a Latin-American population.The aim of the study was to determine diagnostic accuracy of GT for LNP in Chilean children using the lactose breath test (BT) as a reference, and to compare diagnostic yield in preschool- (6 years) and in school-age (≥6 years) children.Children referred for BT for diagnosis of lactose malabsorption to the Gastroenterology Laboratory at Clínica Alemana, Santiago, from October 2011 to March 2012 were invited to participate. After informed consent, symptom questionnaires, both historic and post lactose ingestion were completed. H2 and CH4 in expired air and -13,910 CT single nucleotide polymorphism by polymerase chain reaction, restriction enzyme analysis, and/or Sanger sequencing were determined. GT accuracy was calculated compared to BT as reference method. Diagnostic yield of GT in preschool- and school-age children was compared.Lactose malabsorption was detected by BT in 42 of 60 children (70%). Genotype -13,910C/C was identified in 41 of 60 patients (68%). GT showed 80% sensitivity, 63% specificity, and 74% accuracy for LNP in the preschool population. In school-age children values were higher, 85%, 80%, and 84%, respectively.GT results were significantly concordant with BT results for hypolactasia detection in Chilean children, particularly in those of age 6 years and older.

Different dietary approaches have been attempted for the treatment of attention-deficit/hyperactivity disorder and autism, but only three of them have been subjected to clinical trials: education in healthy nutritional habits, supplementation and elimination diets. On the other hand, for multiple reasons, the number of people who adopt vegetarian and gluten-free diets (GFD) increases daily. More recently, a new entity, non-celiac gluten sensitivity (NCGS), with a still evolving definition and clinical spectrum, has been described. Although, the benefits of GFD are clearly supported in this condition as well as in celiac disease, in the last two decades, GFD has expanded to a wider population. In this review, we will attempt to clarify, according to the existing evidence, which are the myths and facts of these diets.

Resumen: Introducción: Las últimas guías clínicas conjuntas de NASPGHAN y ESPGHAN en relación a la infección por H. pylori publicadas el año 2016, contienen 20 afirmaciones que han sido cuestionadas en la práctica respecto a su aplicabilidad en Latinoamérica (LA); en particular en relación a la preven ción del cáncer gástrico. Métodos: Se realizó un análisis crítico de la literatura, con especial énfasis en datos de LA y se estableció el nivel de evidencia y nivel de recomendación de las afirmaciones mas controversiales de las Guías Conjuntas. Se realizaron 2 rondas de votación de acuerdo a la técnica Delfi de consenso y se utilizó escala de Likert (de 0 a 4) para establecer el “grado de acuerdo” entre un grupo de expertos de SLAGHNP. Resultados: Existen pocos estudios en relación a diagnóstico, efectividad de tratamiento y susceptibilidad a antibióticos de H. pylori en pacientes pediátricos de LA. En base a estos estudios, extrapolaciones de estudios de adultos y la experiencia clínica del panel de expertos participantes, se realizan las siguientes recomendaciones. Recomendamos la toma de biopsias para test rápido de ureasa e histología (y muestras para cultivo o técnicas moleculares, cuando estén disponibles) durante la endoscopia digestiva alta sólo si en caso de confirmar la infección por H. pylori, se indicará tratamiento de erradicación. Recomendamos que centros regionales seleccio nados realicen estudios de sensibilidad/resistencia antimicrobiana para H. pylori y así actúen como centros de referencia para toda LA. En caso de falla de erradicación de H. pylori con tratamiento de primera línea, recomendamos tratamiento empírico con terapia cuádruple con inhibidor de bomba de protones, amoxicilina, metronidazol y bismuto por 14 días. En caso de falla de erradicación con el esquema de segunda línea, se recomienda indicar un tratamiento individualizado considerando la edad del paciente, el esquema indicado previamente y la sensibilidad antibiótica de la cepa, lo que implica realizar una nueva endoscopía con extracción de muestra para cultivo y antibiograma o es tudio molecular de resistencia. En niños sintomáticos referidos a endoscopía que tengan antecedente de familiar de primer o segundo grado con cáncer gástrico, se recomienda considerar la búsqueda de H. pylori mediante técnica directa durante la endoscopia (y erradicarlo cuando es detectado). Con clusiones: La evidencia apoya mayoritariamente los conceptos generales de las Guías NASPGHAN/ ESPGHAN 2016, pero es necesario adaptarlas a la realidad de LA, con énfasis en el desarrollo de centros regionales para el estudio de sensibilidad a antibióticos y mejorar la correcta selección del tratamiento de erradicación. En niños sintomáticos con antecedente familiar de primer o segundo grado de cáncer gástrico, se debe considerar la búsqueda y erradicación de H. pylori.

Introduction: Compared to bovine formula (BF), breast milk (BM) has unique properties. In the newborn intestine, there is a homeostatic balance between the counterparts of the immune system, which allows a physiological inflammation, modulated by the gut microbiota. Many studies have attempted to understand the effect of BF vs. BM, and the changes in the gut microbiota, but few also focus on intestinal inflammation. Methods: We conducted a cohort study of newborn infants during their first 3 months. In stool samples taken at 1 and 3 months (timepoints T1 and T3), we quantified calprotectin, IL-8 and α1-antitrypsin by ELISA and we evaluated the expression of IL8 and IL1β genes by RT-qPCR. To determine the microbiota composition, the 16S rRNA gene was amplified and sequenced using 454 pyrosequencing. Sequences were clustered into operational taxonomic units (OTUs). Results: In total 15 BM and 10 BF infants were enrolled. In the BM group, we found calprotectin and α1-antitrypsin levels were significantly elevated at T3 compared to T1; no differences were found between T1 and T3 in the BF group. A comparison between the BM and BF groups showed that calprotectin levels at T1 were lower in the BM than the BF group; this difference was not observed at T3. For IL-8 levels, we found no differences between groups. A gene expression analysis of the IL8 and IL1β genes showed that infants from the BF group at T1 have a significantly increased expression of these markers compared to the BM group. Gut microbiota analyses revealed that the phylum Bacteroidetes was higher in BM than BF, whereas Firmicutes were higher in BF. A redundancy analysis and ANOVA showed BM has a community structure statistically different to BF at T1 but not at T3. Compared to BF, BM at T1 showed a higher representation of Enterococcus, Streptococcus, Enterobacter, Lactococcus, and Propionibacterium. Conclusions: We found a basal state of inflammation in the infants' intestine based on inflammation markers. One month after birth, infants receiving BF exhibited higher levels of inflammation compared to BM.

Background Ingested button batteries (BB) can cause corrosive damage of digestive mucosa within minutes. Immediate endoscopic removal of esophageal BB has been clearly established, but the management of BB located in the stomach is still controversial. Aim To describe demographic, clinical, radiologic, and endoscopic characteristics of a series of pediatric patients evaluated for BB ingestion. Methods Retrospective analysis of clinical charts belonging to children younger than 15 years, who underwent endoscopic removal of BB at Clinica Alemana of Santiago, between November 2007 and November 2011. Results Twenty-five patients subjected to upper endoscopy were analyzed; median age, 31 months; 15 were male (60%), and 11 patients (46%) were symptomatic after ingestion. The BB ingestion was confirmed by radiograph. Endoscopy revealed 10 patients with BB in the esophagus, 12 patients in the stomach and 3 distal to duodenum. Range time between ingestion and endoscopy was 2 to 10 hours for esophageal BB and 2 hours to 3 days for gastric BB. Eight of the 22 BBs removed had a diameter of 20 mm or greater, 6 of them were located in the esophagus and 2 in stomach. The BB color changes were observed in 14 of the 22 BBs. Breakage of battery edges was present in 11 of the 22 batteries. All patients with esophageal BB and 6 of those 12 with gastric BB presented mucosal damage. Conclusion Esophageal BB cause damage within hours. The BB located in the stomach may also cause damage early. Extraction of gastric BB before 48 hours should be considered.

Active search of celiac disease (CD) among risk groups has significantly increased the scope of known clinical variants. Aim: To measure the frequency and clinical characteristics of CD among first degree relatives (FDR) of known celiac cases. Material and Methods: Between January 2012-August 2013, 37 patients with celiac disease brought 113 FDR for assessment. Their clinical data was recorded and a blood sample was obtained to measure serum Immunoglobulin A (IgA) levels, anti-transglutaminase (tTG) and anti-endomisial (EMA) antibodies. Cases with positive serology were advised to have an intestinal biopsy. Results: Fourteen relatives (12.4%) had positive serological results and none had IgA deficiency. Among IgA-tTG (-) cases, measurement of IgA/IgG-tTG identified an additional case. Two of the 14 relatives were EMA positive. All 14 cases were advised to have an intestinal biopsy, but only 6 accepted the procedure. In two, the intestinal lesion was classified Marsh ≥ 2 and active CD was diagnosed. Histology in the remaining four was Marsh 0/1 and were diagnosed potential CD, remaining under control, without gluten free diet. Conclusions: Serological prevalence of CD among first degree relatives of known celiac cases was 15 fold greater than in THE general Chilean population, strongly supporting the idea of implementing active search to customary clinical practice. Determination of IgA/IgG-tTG may be useful to improve the yield of active search. Intestinal biopsies were crucial to differentiate active classic CD from potential CD

HLA-linked genes are relevant to celiac disease (CD), the potential genetic differences present worldwide are not fully understood. Previous results suggest that the distribution of HLA-DQ2/DQ7/DQ8 in Chile may differ from that in Europe and North America. In celiac patients and their first-degree relatives (FDRS), we assessed their clinical, serological and histological characteristics, determined HLA-DQ2, HLA-DQ7 and HLA-DQ8 alleles and genotypes, and evaluated the relations between them. A total of 222 individuals were assessed (56 cases, 166 FDRs). 16.9% of FDRs were tTG positive, 53.6% of them showed overweight/obesity and 3% undernourishment, they spontaneously declared being asymptomatic, but detailed questioning revealed that 60.7% experienced symptoms, which had not been investigated. DQ2 was present in 53.9% and 43.9.0% of cases and FDRs (p &lt, 0.05). The most frequent genotype distribution was DQ2/DQ7 (fr 0.392 (cases) and 0.248 (FDRs), respectively, p &lt, 0.02). The next most common genotypes were HLA-DQ2/DQ8 (fr 0.236 in FDRs and 0.176 in cases, p &lt, 0.05). 3.92% cases were not HLA-DQ2/DQ8 carriers. Among tTG positive FDRs, 57.4%, 22.3% and 20.2% carried DQ2, DQ7 and DQ8, respectively. In cases, 72.7% of the biopsies classified Marsh ≥3 carried at least one DQ2, 91.7% of DQ2/DQ2 and 88.3% of DQ2/DQ7 were Marsh ≥3. Thus, DQ2 frequency is lower than reported, the higher frequency found for DQ8 and DQ7 concur with recent publications from Argentine and Brazil. These results suggest that although CD may manifest clinically in ways similar to those described in other populations, some genetic peculiarities in this region deserve further study.

Current reports applying ESPGHAN exception criteria (EEC) to diagnose celiac disease (CD) without duodenal biopsies indicate that a high percentage of patients with CD may be identified when applied correctly in specialized settings. Application of the EEC, however, in "daily life conditions" at the different levels of medical services is not clear.EEC was applied to 130 pediatric patients evaluated for CD at 5 public hospitals in Santiago, Chile, during 2010 to 2015. Clinical presentation, serum anti-tissue transglutaminase 2 and anti-endomysium antibodies (EMA), genotyping, and small intestinal histology were obtained from clinical charts.A total of 78 of 130 patients reviewed had some of the data required for analysis, but EMA was determined in 54% and genotyping in 2.3% of patients, limiting the study. After offering free genotyping, only 12 of 78 (15%) had all data required for EEC application. In this small group, 10 of 12 (83.3%) patients could avoid duodenal biopsies and 2 (16.7%) with potential CD were misdiagnosed. Main reasons for not doing EMA and genotyping were that they are expensive, unavailable in the local health care center, and considered "not necessary" for diagnosis.Limited resources in clinical settings reduce availability of EMA and genotyping, making application of EEC criteria difficult and only possible only in 15% of our patients. Within this subgroup, biopsies could be avoided in 83.3%, and 16.7% of patients with potential CD were misdiagnosed. Insufficient studies and incorrect interpretation of EEC contributed to incomplete assessment in 52 of 130 (40%) patients. The Chilean public health system is likely representative of several others present in developing and developed countries.

Noroviruses (NoVs) are one of the leading causes of acute gastroenteritis, including both outbreaks and endemic infections. The development of preventive strategies, including vaccines, for the most susceptible groups (children

ResumenLa Gastroenteritis Aguda (GEA) infecciosa es una patología frecuente y de alto impacto, especialmente en niños menores de cinco años y adultos mayores. En nuestro medio, la causa más frecuente es viral (rotavirus y norovirus) seguido de Salmonella, Shigella, E.coli diarreogénicas y Campylobacter. Habitualmente son cuadros autolimitados que no requieren estudio de laboratorio específico y cuyo manejo debe centrarse en la reposición hidro-electrolítica de acuerdo al grado de deshidratación. Existe evidencia sobre beneficio sintomático del uso de probióticos (Lactobacillus GG y S.boulardii); racecadotrilo en cuanto a la diarrea; y ondasetrón para los vómitos. En caso de sospecha de agente invasor (bacteria o parásito) debe realizarse un estudio etiológico e iniciar terapia antimicrobiana de acuerdo al microorganismo identificado. La prevención de contagio mediante medidas de saneamiento y adecuada manipulación de agua y alimentos es fundamental. Actualmente se dispone de vacunas efectivas contra algunos de los agentes involucrados (ej. rotavirus), que deben recomendarse en grupos de riesgo.SummaryAcute infectious gastroenteritis (AIGE) is a frequent and high burden disease, especially in children less than five years and elder patients. In Chile, it predominates viral etiology (rotavirus and norovirus), followed by Salmonella, Shigella, diarrheogenic E. coli and Campylobacter. Most of AIGE episodes are self-limited, do not need laboratory workup and their management must be centered on hidroelectrolytic restitution according to dehydration severity. Evidence suggests symptomatic benefit of the use of probiotics (Lactobacillus GG and S. boulardii) and racecadotril for diarrhea and ondasetron for vomits. Etiologic study is indicated whenever an invading agent (bacterium or parasite) is suspected and antimicrobial therapy should be directed against the identified pathogen. Prevention by environmental sanitation measures and appropriate water and food manipulation is crucial for control of AIGE. Currently effective vaccines against some of the agents involved in AIGE (ej. rotavirus) are available and should be recommended in high risk groups.

Rotavirus G8P[8] infection has been common in Africa, but rare in the Americas. Among 23 rotavirus episodes observed during 18 months of surveillance of 100 families in Chile, 11 (48%) were identified as G8P[8]. Genotypes from these strains shared >99% identity with rotavirus sequences described in Asia, and may be misclassified as mixed G8/G12.

ResumenIntroducciónLa adecuada limpieza intestinal (LI) es fundamental para lograr el máximo rendimiento diagnóstico durante una colonoscopia. Existen diversos esquemas de LI, y en pediatría aún no hay consenso respecto al más adecuado.ObjetivoDescribir la efectividad, adherencia y efectos adversos de protocolos de LI diferenciados por edad en pacientes pediátricos sometidos a colonoscopia.Pacientes y métodoEstudio descriptivo que incluyó pacientes

Gluten and other related proteins of the wheat, rye and barley, have antigenic properties that may trigger adverse reactions in susceptible individuals. Celiac disease was the first pathology with clear causal association related to the intake of these proteins. Recently, wheat allergy and non celiac gluten sensitivity have been described. Although, clinical presentation and its relation with protein ingestion may be similar and elicit confusion, their pathogenic mechanism, diagnosis and treatment are quite different. Since the prevalence of these diseases is relatively high as a whole, it is essential that these become familiar to primary care doctors and general pediatricians, thus they will know how to differentiate and face them. The aim of this review is to compare the main aspects of epidemiology, pathofisiology, diagnosis and treatment of these 3 conditions.

Background We previously detected Helicobacter pylori infection by stool antigen ELISA assay in 33-41% of asymptomatic Chilean children between 2–3 years of age, of which 11–20% had a transient infection and 21–22% a persistent infection. A total of 88% of ELISA-positive samples were also rtPCR positive, while 37/133 (33%) of ELISA-negative stool samples were rtPCR positive. The significance of a ELISA-negative/rtPCR-positive sample requires clarification. We aimed to determine whether rtPCR is able to detect persistent infections not detected by ELISA. Materials and Methods We selected 36 children with an ELISA-negative/rtPCR-positive stool sample, of which 25 were never H. pylori infected according to ELISA, and 11 had a transient infection with an ELISA-positive sample before or after the discordant sample. At least two additional consecutive ELISA-negative samples per child were tested in duplicate by rtPCR for the 16s rRNA gene. Results A total of 14 of 78 (17.9%) rtPCR reactions were positive, but only 4/78 (5.1%) were positive in both duplicates, representing a total of 3/36 (8.3%) children with an additional rtPCR-positive sample, only one of whom was persistently negative by ELISA. One child with a transient infection had two positive rtPCR reactions despite negative ELISA samples. Conclusions In H. pylori noninfected or transiently infected children, as determined by stool ELISA, additional ELISA-negative/rtPCR-positive stool samples were found in 8.3% of children, but a possible persistent infection was only identified in 2.7% of children. Thus, the characterization of infection dynamics in children is not being misrepresented by application of stool ELISA. Furthermore, rtPCR does not significantly improve dynamic characterization.

Antecedentes: Rotavirus es la principal causa de gastroenteritis (GE) grave en niños. Actualmente se dispone de dos vacunas con eficacia demostrada contra los genotipos predominantes en el mundo. Los genotipos de rotavirus varían en el tiempo y de una región a otra. Es importante mantener la vigilancia de los genotipos circulantes para monitorizar las tendencias asociadas o no al uso de vacunas. Objetivo: Actualizar la información sobre genotipos de rotavirus circulantes en dos ciudades importantes de Chile (Santiago y Valparaíso). Metodología: Entre mayo 2009 y marzo 2010 se reclutaron niños bajo 5 años de edad con GE atendidos en dos hospitales; ninguno de ellos con historia previa de vacunación anti-rotavirus. Se registró información epidemiológica y se tomó muestra de deposición para detección de rotavirus mediante ELISA comercial. Se realizó genotipificación mediante RPC-TR semi-anidada. Resultados: Se detectó rotavirus en 296/967 muestras analizadas (31%), con un pico de frecuencia en noviembre/diciembre y afectando predominantemente al grupo de 7-24 meses de edad (67%). G9P[8] fue el genotipo predominante (76%), seguido por G1P[8] (6%) y G2P[4] (6%) en ambas ciudades. Conclusiones: Rotavirus causó un tercio de las GE en este grupo, afectando especialmente al grupo de edad que podría beneficiarse con la vacunación anti-rotavirus. G9P[8], una de las variantes contra las cuales las vacunas antirotavirus han demostrado alta eficacia, fue por lejos el genotipo más frecuente. Es necesario continuar la vigilancia en Chile de modo de conocer el impacto de la enfermedad y diversidad de variantes antes de la incorporación de una vacuna anti-rotavirus.

Rotavirus and norovirus are the leading causes of acute gastroenteritis worldwide. Both viruses share features such as low infectious dose, high stool concentration and prolonged survival in the environment, including water. However, they differ in several aspects, reflecting potential differences in their interactive capacities with the environment and host. This work, which is a 13-month prospective study in a developing country with high rotavirus vaccine coverage demonstrated a high (44%) PCR detection of norovirus in 84 wastewater samples compared with a relatively low (11%) detection of rotavirus. These results suggest that rotavirus circulation may be positively affected by vaccination and support the use of enteric viral detection in wastewaters as a useful tool to measure the impact of specific interventions.

Rotarix(®) was first licensed in 2004 and rapidly introduced into private and public markets worldwide. In a previous 2009 article, we reviewed the impact of rotavirus-associated disease, the rationale for different vaccines, prelicensure efficacy studies and cost-effectiveness studies for Rotarix. As of September 2011, Rotarix had been licensed in 123 countries in the Americas, Europe, Australia, Africa and Asia, of which 27 have incorporated the vaccine into national or regional immunization programs. The current review intends to provide the reader with further insight into this vaccine, focusing mainly on the new information obtained after a 6-year postlicensure period. This review will provide only a brief summary of prelicensure studies extensively discussed in the previous publication and refer, in more depth, to the worldwide experience with the vaccine, vaccine impact, and safety observed in effectiveness and observational studies, including a particular analysis on protection against rotavirus G2P[4].

Noroviruses are implicated in many worldwide institutional, food and waterborne outbreaks each year. Genetic typing of isolates is valuable for monitoring outbreak spread as well as variation in circulating strains. Microarrays have the potential to provide rapid genotype information for norovirus samples. The NoroChip v3.0 provides an oligonucleotide hybridization platform to screen for over 600 potential interactions in each experiment. The NoroChip v3.0 was developed at Health Canada and validated in seven international partner laboratories. Each laboratory validated the NoroChip v3.0 using norovirus amplicons routinely characterized in their testing protocols. Fragments from the capsid region (region C) and a 2.4 kb amplicon spanning polymerase and capsid sequences (region AD) were validated in six of the partner laboratories and provided correct genogroup typing information (GI or GII) when hybridized to the NoroChip v3.0. Results indicate that the current limiting factor for implementing the NoroChip v3.0 as a strain typing tool is the difficulty obtaining a long, specific amplicon from all circulating norovirus strains. Data obtained with the longer region AD amplicon provided the best discrimination between norovirus strains.

Background. Noroviruses (NoVs) are the most common cause of viral gastroenteritis. Their high incidence and importance in health care facilities result in a great impact on public health. Studies from around the world describing increasing prevalence have been difficult to compare because of differing nomenclatures for variants of the dominant genotype, GII.4. We studied the global patterns of GII.4 epidemiology in relation to its genetic diversity. Methods. Data from NoV outbreaks with dates of onset from January 2001 through March 2007 were collected from 15 institutions on 5 continents. Partial genome sequences (n = 775) were collected, allowing phylogenetic comparison of data from different countries. Results. The 15 institutions reported 3098 GII.4 outbreaks, 62% of all reported NoV outbreaks. Eight GII.4 variants were identified. Four had a global distribution-the 1996, 2002, 2004, and 2006b variants. The 2003Asia and 2006a variants caused epidemics, but they were geographically limited. Finally, the 2001 Japan and 2001Henry variants were found across the world but at low frequencies. Conclusions. NoV epidemics resulted from the global spread of GII.4 strains that evolved under the influence of population immunity. Lineages show notable (and currently unexplained) differences in geographic prevalence. Establishing a global NoV network by which data on strains with the potential to cause pandemics can be rapidly exchanged may lead to improved prevention and intervention strategies.

Adequate intestinal cleanliness is crucial to achieve optimal colonoscopy performance. Several bowel preparation (BP) schemes have been proposed, but there is still no consensus as regards which is the most suitable in paediatric patients.To describe the effectiveness, adherence, and adverse effects of BP protocols differentiated by age group in paediatric patients subjected to colonoscopy.Prospective, study that included patients18 years subjected to colonoscopy. BP protocols differentiated by age group were indicated as follows:6 m (glycerine suppository); 6 m-3y 11 m (poly-ethylene-glycol (PEG 3350 without electrolytes); 4y-9y 11 m (PEG 3350 without electrolytes + bisacodyl); 10 y-18 y (PEG 3350 with electrolytes). Demographic, clinical information, adherence and adverse effects were registered. Effectiveness was determined using a validated scale (Boston modified) during colonoscopy.A total of 159 patients were included, of which 87 (55%) were males, and with a median age of 4 years (range 1 m-17 years). Seventy eight percent of patients achieved successful BP. The higher effectiveness was observed in the groups of6 m (96%) and 10-18 y (91%). Constipation was significantly more frequent (29%) in the 4 yo-9 yo 11 m in which lower effectiveness was observed (69%). Good adherence was observed in 87% of patients. Adverse effects were observed in a third of patients, although they were mild and did not lead to the suspension of the BP.Satisfactory results were achieved with the BP schemes used, with a successful BP being obtained in 4 out of 5 patients. Results were different between groups, which is probably related to previous bowel transit and indicated medication.

Cow's milk protein allergy (CMPA) is highly prevalent in infants (2-5%). It has a wide clinical spectrum, and confirmation through an oral food challenge (OFC) is relevant for its differential diagnosis. Information on this topic is scarce in Chile.To describe the demographic and clinical features of infants with suspected CMPA.A retrospective study of patients1 year-old, treated for suspected CMPA between 2009 and 2011. Demographic data, symptoms of atopy, nutrition at the time of diagnosis, CMPA symptoms, diagnostic studies, and response to treatment were recorded. Diet response at least 4 weeks after milk modification, and clinical behavior when suspected foods were added back to the diet were considered standard diagnostic criteria. Descriptive statistics were performed using Epiinfo ™ software.The study included 106 infants, of whom, 51% male, 80% term newborns, 74% with≥1 atopic parent, and 34% with ≥1 parent/sibling with food allergy. The median age at onset of symptoms was 1.5 months (range 1.5-2m). Almost half (46%) were breast-feeding≥6m, with 15% receiving formula milk since the neonatal period, and 49% before the third month. Common symptoms were: vomiting (63%), colic (49%), and bleeding on passing stools (41%). No anaphylaxis was identified, and 61% had≥2 symptoms at debut. Only 34% were subjected to OFC. The most frequently requested tests were, test patch (43%), prick test (40%), and blood in stools (37%).43% breast feeding with exclusion diet, 24% extensively hydrolysed formula, 26% amino acid formula, and 7% others.Demographic characteristics and risk factors were similar to those previously described in international literature. Clinical presentation was early in life, and digestive symptoms predominated. OFC was underused for diagnosis, and most of the tests requested did not change management.

Active search of celiac disease (CD) among risk groups has significantly increased the scope of known clinical variants.To measure the frequency and clinical characteristics of CD among first degree relatives (FDR) of known celiac cases.Between January 2012-August 2013, 37 patients with celiac disease brought 113 FDR for assessment. Their clinical data was recorded and a blood sample was obtained to measure serum Immunoglobulin A (IgA) levels, anti-transglutaminase (tTG) and anti-endomisial (EMA) antibodies. Cases with positive serology were advised to have an intestinal biopsy.Fourteen relatives (12.4%) had positive serological results and none had IgA deficiency. Among IgA-tTG (-) cases, measurement of IgA/IgG-tTG identified an additional case. Two of the 14 relatives were EMA positive. All 14 cases were advised to have an intestinal biopsy, but only 6 accepted the procedure. In two, the intestinal lesion was classified Marsh ≥ 2 and active CD was diagnosed. Histology in the remaining four was Marsh 0/1 and were diagnosed potential CD, remaining under control, without gluten free diet.Serological prevalence of CD among first degree relatives of known celiac cases was 15 fold greater than in THE general Chilean population, strongly supporting the idea of implementing active search to customary clinical practice. Determination of IgA/IgG-tTG may be useful to improve the yield of active search. Intestinal biopsies were crucial to differentiate active classic CD from potential CD.

Background Helicobacter pylori, the main cause of peptic ulcer disease and gastric cancer in adult populations, is generally acquired during the first years of life. Infection can be persistent or transient and bacterial and host factors determining persistence are largely unknown and may prove relevant for future disease. Methods Two cohorts of healthy Chilean infants (313 total) were evaluated every 3 months for 18-57 months to determine pathogen- and host-factors associated with persistent and transient infection. Results One-third had at least one positive stool ELISA by age 3, with 20% overall persistence. Persistent infections were acquired at an earlier age, associated with more household members, decreased duration of breastfeeding, and nonsecretor status compared to transient infections. The cagA positive strains were more common in persistent stools, and nearly 60% of fully characterized persistent stool samples amplified cagA/vacAs1m1. Persistent children were more likely to elicit a serologic immune response, and both infection groups had differential gene expression profiles, including genes associated with cancer suppression when compared to healthy controls. Conclusions These results indicate that persistent H. pylori infections acquired early in life are associated with specific host and/or strain profiles possibly associated with future disease occurrence.

Las enfermedades cardiovasculares constituyen un problema relevante como causa de morbimortalidad. Se relacionan con varios factores de riesgo, destacando la hipertensión (HTA) y diabetes (DM2). Estudios extranjeros y nacionales describen una asociación frecuente entre ambos factores. En nuestro país falta información sobre las características clínicas y demográficas de los pacientes portadores de ambas condiciones. Su objetivo es describir el perfil demográfico, clínico y factores de riesgo asociados con HTA y DM2 en un grupo de pacientes atendidos en un consultorio de Los Andes. Se revisaron las fichas de 202 pacientes con HTA y DM2, registrándose: género, edad, año de diagnóstico de HTA, DM2, obesidad y dislipidemia, peso al ingreso y actual, talla, último valor de glicemia, hemoglobina glicosilada A l c, presión arterial y perfil lipídico, tabaquismo, cumplimiento de terapia no farmacológica y fármacos indicados. El 75,7% fueron mujeres y la edad promedio al último control fue 66,6 atlas, siendo el60% mayores de 65 años. Hubo una proporción importante de pacientes con sobrepeso-obesidad (82%) y dislipidemia (88,1%), no así con tabaquismo (12,4%). La proporción de descompensación fue 76,2% para DM2, 80% para HTA y 60,7% tenía ambas patologías no controladas. El93,1% recibía al menos 1 fármaco para tratar su HTA y DM2 y sólo en 50% se registró cumplimiento de las medidas no farmacológicas. La obesidad se relacionó en forma estadísticamente significativa con descompensación tanto de HTA como DM2, mientras que edad < 65 años se asoció a DM2 descompensada. En este grupo, la DM2 e HTA se asociaron frecuentemente a otros factores de riesgo cardiovascular. En los pacientes obesos la tasa de compensación fue menor, lo que sugiere un comportamiento diferente de este grupo. El factor común de estas patologías sería la resistencia a insulina, que requeriría un manejo intensivo e integral desde el punto de vista del síndrome metabólico.