Effect of Helicobacter pylori eradication therapy on clinical and laboratory biomarkers associated with gastric damage in healthy school-aged children: A randomized non-blinded trial.

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 < .001). Treatment was associated with mild transient symptoms (altered taste, nocturnal upper abdominal pain, nausea, and diarrhea). Baseline frequency of symptoms was low and eradication did not change symptoms compared to controls. PGI, PGII, and anti-H. pylori seropositivity were similar in both groups at baseline and significantly decreased only in eradicated patients; PGI (92.5 vs. 74.4, p < .001), PGII (15.2 vs. 8.9, p < .001) levels, and frequency of anti-H. pylori seropositivity (100 vs. 68%, p < .001) respectively. Four eradicated children (13%) were reinfected during follow-up. CONCLUSIONS: H. pylori eradication therapy in apparently asymptomatic school-aged children was well tolerated and associated with decreased serum PGI and PGII levels. Future studies should expand on the middle-long-term effect of early H. pylori eradication, especially on preventing gastric cancer.

Helicobacter pylori, clinical, laboratory, and noninvasive biomarkers suggestive of gastric damage in healthy school-aged children: A case-control study.

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 < 0.001); no difference was observed in other biomarkers or gene expression profiles. CONCLUSIONS: H. pylori infection in apparently asymptomatic school-aged children is associated with an increase in clinical symptoms and in the level of one significant biomarker, pepsinogen II, suggesting early gastric involvement.

Norovirus compared to other relevant etiologies of acute gastroenteritis among families from a semirural county in Chile.

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 <24 months of age were followed for 1-2 years to detect any AGE. Stool samples were tested for viral and bacterial pathogens and a questionnaire was completed for those with norovirus or rotavirus AGE. RESULTS: Between April and June 2016, 110 families were enrolled, with 103 of them completing ≥12 months of follow-up. A total of 159 family AGE episodes were detected, mostly affecting one individual (92%). At least one pathogen was detected in 56% (94/169) of samples, of which 75/94 (80%) were sole infections. Norovirus was most common (n=26), followed closely by enteropathogenic Escherichia coli (EPEC) (n=25), rotavirus (n=24), and astrovirus (n=23). The annual incidence of family AGE was 0.77, and 0.12 for norovirus. Most norovirus AGE occurred in children <4 years old (96%). Only 13/159 (8%) index AGE cases resulted in a secondary case, of which four were associated with norovirus. The majority of norovirus strains were GII (85%), with a mild predominance of GII.4 (9/26; 35%); most norovirus isolates (69%) were recombinants. CONCLUSIONS: The family incidence of AGE in this lower middle income community was nearly one episode per year, mostly caused by viruses, specifically norovirus closely followed by rotavirus and astrovirus. Norovirus infections primarily affected children <4 years old and secondary cases were uncommon.

Predominance of Rotavirus G8P[8] in a City in Chile, a Country Without Rotavirus Vaccination.

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.

Helicobacter pylori Infection Is Associated with Decreased Expression of SLC5A8, a Cancer Suppressor Gene, in Young Children.

Background:Helicobacter pylori infects half of the world's population and causes gastric cancer in a subset of infected adults. Previous blood microarray findings showed that apparently healthy children, persistently infected with H. pylori have differential gene expression compared to age-matched, non-infected children. SLC5A8, a cancer suppressor gene with decreased expression among infected children, was chosen for further study based on bioinformatics analysis. Methods: A pilot study was conducted using specific qRT-PCR amplification of SLC5A8 in blood samples from H. pylori infected and non-infected children, followed by a larger, blinded, case-control study. We then analyzed gastric tissue from H. pylori infected and non-infected children undergoing endoscopy for clinical purposes. Results: Demographics, clinical findings, and family history were similar between groups. SLC5A8 expression was decreased in infected vs. non-infected children in blood, 0.12 (IQR: 0-0.89) vs. 1.86 (IQR: 0-8.94, P = 0.002), and in gastric tissue, 0.08 (IQR: 0.04-0.15) vs. 1.88 (IQR: 0.55-2.56; P = 0.001). Children who were both stool positive and seropositive for H. pylori had the lowest SLC5A8 expression levels. Conclusions:H. pylori infection is associated with suppression of SCL5A8, a cancer suppressor gene, in both blood and tissue samples from young children. Key Points: Young children, persistently infected with Helicobacter pylori show decreased expression of SLC5A8 mRNA in both blood and tissue samples as compared to non-infected children.

[Detection of human bocavirus in children from Tucuman and Santa Fe, Argentina]. / Detección de bocavirus humano en la población infantil de Tucumán y Santa Fe, Argentina.

BACKGROUND: A large proportion of acute respiratory tract infections (ARTI) remain without etiologic diagnosis, reason why new pathogens are investigated continuously. Human bocavirus (HBoV) was discovered in 2005, as a new member of Parvoviridae family and proposed to cause ARTI. AIM: To know the prevalence of HBoV among pediatric populations hospitalized for ARTI in two provinces of Argentina: Santa Fe and Tucuman; and to describe epidemiological and clinical aspects associated to its detection. MATERIALS AND METHODS: We studied nasopharyn-geal aspirates of patients younger than 5 years old that were hospitalized during 2013 due ARTI. HBoV DNA was assayed using PCR described by Allander et al. Traditional virnses were studied by immunofluorescence. Personal, clinical and epidemiological data were collected in a standardized form. RESULTS: The HBoV was detected in 7% of the samples and was prevalent in spring and summer and in children younger of 2 years old. Other respiratory viruses were detected in 22% of HBoV positive samples. DISCUSSION: We detected HBoV in these two provinces of Argentina. Further studies should be performed to determine if it's a recent infection or prolonged viral shedding.

Rotavirus Serum IgA Immune Response in Children Receiving Rotarix Coadministered With bOPV or IPV.

BACKGROUND: Vaccine schedules including bivalent oral and inactivated poliovirus vaccines will replace trivalent oral poliovirus vaccines in 2016. METHODS: We evaluated rotavirus immunoglobulin A seroresponses when the second dose of Rotarix at 16 weeks was given concomitantly with inactivated or bivalent oral poliovirus vaccines. RESULTS: Rotavirus immunoglobulin A seroresponse rate at week 28 was 15% lower in recipients of bivalent oral poliovirus vaccines compared with inactivated poliovirus vaccines. CONCLUSION: Bivalent oral poliovirus vaccine decreases rotavirus IgA seroresponse rates when coadministered at 16 weeks of age.

Detection of Helicobacter pylori by Real-Time PCR for 16s rRNA in Stools of NonInfected Healthy Children, Using ELISA Antigen Stool Test as the Gold Standard.

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.

Detección de bocavirus humano en la población infantil de Tucumán y Santa Fe, Argentina / Detection of human bocavirus in children from Tucuman and Santa Fe, Argentina

Background: A large proportion of acute respiratory tract infections (ARTI) remain without etiologic diagnosis, reason why new pathogens are investigated continuously. Human bocavirus (HBoV) was discovered in 2005, as a new member of Parvoviridae family and proposed to cause ARTI. Aim: To know the prevalence of HBoV among pediatric populations hospitalized for ARTI in two provinces of Argentina: Santa Fe and Tucuman; and to describe epidemiological and clinical aspects associated to its detection. Materials and Methods: We studied nasopharyn-geal aspirates of patients younger than 5 years old that were hospitalized during 2013 due ARTI. HBoV DNA was assayed using PCR described by Allander et al. Traditional virnses were studied by immunofluorescence. Personal, clinical and epidemiological data were collected in a standardized form. Results: The HBoV was detected in 7% of the samples and was prevalent in spring and summer and in children younger of 2 years old. Other respiratory viruses were detected in 22% of HBoV positive samples. Discussion: We detected HBoV in these two provinces of Argentina. Further studies should be performed to determine if it’s a recent infection or prolonged viral shedding.

Introducción: Un alto porcentaje de las infecciones respiratorias agudas (IRA) permanece sin diagnostico etiológico, por lo cual se investigan nuevos patógenos continuamente. Bocavirus humano (HBoV) fue descubierto en 2005, como un nuevo miembro de la familia Parvoviridae y propuesto como causante de IRA. Objetivos: Investigar la prevalencia de HBoV en niños bajo 5 años de edad, hospitalizados por IRA en dos provincias de Argentina: Santa Fe y Tucumán y describir aspectos epidemiológicos y clínicos asociados a su detección. Materiales y Métodos: Se estudiaron retrospectivamente los aspirados nasofaríngeos (ANF) de pacientes bajo 5 años de edad, con diagnóstico de IRA, hospitalizados durante el año 2013. La presencia de HBoV se detectó mediante la RPC de punto final descripta por Allander y cols. Los virus tradicionales se estudiaron mediante inmunofluorescencia. Datos personales, clínicos y epidemiológicos se recolectaron en una planilla estandarizada. Resultados: HBoV fue detectado en 7% de las muestras con prevalencia en primavera y verano; y principalmente en pacientes bajo 2 años de edad. Se registró co-detecciones en 22% de los casos. Discusión: Hemos detectado HBoV en estas dos provincias de Argentina; estudios posteriores deberán efectuarse para determinar si se trata de una infección reciente o una excreción prolongada del virus.

Persistent and transient Helicobacter pylori infections in early childhood.

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.

[Latent tuberculosis infection screening in healthcare workers in four large hospitals in Santiago, Chile]. / Pesquisa de infección tuberculosa latente en personal de la salud en cuatro instituciones de salud en Santiago de Chile.

BACKGROUND: It is currently unknown which is the prevalence of latent tuberculosis infection in healthcare workers in Chile, but this group has been described as at higher risk of developing active tuberculosis than general population. OBJECTIVES: To determine the prevalence of latent tuberculosis infection in a sample of healthcare workers from at risk areas. METHODOLOGY: A cross-sectional, descriptive study, conducted in health care workers from clinical laboratories or respiratory care areas in four hospitals in Santiago. Latent tuberculosis infection detection was determined by Quantiferon® TB Gold In Tube testing (QFT). RESULTS: QFT resulted positive in 20 of 76 (26.3%) of the individuals tested. Test positivity reached 62.5% among the personnel that reported history of past TB contact in the community, 50% among the personnel who belonged to the national tuberculosis control program and 38% among those doing induced sputum, acid fast smear or mycobacterial cultures. The proportion of individuals with positive QFT was significantly lower in those personnel who had no such risk factors (15.7%, p = 0.03). The proportion of latent tuberculosis infection also increased in direct relation to the age of the subject. CONCLUSION: Latent tuberculosis infection as detected by QFT testing was highly prevalent in healthcare workers included in the present study. Further exploring the limitations and possible scenarios for this new diagnostic tool is needed, with emphasis on health personnel at higher-risk and younger individuals.

Pesquisa de infección tuberculosa latente en personal de la salud en cuatro instituciones de salud en Santiago de Chile / Latent tuberculosis infection screening in healthcare workers in four large hospitals in Santiago, Chile

Background: It is currently unknown which is the prevalence of latent tuberculosis infection in healthcare workers in Chile, but this group has been described as at higher risk of developing active tuberculosis than general population. Objectives: To determine the prevalence of latent tuberculosis infection in a sample of healthcare workers from at risk areas. Methodology: A cross-sectional, descriptive study, conducted in health care workers from clinical laboratories or respiratory care areas in four hospitals in Santiago. Latent tuberculosis infection detection was determined by Quantiferon® TB Gold In Tube testing (QFT). Results: QFT resulted positive in 20 of 76 (26.3%) of the individuals tested. Test positivity reached 62.5% among the personnel that reported history of past TB contact in the community, 50% among the personnel who belonged to the national tuberculosis control program and 38% among those doing induced sputum, acid fast smear or mycobacterial cultures. The proportion of individuals with positive QFT was significantly lower in those personnel who had no such risk factors (15.7%, p = 0.03). The proportion of latent tuberculosis infection also increased in direct relation to the age of the subject. Conclusion: Latent tuberculosis infection as detected by QFT testing was highly prevalent in healthcare workers included in the present study. Further exploring the limitations and possible scenarios for this new diagnostic tool is needed, with emphasis on health personnel at higher-risk and younger individuals.

Introducción: Se desconoce en la actualidad cuál es la real prevalencia de infección tuberculosa latente en el personal de salud en Chile; sin embargo, este grupo ha sido descrito como con mayor riesgo de desarrollar tuberculosis activa que la población general. Objetivo: Determinar la prevalencia de infección tuberculosa latente en funcionarios de la salud en diferentes áreas laborales de riesgo. Metodología: Estudio de corte transversal, descriptivo, realizado en funcionarios pertenecientes a laboratorios clínicos o áreas de atención broncopulmonar de cuatro hospitales de la Región Metropolitana en quienes se hizo test de Quantiferon TB Gold®In tube(QFT). Resultados: Se evidenció infección tuberculosa latente en 20 de las 76 (26,3%) personas estudiadas. En aquellos funcionarios que referían antecedente de contacto en el pasado en la comunidad con enfermos de tuberculosis, la positividad del test llegó a 62,5%; en aquellos que pertenecían al Programa Nacional de Control de la Tuberculosis, a 50% y en los que realizaban toma de esputo inducido, baciloscopias o cultivo de micobacterias, a 38%. La proporción de individuos con QFT positivo fue significativamente menor en aquellos funcionarios que no tenían estos antecedentes (15,7%, p = 0,03). Se encontró además una mayor proporción de infección tuberculosa latente a mayor edad del individuo estudiado. Conclusión: La infección tuberculosa latente medida por QFT resultó altamente prevalente en el personal de la salud incluido en el presente estudio. Es necesario seguir profundizando en los posibles escenarios de implementación y limitaciones del uso de esta nueva herramienta diagnóstica, haciendo énfasis en el personal de la salud de mayor riesgo y menor edad.

[Rotavirus genotypes in children with gastroenteritis assisted in two public hospitals from Chile: viral strains circulating in a country without a universal vaccination against rotavirus]. / Genotipos de rotavirus aislados de niños chilenos con gastroenteritis atendidos en dos hospitales públicos: variantes virales circulantes en un país con uso limitado de vacunas anti-rotavirus.

BACKGROUND: Rotavirus is the main cause of severe gastroenteritis (GE) in children. Two vaccines currently available have proven efficacy against the predominant genotypes. Rotavirus genotypes vary both geographically and/or temporally. Genotype surveillance is important to monitor trends associated or not with vaccine use. AIM: To update information on rotavirus genotypes circulating in two main cities of Chile. METHODOLOGY: Between May 2009-March 2010, children < 5y of age receiving medical care for GE in two large hospitals were recruited; none of these children had received rotavirus vaccine previously. Epidemiological information was recorded in an ad-hoc form and stool samples were collected for rotavirus detection by a commercial ELISA. Genotyping was performed by semi-nested RT-PCR. RESULTS: A total of 296/967 samples (31%) were positive for rotavirus, with a peak in November/ December mostly in children 7-24 months old (67%). G9P[8] was the predominant genotype (76%), followed for G1P[8] (6%) and G2P[4] (6%) in both cities. CONCLUSIONS: Rotavirus caused one third of GE requiring emergency room care and/or hospitalization, mostly in children within an age range susceptible to benefit from rotavirus vaccines. G9P[8], a genotype against which rotavirus vaccines have demonstrated high efficacy, was by far the most frequent rotavirus variant. Continued surveillance in Chile is crucial for providing background information on disease burden and strain diversity before the introduction of rotavirus vaccines.

Genotipos de rotavirus aislados de niños chilenos con gastroenteritis atendidos en dos hospitales públicos: variantes virales circulantes en un país con uso limitado de vacunas anti-rotavirus / Rotavirus genotypes in children with gastroenteritis assisted in two public hospitals from Chile: viral strains circulating in a country without a universal vaccination against rotavirus

Background: Rotavirus is the main cause of severe gastroenteritis (GE) in children. Two vaccines currently available have proven efficacy against the predominant genotypes. Rotavirus genotypes vary both geographically and/or temporally. Genotype surveillance is important to monitor trends associated or not with vaccine use. Aim: To update information on rotavirus genotypes circulating in two main cities of Chile. Methodology: Between May 2009-March 2010, children < 5y of age receiving medical care for GE in two large hospitals were recruited; none of these children had received rotavirus vaccine previously. Epidemiological information was recorded in an ad-hoc form and stool samples were collected for rotavirus detection by a commercial ELISA. Genotyping was performed by semi-nested RT-PCR. Results: A total of 296/967 samples (31%) were positive for rotavirus, with a peak in November/ December mostly in children 7-24 months old (67%). G9P[8] was the predominant genotype (76%), followed for G1P[8] (6%) and G2P[4] (6%) in both cities. Conclusions: Rotavirus caused one third of GE requiring emergency room care and/or hospitalization, mostly in children within an age range susceptible to benefit from rotavirus vaccines. G9P[8], a genotype against which rotavirus vaccines have demonstrated high efficacy, was by far the most frequent rotavirus variant. Continued surveillance in Chile is crucial for providing background information on disease burden and strain diversity before the introduction of rotavirus vaccines.

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.

A third gyrovirus species in human faeces.

Until 2011 the genus Gyrovirus in the family Circoviridae consisted of a single virus (Chicken anemia virus or CAV) causing a common immunosuppressive disease in chickens when a second gyrovirus (HGyV) was reported on the skin of 4 % of healthy humans. HGyV is very closely related to a recently described chicken gyrovirus, AGV2, suggesting that they belong to the same viral species. During a viral metagenomic analysis of 100 human faeces from children with diarrhoea in Chile we identified multiple known human pathogens (adenoviruses, enteroviruses, astroviruses, sapoviruses, noroviruses, parechoviruses and rotaviruses) and a novel gyrovirus species we named GyV3 sharing <63 % similarity with other gyrovirus proteins with evidence of recombination with CAV in its UTR. Gyroviridae consensus PCR revealed a high prevalence of CAV DNA in diarrhoea and normal faeces from Chilean children and faeces of USA cats and dogs, which may reflect consumption of CAV-infected/vaccinated chickens. Whether GyV3 can infect humans and/or chickens requires further studies.

Prospective characterization of norovirus compared with rotavirus acute diarrhea episodes in chilean children.

BACKGROUND: Rotavirus and more recently noroviruses are recognized as main causes of moderate to severe acute diarrhea episodes (ADE) in children < or =5 years of age. Comparing epidemiologic and clinical features of norovirus to rotavirus ADE will aid in the decision-making process required to develop norovirus vaccines. METHODS: Surveillance for ADE occurring in children < or =5 years of age was implemented in the emergency department (ED) and ward of a large hospital in Santiago and Valparaiso, and in 4 outpatient clinics in Santiago. A stool sample was obtained within 48 hours of consultation for rotavirus detection by enzyme-linked immunosorbent assay and noroviruses by enzyme-linked immunosorbent assay or reverse transcription polymerase chain reaction. For ED and hospital rotavirus and norovirus ADE parents were instructed to monitor clinical findings associated with severity until the end of the episode. The 20-point Vesikari score was used to determine disease severity. RESULTS: Between July 2006 and October 2008 rotavirus and noroviruses were detected in 331 (26%) and 224 (18%) of 1913 ADE evaluated. The proportion of rotavirus-positive samples in hospital ward, ED, and outpatient clinic was 40%, 26% to 30%, and 13% compared with 18%, 17% to 19%, and 14% for noroviruses. Mean age and 25%-75% interquartile interval of children with rotavirus and norovirus ADE were remarkably similar, 15.6 months (9-20), and 15.5 months (9-19), respectively. Rotavirus cases displayed an autumn-winter peak followed 2 to 3 months later by the norovirus peak. The mean (interquartile) for the Vesikari score was 12.9 (11-15) and 11.9 (9-14.5) for rotavirus (N = 331) and norovirus (N = 224) ADE, respectively, P = 0.003. Compared with norovirus, rotavirus ADE were more common in the 11 to 16 severity score interval (P = 0.006), had a higher maximum stool output in a given day (P = 0.01) and more frequent fever (P < 0.0001). Duration of diarrhea, presence, duration and intensity of vomiting, and intensity of fever did not differ between viruses. Mixed rotavirus and norovirus infections were uncommon (<1%) and not clinically more severe. Clinical severity of ADE in young infants was similar for rotavirus and lower (P = 0.03) for noroviruses compared with older children. CONCLUSION: Noroviruses are a significant cause of moderate to severe endemic ADE in Chilean children. Although significantly less severe than rotavirus as a group, most norovirus episodes were moderate to severe clinically. An effective norovirus vaccine would be of significant additional benefit to the current rotavirus vaccine in decreasing disease burden associated with ADE.

Symptomatic and asymptomatic rotavirus and norovirus infections during infancy in a Chilean birth cohort.

BACKGROUND: Rotavirus and more recently norovirus have been recognized as 2 of the most common causes of acute diarrhea in children. Comparative analysis of these infections in a birth cohort has not been performed and can provide relevant insight on clinical and viral behaviors. METHODS: Mother-infant pairs from middle-low socioeconomic background living in the Metropolitan Region of Chile are being followed for 18 months in 2 outpatient clinics. Infants are evaluated monthly for asymptomatic excretion of rotavirus and norovirus and during acute diarrhea episodes (ADE) for rotavirus, norovirus, and bacterial enteropathogens. Severity of ADE is evaluated using the Vesikari score. RESULTS: Between July 1, 2006 and September 1, 2008 a total of 198 children were followed for a mean of 15.7 months. Asymptomatic rotavirus and norovirus infections were detected in 1.3% and 8% of 2278 stool samples compromising 14% and 57% of infants, respectively. Incidence of ADE was approximately 0.8 for the first year of life and approximately 0.6 for the 13 to 18 month age group. Rotavirus and norovirus were detected in 15% and 18% of 145 ADE evaluated. Mean Vesikari score was 10.4 and 7.4 for rotavirus and norovirus respectively (P = 0.01) and severity was not associated with age of patients for either virus. Reinfections were more common for norovirus asymptomatic episodes: 44% versus 19% (P = 0.01) and borderline for symptomatic episodes: 40% versus 11% (P = 0.08). Rotavirus genotype G9P8 and norovirus genogroup II (GII) predominated although most asymptomatic episodes for both viruses were nontypable. None of 19 symptomatic GII norovirus infections had a previous documented GII infection compared with 10 of 31 asymptomatic GII infections (OR = 0. 95% CL = 0, 0.59; P = 0.008). CONCLUSIONS: Children had suffered a mean of approximately 1.4 ADE by 18 months of age of which 15% and 18% were caused by rotavirus and norovirus, respectively. In general rotavirus infections were more severe than norovirus infections and for both viruses severity was not related to age. Norovirus reinfections were significantly more common than rotavirus reinfections but for GII norovirus a primary infection seems to confer protection against clinically significant reinfections.

Impact of rotavirus infections on outpatient clinic visits in chile.

BACKGROUND: Incorporation of new rotavirus vaccines into national programs of developing countries will rely on well-designed cost-effective analysis based on accurate assessment of disease burden. For Chile, rotavirus disease burden is determined mostly by outpatient clinic and emergency room visits and by hospitalizations. We previously estimated a yearly incidence of 8000 and 53,000 hospitalizations and emergency room visits respectively for children

Novel recombinant norovirus causing outbreaks of gastroenteritis in Santiago, Chile.

Capsid and polymerase (RdRp) genes of 13 norovirus outbreak strains from Chile were compared. The genes sequences were discordant for five strains, and recombination was confirmed for two of them by amplification of a 1,360-bp gene segment containing a fragment of both genes. These strains belonged to a novel genogroup by RdRp sequence and to genogroup GII/3 by capsid sequence. Determining the clinical and epidemiological impact of human calicivirus recombination will require future studies.