Molecular characterization of rpoB gene mutations in isolates from tuberculosis patients in Cubal, Republic of Angola.

BACKGROUND: The importance of Mycobacterium tuberculosis strains with disputed rpoB mutations remains to be defined. This study aimed to assess the frequency and types of rpoB mutations in M. tuberculosis isolates from Cubal, Angola, a country with a high incidence of tuberculosis. METHODS: All isolates included (n = 308) were analyzed using phenotypic drug susceptibility testing and GenoType MTBDRplus assay. DNA sequencing of the rpoB gene and determination of rifampicin MIC by macrodilution method were additionally performed on isolates yielding discordant results (n = 12) and those in which the mutation detected was not characterized (n = 8). RESULTS: In total, 85.1% (74/87) of rifampicin-resistant strains had undisputed rpoB mutations -S450L (49), D435V (15), H445D (3), H445Y (2), Q432ins (1), L449M plus S450F (1), S450F (1), S450W (1) and S450Y (1)-; 10.3% (9/87) had disputed rpoB mutations-L430P plus S493L (1), N437del (1), H445L (3), D435Y (2), L452P (2)-, 2.3% (2.3%) showed no rpoB mutations and 2.3% (2/87) showed heteroresistance-D435Y plus L452P and L430P plus S493L-. CONCLUSION: Disputed rpoB mutations were common, occurring in 10.3% of rifampicin resistant isolates. Current phenotyping techniques may be unable to detect this resistance pattern. To increase their sensitivity, a lower concentration of RIF could be used in these tests or alternatively, rpoB mutations could be screened and characterized in all M. tuberculosis strains.

Utility of the Cobas® Plasma Separation Card as a Sample Collection Device for Serological and Virological Diagnosis of Hepatitis C Virus Infection.

Diagnosis and clinical management of people infected with hepatitis C virus (HCV) relies on results from a combination of serological and virological tests. The aim of this study was to compare the performance of dried plasma spots (DPS), prepared using the cobas® Plasma Separation Card (PSC), to plasma and serum from venipuncture, for HCV diagnosis. We carried out a prospective study using DPS and paired plasma or serum samples. Serum and DPS samples were analyzed by immunoassay using Elecsys® Anti-HCV II (Roche). Plasma and DPS samples were analyzed using the cobas® HCV viral load and cobas® HCV genotyping tests (Roche). All DPS samples that had high anti-HCV antibody titers in serum were also antibody-positive, as were five of eight samples with moderate titers. Eight samples with low titers in serum were negative with DPS. Among 80 samples with plasma HCV viral loads between 61.5 and 2.2 × 108 IU/mL, 74 were RNA-positive in DPS. The mean viral load difference between plasma and DPS was 2.65 log10 IU/mL. The performance of DPS for detection of serological and virological markers of hepatitis C virus infection was comparable to that of the conventional specimen types. However, the limits of detection were higher for DPS.

T-cell responses as a correlate of COVID-19 vaccination. A pilot study in Health Care Workers.

BackgroundIt is crucial to assess the levels of protection generated by natural infection or SARS-CoV-2 vaccines, mainly in individuals professionally exposed and in vulnerable groups. Measuring T-cell responses may complement antibody tests currently in use as correlates of protection. Our aim was to assess the feasibility of a validated assay of T-cell responses. MethodsTwenty health-care-workers (HCW) were included. Antibody test to SARS-CoV-2 N and S-proteins in parallel with a commercially available whole-blood-interferon-gamma-release-assay (IGRA) to S-peptides and two detection methods, CLIA and ELISA were determined. ResultsIGRA test detected T-cell responses in naturally exposed and vaccinated HCW already after first vaccination dose. The correlation by the two detection methods was very high (R>0.8) and sensitivity and specificity ranged between 100 and 86% and 100-73% respectively. Even though there was a very high concordance between specific antibody levels and the IGRA assay in the ability to detect immune response to SARS-CoV-2, there was a relatively low quantitative correlation. In the small group primed by natural infection, one vaccine dose was sufficient to reach immune response plateau. IGRA was positive in one, with Ig(S) antibody negative vaccinated immunosuppressed HCW illustrating another advantage of the IGRA-test. ConclusionWhole-blood-IGRA-tests amenable to automation and constitutes a promising additional tool for measuring the state of the immune response to SARS-CoV-2; they are applicable to large number of samples and may become a valuable correlate of protection to COVID-19, particularly for vulnerable groups at risk of being re-exposed to infection, as are health-care-workers.

Actualización en Endodoncia 2013 / 2013 Update in Endodontics

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2013, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia

The authors review the articles published in the most relevant journals concerning endodontics during the last year 2013, making a comparison between them, as well as with other older ones and with classic concepts in endodontics

Sealapex Xpress and RealSeal XT feature tissue compatibility in vivo.

OBJECTIVE: This study evaluated the response of apical and periapical tissues of dogs' teeth with pulp vitality after root canal filling with the endodontic sealers Sealapex Xpress and Real Seal XT. METHODS: Thirty-eight root canals with vital pulp from dogs' premolars were used. After instrumentation, the canals were filled with Sealapex Xpress and gutta-percha (group SX/GP, n = 16) or Real Seal XT and Resilon cones (group RS/R, n = 22). The animals were killed after 90 days, and the teeth with surrounding tissues were subjected to histotechnical processing. Hematoxylin-eosin-stained sections were examined by conventional light microscopy for a quantitative histopathologic analysis (sealing of apical opening by newly formed mineralized tissue [biological sealing], inflammatory cell infiltrate, root and bone tissue resorption), according to a scoring system. The subsequent sections were evaluated by immunohistochemistry for identification of mineralization markers (osteopontin, alkaline phosphatase, and RUNX2). Data were analyzed by nonparametric Mann-Whitney U test (α = 0.05). RESULTS: Complete biological sealing was observed in 50% and 22.7% of the specimens of groups SX/GP and RS/R, respectively. Partial biological sealing was observed in 25% and 54.6% and absence of sealing in 25% and 22.7% of the specimens of groups SX/GP and RS/R, respectively. There were no significant differences (P > .05) between the groups for the scores attributed to the histopathologic parameters. Positive staining for osteopontin, alkaline phosphatase, and RUNX2 was observed in both groups, especially in the periodontal ligament. CONCLUSIONS: Sealapex Xpress and RealSeal XT feature tissue compatibility in vivo and allow for sealing of apical opening by deposition of mineralized tissue.

Gripe 2014 / Flu 2014

No disponible

Diagnóstico microbiológico de las infecciones virales respiratorias en el paciente adulto / Microbiological diagnosis of viral respiratory infections in the adult patient

Las técnicas tradicionales para el diagnóstico de los virus respiratorios siguen estando todavía vigentes, aunque los métodos moleculares aplicados al diagnóstico de la infección viral respiratoria han supuesto una auténtica revolución. Las técnicas moleculares tienen como principales ventajas una excelente sensibilidad, especificidad, capacidad de adaptación a virus emergentes, capacidad para detectar múltiples dianas en un mismo ensayo y posibilidad de automatización. Adicionalmente, estas técnicas han permitido profundizar en el papel de los virus en la infección respiratoria aguda a la vez que han descrito la existencia de nuevos virus no conocidos previamente. Los métodos moleculares y no moleculares de diagnóstico rápido para 1 o más virus respiratorios han permitido la toma de decisiones de forma inmediata en el manejo del paciente mejorando su pronóstico y evitando la transmisión nosocomial. Sin embargo, también hay inconvenientes, la mayor sensibilidad de las técnicas moleculares ha supuesto un incremento significativo de la tasa de codetecciones múltiples de virus respiratorios, cuya implicación clínica resulta difícil de interpretar. Finalmente queda por demostrar todavía si la utilización de las nuevas técnicas, de elevado coste, en el diagnóstico microbiológico de rutina de las infecciones respiratorias agudas de etiología viral, en el paciente hospitalizado, es coste-efectiva

Conventional techniques for the diagnosis of respiratory viruses are still being used, although molecular methods are now considered as a gold standard in this field. Molecular techniques have a great number of advantages such as an excellent sensitivity, specificity, adaptability to emerging viruses, capability for multiplex and for automation. With all the available repertoire of techniques for microbiological diagnosis, the knowledge relative to respiratory viruses is growing up not only for new aetiological agents but also for its epidemiology. The advances in molecular and non-molecular fast diagnostic methods for one or more respiratory viruses allow quick decisions in the management of the patient. However, there are also disadvantages. The great sensitivity of molecular techniques has meant a significant increase in the rate of multiple detections of respiratory viruses, whose clinical involvement is difficult to interpret. Finally, it remains to show whether the use of new techniques, of high cost, in the microbiological routine diagnosis of acute respiratory viral infections in the hospitalized patient, is cost effective

Diagnóstico microbiológico de las infecciones virales respiratorias en el paciente adulto / Microbiological diagnosis of viral respiratory infections in the adult patient

Las técnicas tradicionales para el diagnóstico de los virus respiratorios siguen estando todavía vigentes, aunque los métodos moleculares aplicados al diagnóstico de la infección viral respiratoria han supuesto una auténtica revolución. Las técnicas moleculares tienen como principales ventajas una excelente sensibilidad, especificidad, capacidad de adaptación a virus emergentes, capacidad para detectar múltiples dianas en un mismo ensayo y posibilidad de automatización. Adicionalmente, estas técnicas han permitido profundizar en el papel de los virus en la infección respiratoria aguda a la vez que han descrito la existencia de nuevos virus no conocidos previamente. Los métodos moleculares y no moleculares de diagnóstico rápido para 1 o más virus respiratorios han permitido la toma de decisiones de forma inmediata en el manejo del paciente mejorando su pronóstico y evitando la transmisión nosocomial. Sin embargo, también hay inconvenientes, la mayor sensibilidad de las técnicas moleculares ha supuesto un incremento significativo de la tasa de codetecciones múltiples de virus respiratorios, cuya implicación clínica resulta difícil de interpretar. Finalmente queda por demostrar todavía si la utilización de las nuevas técnicas, de elevado coste, en el diagnóstico microbiológico de rutina de las infecciones respiratorias agudas de etiología viral, en el paciente hospitalizado, es coste-efectiva (AU)

Conventional techniques for the diagnosis of respiratory viruses are still being used, although molecular methods are now considered as a gold standard in this field. Molecular techniques have a great number of advantages such as an excellent sensitivity, specificity, adaptability to emerging viruses, capability for multiplex and for automation. With all the available repertoire of techniques for microbiological diagnosis, the knowledge relative to respiratory viruses is growing up not only for new aetiological agents but also for its epidemiology. The advances in molecular and non-molecular fast diagnostic methods for one or more respiratory viruses allow quick decisions in the management of the patient. However, there are also disadvantages. The great sensitivity of molecular techniques has meant a significant increase in the rate of multiple detections of respiratory viruses, whose clinical involvement is difficult to interpret. Finally, it remains to show whether the use of new techniques, of high cost, in the microbiological routine diagnosis of acute respiratory viral infections in the hospitalized patient, is cost effective (AU)

Actualización en endodoncia 2012 / 2012 Update in endodontics

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2012, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the articles published in the most relevant journals concerning endodontics during the last year 2012, making a comparison between them, as well as with other older ones and with classic concepts in endodontics (AU)

Actualización en endodoncia 2011 / 2011 Update in endodontics

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2011, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the articles published in the most relevant journals concerning endodontics during the last year 2011, making a comparison between them, as well as with other older ones and with classic concepts in endodontics (AU)

Actualización en endodoncia 2010 / 2010 Update in Endodontics

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2010, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the articles published in the most relevant journals concerning endodontics during the last year 2010, making a comparison between them, as well as with other older one and with classic concepts in endodontics (AU)

La nueva gripe A (H1N1) 2009 en Atención Primaria: ¿qué nos hemos encontrado? / New influenza A (H1N1) 2009 in Primary Care: what have we found?

Objetivo: describir las características clínicas de los casos de gripe pandémica A (H1N1) 2009 diagnosticados por pediatras centinela del programa PIDIRAC (Programa de información diaria de las infecciones respiratorias agudas de Catalunya) en atención primaria (AP). Material y métodos: la muestra de estudio estaba formada por los casos visitados por cuatro de los pediatras centinela que participan en el programa PIDIRAC. Se recogieron de forma sistemática, para evitar sesgo de muestreo, muestras faríngeas y nasales de los casos sospechosos de gripe para su estudio virológico. Cada semana del periodo de estudio se seleccionaron los dos primeros pacientes que acudieron a la consulta y cumplían con los criterios de caso sospechoso, se recogieron sus datos demográficos y clínicos y se cursó el estudio viral. A los 55 niños con gripe pandémica A (H1N1) 2009 se les realizó un seguimiento telefónico para conocer la evolución del cuadro. Resultados: la mayor parte de los casos tenían una edad entre cinco y 14 años (89,1%; intervalo de confianza del 95% [IC 95%]: 77,8-95,9). Los síntomas más frecuentes fueron la fiebre (criterio de inclusión), que duró una media de 3,6 días (desviación estándar [DE]: 1,6) y la tos. Más de la mitad refirieron también odinofagia, rinitis o cefalea. En general, el cuadro clínico fue leve, aunque un niño fue ingresado durante 48 horas por presentar una neumonía. De los 13 niños que tenían antecedentes de asma, dos presentaron exacerbaciones leves. Ningún niño recibió tratamiento antiviral. Conclusión: a pesar de los temores iniciales, los casos de gripe pandémica A (H1N1) 2009 en los niños atendidos en nuestras consultas de AP han sido generalmente leves (AU)

Objective: to describe the clinical features of pandemic influenza cases diagnosed in primary health care by sentinel pediatricians who participate in the PIDIRAC surveillance scheme (Programa de información diaria de las infecciones respiratorias agudas de Catalunya). Methods: study sample included the cases of confirmed influenza A (H1N1) 2009 attended by sentinel pediatricians that collaborate with PIDIRAC. Pharyngeal and nasopharyngeal swabs for virologic analysis of suspected influenza cases were collected on a systematic basis in order to avoid bias. Every week during the study period the first two patients that consult and comply with the definition of suspicious case of influenza were recruited, if consent was obtained. Demographic characteristics and clinical features were recorded, and virologic studies were performed. The fifty-five children with confirmed pandemic influenza A (H1N1) 2009 were contacted by telephone in order to obtain information regarding their clinical status. Results: most of the cases were 5-14 years old children and adolescents (89.1%, 95% CI 77.8-95.9). The most frequent symptoms were fever (inclusion criteria), that lasted a mean of 3.6 days (SD = 1.6) and cough. More than 50% of patients also presented with sore throw, rhinitis or headache. In general, the disease was mild even though one child was hospitalised during 48 hours because he (or she) had a pneumonia. Of the thirteen patients who suffered from asthma only two had mild exacerbations. None of the patients needed antiviral treatment. Conclusions: despite initial fears, the cases of pandemic influenza A (H1N1) 2009 treated in our community health centres have been generally mild (AU)

Actualización en endododoncia 2008 / 2008 Update in endodontics

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2008, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the article published in the most relevant journals concerning endodontics during the last year 2008, making a comparison between them, as well as with other older ones and with classic conepts in endodontics (AU)

Actualización en Endodoncia 2007 / 2007 Update in Endodontics

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2007 comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the articles published in the most relevant journals concerning endodontic during the last year 2007, making a comparison between them as well as with other older ones and with classic concepts in endodontics (AU)

Estudio comparativo de la preparación de los conductos radiculares con diversos sistemas de instrumentación mecánico-rotatoria / No disponible

Objetivo: el objetivo de este estudio fue evaluar la deformación longitudinal en conductos curvos artificiales instrumentados con las limas mecánico-rotatorias de niquel titanio HERO Shaper y RaCe, determinar el calibre y conicidad de la lima maestra apical, así como la primera lima que inició la deformación. Material y métodos: Un total de 20 conductos curvos artificiales fueron distribuidos aleatoriamente en dos grupos de 10 cada uno. Se prepararon los conductos utilizando la técnica crown-down. Se superpusieron las imágenes obtenidas mediante observación estéreo-microscópica de un mismo conducto radicular antes y después de su instrumentación. Se mantuvieron la posición y los aumentos en las observaciones realizadas con todas las muestras utilizadas en este estudio. Los datos obtenidos fueron analizados utilizando el test de Kruskal Wallis y el test de la U de Mann Whitney. Resultados: Se prepararon los cubiletes del grupo RaCe con una secuencia menor de limas. La preparación del tercio coronal, con ambos sistemas, fue homogénea amentando la deformación en el tercio medio y parte del tercio apical. La deformación en la preparación de los últimos dos milímetros fue menor con la límas RaCe que con las de HERO Shaper. La primera lima que inició la deformación con RaCe fue de igual conicidad y de calibre mayor que HERO Shaper. Conclusiones: Bajo las condiciones de este estudio RaCe mantuvo mejor la curvatura original del conducto artificial que HERO Shaper (AU)

Objective: The aim of this study was to evaluate the longitudinal transportation of artifically curved canals instrumetne with two Rotary Niti systems (HERO Shaper and RaCe), as well as to determine the size and the taper of the apical master file, and the size and taper of the first file which started the transportation. Methodology: 20 artificially curved canals ( plastic blocks) were prepared, and divided into 2 groups of 10: group HS (prepared with HERO files) and group RC (prepared with RaCe files). The canals were instrumented according to the crown-down technique. Pre-op and post-op pictures of the same canals were superposed for a stereoscopic observation. All samples of this study were examined under the same conditions: position and image magnification. The results were analyzed according to the Kruskel Wallis and Mant Whitney LL test. Results: The plastic blocks of the RaCe group were instrumented in a shorter sequence. No difference was observed in the preparation of the coronal third between the systems. However the transportation increased in the middle and apical thirds. The first RaCe file that started trasportation was of the same taper but of a larger diameter than the HERO Shaper. Conclusions: According to our study, RaCe respected the original curvature of the artificial canal better than HERO Shaper (AU)

Actualización en endodoncia 2006 / No disponible

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2006, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the articles published in the most relevant journals concerning endodontics during the last year 2006, making a comparison between them, as well other older ones and with classic concepts in endodontics (AU)

Estudio con microscopio electrónico del barrido del smear layer residual después de la instrumentación de conductos radiculares con distintos instrumentos rotatorios (AU) / No disponible

Objetivo: Se evaluó comparativamente la presencia de smear layer residual tras la instrumentación de conductos con dos sistemas de instrumentación diferentes; uno con apoyos radiales: ProFile y otro sin ellos: RaCe. Metodología: Se seleccionaron 15 conductos de molares extraídos y se distribuyeron aleatoriamente en tres grupos de 5 cada uno (grupo PP: motor eléctrico de una velocidad de 300 r.p.m. y un torque dinámico AP-10. En los tres grupos, la irrigación entre cada instrumento se realizó alternando 2 ml de NaOCI (5,25%) y 2 ml de ác. Cítrico 820%9. La limpieza de las paredes de los conductos se estudió con Microscopia electrónica de barrido utilizando 5 categorías para cuantificar la cantidad de smear layer a 1000 aumentos. El análisis estadístico de los resultados se realizó con el test de Kruskal-Walls y la U de Mann-Whitney (...) (AU)

Aim: Compare the smear layer left on canal walls after rool cannal instrumentation with two different systems: one with radial lands - Profile and another without radial lands - RaCe. Methodology: 15 molar root canals were divided into 3 groups of 5. Group PF; Profile, group Rc: RaCe, group RCSA: RaCe and S-Apex. there were all run in a 1:18 WH reducing contra-angle on an electric motor, at a 300 rpm speed and AP-10 dynamic lorque. For all groups, irrigation was performed alternating 2 ml NaOCU (at 5,25%) and 2 ml citric acid (at 20%) after each instrument. Cleaning of canal walls was observed under SEM at a 1000x magnification, using a 1 to 5 scale to quantify the amount of semera layer left. Satitiscial analysis of the results was made using the Kruskal Walls and Mann-Whitney U test (...)(AU)

[Clinical and epidemiological characteristics of influenza A virus infection in children aged less than 7 years old in primary care]. / Aspectos clínico-epidemiológicos de la infección por virus de la gripe A en menores de 7 años en atención primaria.

INTRODUCTION: The aim of this study was to describe the clinical and epidemiological features of confirmed influenza A virus infection in patients aged less than 7 years old. PATIENTS AND METHODS: We performed a retrospective, descriptive study of the clinical and epidemiological features of influenza A virus infection in patients aged less than 7 years old attending three primary care centers during the 2003-2004 influenza season. Patients with influenza A infection confirmed by immunofluorescence, cell culture, or polymerase chain reaction were interviewed to obtain clinical and epidemiological data on their disease. RESULTS: Influenza A virus was detected in 47 patients aged between 5 months and 7 years (mean: 37.3 +/- 5.7 months). Of these, 35 children (74.4 %) were aged between 0 and 4 years. The most frequent symptoms were fever (100 %), cough (95.7 %), and rhinorrhea (76.6 %). Gastrointestinal symptoms were present in 40.4 % of the patients. The mean duration of fever was 5.2 +/- 1.8 days (range 2-8). Complications occurred in nine patients (19.2 %). The frequency of influenza-like disease in parents was 9.1 % (8/88) at diagnosis of the index case and was 23.9 % (21/88) immediately after the episode in the child (p 5 0.01). The mean number of days of absence from school was 7.5 +/- 3.6 days. CONCLUSIONS: The mean age of our patients confirms that influenza is a frequent disease in infancy and childhood. The results demonstrate that the infection is transmitted from children to parents in the household setting, since the frequency of influenza-like symptoms in adults increases after influenza episodes in children.

Aspectos clínico-epidemiológicos de la infección por virus de la gripe A en menores de 7 años en atención primaria / Clinical and epidemiological characteristics of influenza A virus infectionin children aged less than 7 years old in primary care

Introducción El objetivo del estudio ha sido analizar aspectos clínicos y epidemiológicos en pacientes menores de 7 años con enfermedad confirmada por virus de la gripe A. Pacientes y métodos Estudio descriptivo retrospectivo sobre clínica y epidemiología de la infección por el virus de la gripe A en pacientes menores de 7 años, atendidos en 3 centros de atención primaria, durante la temporada gripal 2003-2004. Los pacientes con infección confirmada por inmunofluorescencia, cultivo celular o reacción en cadena de la polimerasa, fueron entrevistados para obtener la información clínico-epidemiológica. Resultados El virus de la gripe A se detectó en 47 pacientes de 5 meses a 6 años y 11 meses (media 37,3 6 5,7 meses). El 74,4 % (35/47) menor de 4 años. La fiebre (100 %), tos (95,7 %) y rinorrea (76,6 %) fueron los síntomas más frecuentes; la sintomatología gastrointestinal estuvo presente en el 40,4 % de los niños. La duración media de la fiebre fue de 5,2 6 1,8 días (rango 2-8). Se presentaron complicaciones en el 19,2 % (9/47). La frecuencia de síndromes gripales en los padres fue del 9,1 % (8/88) en el momento del diagnóstico de la gripe al caso índice y de 23,9 % (21/88) inmediatamente después de la enfermedad del niño (p 5 0,01). Los días de ausencia escolar fueron 7,5 6 3,6 días. Conclusiones La media de edad de nuestros pacientes confirma que la gripe es una enfermedad frecuente en lactantes y niños pequeños. Los resultados demuestran que en el entorno doméstico la infección se transmite de niños a padres, ya que la frecuencia de síndromes gripales en adultos aumenta tras la enfermedad del niño

Introduction The aim of this study was to describe the clinical and epidemiological features of confirmed influenza A virus infection in patients aged less than 7 years old. Patients and methods We performed a retrospective, descriptive study of the clinical and epidemiological features of influenza A virus infection in patients aged less than 7 years old attending three primary care centers during the 2003-2004 influenza season. Patients with influenza A infection confirmed by immunofluorescence, cell culture, or polymerase chain reaction were interviewed to obtain clinical and epidemiological data on their disease. Results Influenza A virus was detected in 47 patients aged between 5 months and 7 years (mean: 37.3 6 5.7 months). Of these, 35 children (74.4 %) were aged between 0 and 4 years. The most frequent symptoms were fever (100 %), cough (95.7 %), and rhinorrhea (76.6 %). Gastrointestinal symptoms were present in 40.4 % of the patients. The mean duration of fever was 5.2 6 1.8 days (range 2-8). Complications occurred in nine patients (19.2 %). The frequency of influenza-like disease in parents was 9.1 % (8/88) at diagnosis of the index case and was 23.9 % (21/88) immediately after the episode in the child (p 5 0.01). The mean number of days of absence from school was 7.5 6 3.6 days. Conclusions The mean age of our patients confirms that influenza is a frequent disease in infancy and childhood. The results demonstrate that the infection is transmitted from children to parents in the household setting, since the frequency of influenza-like symptoms in adults increases after influenza episodes in children