Role for Maternal Asthma in Severe Human Metapneumovirus Lung Disease Susceptibility in Children.

BACKGROUND: Severity of human metapneumovirus (hMPV) lower respiratory illness (LRTI) is considered similar to that observed for respiratory syncytial virus (RSV). However, differences in severity between these pathogens have been noted, suggesting the degree of illness may vary in different populations. Moreover, a potential association between hMPV and asthma also suggests that hMPV may preferentially affect asthmatic subjects. METHODS: In a population-based surveillance study in children aged <2 years admitted for severe LRTI in Argentina, nasopharyngeal aspirates were tested by RT-PCR for hMPV, RSV, influenza A, and human rhinovirus. RESULTS: Of 3947 children, 383 (10%) were infected with hMPV. The hospitalization rate for hMPV LRTI was 2.26 per 1000 children (95% confidence interval [CI], 2.04-2.49). Thirty-nine (10.2%) patients infected with hMPV experienced life-threatening disease (LTD; 0.23 per 1000 children; 95% CI, .16-.31/1000), and 2 died (mortality rate 0.024 per 1000; 95% CI, .003-.086). In hMPV-infected children birth to an asthmatic mother was an increased risk for LTD (odds ratio, 4.72; 95% CI, 1.39-16.01). We observed a specific interaction between maternal asthma and hMPV infection affecting risk for LTD. CONCLUSIONS: Maternal asthma increases the risk for LTD in children <2 years old hospitalized for severe hMPV LRTI.

Respiratory Failure and Death in Vulnerable Premature Children With Lower Respiratory Tract Illness.

BACKGROUND: Efforts to better understand the risk factors associated with respiratory failure (RF) and fatal lower respiratory tract infection (LRTI) in premature children in developing countries are necessary to elaborate evidenced-based preventive interventions. We aim to characterize the burden of respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) LRTI in premature children and determine risk factors for RF and fatal illness in a vulnerable population. METHODS: This is a prospective, population-based, cross-sectional study. Subjects with severe LRTI were enrolled during respiratory season. Risk factors for RF and death in premature infants were investigated. RESULTS: A total of 664 premature children participated. Infant's hospitalization rate due to LRTI was 82.6/1000 (95% confidence interval [CI], 68.6-96.7/1000). Infant's RSV and hMPV rates were 40.9/1000 (95% CI, 36.3-45.6/1000) and 6.6/1000 (95% CI, 3.9-9.2/1000), respectively. The RF rate was 8.2/1000 (95% CI, 4.9-11.5/1000). The LRTI mortality was 2.2/1000 (95% CI, 0.7-3.7/1000); for RSV, the rate was 0.8/1000 (95% CI, 0-1.7/1000) with a case-fatality ratio of 1.8%. Never breastfeeding, malnutrition, younger than 6 months, congenital heart disease, and lower hematocrit were risk factors for RF. Experiencing pneumonia, pneumothorax, sepsis, or apnea were clinical determinants of poor outcomes. CONCLUSIONS: Premature children under 2 years old in vulnerable environments experience RF and death more often than term counterparts. Modifiable risk factors associated with poor outcomes should prompt evidence-based interventions.

Impacto clínico-epidemiológico del virus sincicial respiratorio e identificación de factores de riesgo de enfermedad grave en niños hospitalizados por infección respiratoria aguda / Clinical and epidemiological impact of respiratory syncytial virus and identification of risk factors for severe disease in children hospitalized due to acute respiratory tract infection

Introducción: La infección respiratoria aguda grave (IRA) es una causa muy frecuente de internación en pediatría; el virus sincicial respiratorio (VSR) es el principal agente etnológico. Definir en forma precisa la carga de enfermedad que compromete la vida (ECV) por este virus y los factores de riesgo es un desafío. Objetivos: Conocer el impacto del VSR en internados por IRA y describir factores de riesgo de ECV. Materiales y métodos: Estudio prospectivo en niños < 2 años internados por IRA durante 20122013 en el Hospital de Niños "R. Gutiérrez". Se definió ECV el requerimiento de ventilación no invasiva y/o asistencia respiratoria mecánica. Resultados: 622 niños estudiados, 372 VSR (+) (el 59,8 %). Tasa de hospitalización anual por VSR en < 1 año: 956 (IC 95 %: 858-1062)/10 000 internaciones. El VSR causó 56/78 (el 71,8 %) casos de ECV; 42 (el 75 %) eran previamente sanos; 32 (el 76,2 %) tenían < 6 meses de edad. En el análisis multivariado, el VSR fue un factor de riesgo de ECV (odds ratio ajustado --#91;ORa--#93; 2,04; IC 95 %: 1,15-3,63; p = 0,014). Se identificó un efecto diferencial según género en pacientes VSR (+): el hacinamiento fue un factor de riesgo de ECV en varones (ORa 2,36; IC 95 %: 1,07-5,21; p = 0,033); la lactancia materna protegió significativamente a las niñas (ORa 0,342; IC 95 %: 0,13-0,91; p = 0,032). Conclusiones: El VSR causó más de la mitad de los casos de IRA y afectó, en su mayoría, a pacientes < 1 año previamente sanos. Los varones en condiciones de hacinamiento y las niñas que no recibieron leche materna constituyeron el grupo con mayor riesgo de ECV.

Introduction: Severe acute respiratory tract infection (ARTI) is a very common cause of hospitalization in pediatrics; respiratory syncytial virus (RSV) is the major etiologic agent. Accurately defining the burden of RSV life-threatening disease (LTD) and its risk factors is a challenge. Objectives: To know the impact of RSV in children hospitalized due to ARTI and describe the risk factors for LTD. Materials and methods: Prospective study in children < 2 years old hospitalized due to ARTI during 2012-2013 at Hospital de Niños "R. Gutiérrez." LTD was defined as requiring non-invasive ventilation and/or mechanical ventilation. Results: 622 studied children, 372 were RSV(+) (59.8 %). Annual rate of hospitalization due to RSV in infants < 1 year old: 956 (95 % CI: 858-1062)/10 000hospitalizations. RSV caused 56/78 (71.8 %) cases of LTD; 42 (75 %) were previously healthy subjects; 32 (76.2 %) were < 6 months old. In the multivariate analysis, RSV was a risk factor for LTD (adjusted odds ratio --#91;aOR--#93;: 2.04; 95 % CI: 1.15-3.63; p = 0.014). A differential effect by sex was identified in RSV(+) patients: over-crowding was a risk factor for LTD in males (aOR: 2.36; 95 % CI: 1.07-5.21; p = 0.033); breastfeeding was a significant protective factor in females (aOR: 0.342; 95 % CI: 0.13-0.91; p = 0.032). Conclusions: RSV caused more than half of ARTI cases and mostly affected previously healthy patients < 1 year old. Males living in overcrowding conditions and females who were not breastfed were at the greatest risk for LTD.

Clinical and epidemiological impact of respiratory syncytial virus and identification of risk factors for severe disease in children hospitalized due to acute respiratory tract infection. / Impacto clínico-epidemiológico del virus sincicial respiratorio e identificación de factores de riesgo de enfermedad grave en niños hospitalizados por infección respiratoria aguda.

INTRODUCTION: Severe acute respiratory tract infection (ARTI) is a very common cause of hospitalization in pediatrics; respiratory syncytial virus (RSV) is the major etiologic agent. Accurately defining the burden of RSV life-threatening disease (LTD) and its risk factors is a challenge. OBJECTIVES: To know the impact of RSV in children hospitalized due to ARTI and describe the risk factors for LTD. MATERIALS AND METHODS: Prospective study in children < 2 years old hospitalized due to ARTI during 2012-2013 at Hospital de Niños "R. Gutiérrez." LTD was defined as requiring non-invasive ventilation and/or mechanical ventilation. RESULTS: 622 studied children, 372 were RSV(+) (59.8 %). Annual rate of hospitalization due to RSV in infants < 1 year old: 956 (95 % CI: 858-1062)/10 000hospitalizations. RSV caused 56/78 (71.8 %) cases of LTD; 42 (75 %) were previously healthy subjects; 32 (76.2 %) were < 6 months old. In the multivariate analysis, RSV was a risk factor for LTD (adjusted odds ratio [aOR]: 2.04; 95 % CI: 1.15-3.63; p = 0.014). A differential effect by sex was identified in RSV(+) patients: over-crowding was a risk factor for LTD in males (aOR: 2.36; 95 % CI: 1.07-5.21; p = 0.033); breastfeeding was a significant protective factor in females (aOR: 0.342; 95 % CI: 0.13-0.91; p = 0.032). CONCLUSIONS: RSV caused more than half of ARTI cases and mostly affected previously healthy patients < 1 year old. Males living in overcrowding conditions and females who were not breastfed were at the greatest risk for LTD.

Introducción: La infección respiratoria aguda grave (IRA) es una causa muy frecuente de internación en pediatría; el virus sincicial respiratorio (VSR) es el principal agente etnológico. Definir en forma precisa la carga de enfermedad que compromete la vida (ECV) por este virus y los factores de riesgo es un desafío. Objetivos: Conocer el impacto del VSR en internados por IRA y describir factores de riesgo de ECV. Materiales y métodos: Estudio prospectivo en niños < 2 años internados por IRA durante 20122013 en el Hospital de Niños "R. Gutiérrez". Se definió ECV el requerimiento de ventilación no invasiva y/o asistencia respiratoria mecánica. Resultados: 622 niños estudiados, 372 VSR (+) (el 59,8 %). Tasa de hospitalización anual por VSR en < 1 año: 956 (IC 95 %: 858-1062)/10 000 internaciones. El VSR causó 56/78 (el 71,8 %) casos de ECV; 42 (el 75 %) eran previamente sanos; 32 (el 76,2 %) tenían < 6 meses de edad. En el análisis multivariado, el VSR fue un factor de riesgo de ECV (odds ratio ajustado [ORa] 2,04; IC 95 %: 1,15-3,63; p = 0,014). Se identificó un efecto diferencial según género en pacientes VSR (+): el hacinamiento fue un factor de riesgo de ECV en varones (ORa 2,36; IC 95 %: 1,07-5,21; p = 0,033); la lactancia materna protegió significativamente a las niñas (ORa 0,342; IC 95 %: 0,13-0,91; p = 0,032). Conclusiones: El VSR causó más de la mitad de los casos de IRA y afectó, en su mayoría, a pacientes < 1 año previamente sanos. Los varones en condiciones de hacinamiento y las niñas que no recibieron leche materna constituyeron el grupo con mayor riesgo de ECV.

Impacto clínico y epidemiológico de las infecciones por varicela en niños previo a la introducción de la vacuna al Calendario Nacional de Argentina / Clinical and epidemiological impact of varicella infection in children prior to the introduction of the varicella vaccine in the national immunization schedule of Argentina

Introducción. En Argentina, se estiman 400 000 casos anuales de varicela. Dado el subregistro de casos existentes, la carga de enfermedad real se desconoce. Objetivo. Evaluar la carga de enfermedad por varicela antes de la introducción de la vacuna al Calendario Nacional. Materiales y métodos. Estudio retrospectivo, analítico, observacional, realizado en tres centros asistenciales del país. Revisión de los registros de consultas ambulatorias a los Servicios de Urgencias y de las historias clínicas de las internaciones por varicela en pacientes < 18 años. Período: 1/2011-12/2013. Resultados. Fueron asistidas un total de 382782 consultas ambulatorias; 3367 (0,88 %) correspondieron a consultas por varicela; el 57,6 %, < 4 años. Requirieron internación 164 (4,9 %) con una tasa de hospitalización global de 65,3/10000 hospitalizados/año (IC 95 %: 55,4-76,5); tasa de hospitalización en niños sanos: 57,2/10 000 (IC 95 %: 67,7-48,0); mediana de edad: 31,5 meses. Las causas de internación más frecuentes fueron infecciones de piel y/o partes blandas (61,1 %) y respiratorias (10,1 %). El 54,3 % recibió tratamiento con aciclovir, y el 73,1 %, con antibióticos. Presentaron bacteriemia 5/67 (7,5 %), todas por cocos Gram(+) y en inmunocompetentes. De los 19 pacientes inmunocomprometidos, el 36,8 % tuvo complicaciones (5 infecciones de piel y/o partes blandas y 2 neumonías). La mediana de días de internación fue 4, significativamente más prolongada en pacientes inmunocomprometidos. Un paciente requirió cuidados intensivos. No hubo fallecidos. Conclusión. La carga de enfermedad registrada fue significativa, con impacto considerable en pacientes sin patología de base.

Introduction. In Argentina, an estimated 400 000 varicella cases occur annually. Given the under-recording of existing cases, the actual burden of disease is unknown. Objective. To assess the burden of varicella before the introduction of the varicella vaccine in the national immunization schedule. Materials and methods. Retrospective, analytical, observational study carried out in three hospitals of Argentina. Review of medical records from outpatient visits to the Emergency Department and from patients younger than 18 years hospitalized for varicella. Period: 1/2011-12/2013. Results. A total of 382 782 outpatients were seen; 3367(0.88%) corresponded to visits due to varicella; 57.6 % were < 4 years old. A total of 164 (4.9 %) patients required hospitalization, with an overall hospitalization rate of 65.3/10 000 hospitalized patients/year (95 % confidence interval -#91;CI-#93;: 55.4-76.5); hospitalization rate in healthy children: 57.2/10 000 (95 % CI: 67.7-48.0); median age: 31.5 months. The most common causes of hospitalization were skin and/or soft tissue infections (61.1 %) and respiratory infections (10.1 %). Also, 54.3 % were treated with acyclovir and 73.1 %, with antibiotics. Bacteremia developed in 5/67 patients (7.5 %), all cases were caused by Gram-positive cocci and occurred in immunocompetent patients. Out of 19 immunocompromised patients, 36.8 % had complications (5 skin and/or soft tissue infection and 2 pneumonia cases). The median length of stay was 4 days, which is significantly more prolonged in immunocompromised patients. One patient required intensive care. No patient died. Conclusion. The burden of disease was significant, with a considerable impact in patients without an underlying disease.

Brote epidémico de dengue en la Ciudad de Buenos Aires, 2016: características clínicas y hematológicas de la infección en una población pediátrica / Dengue outbreak in Buenos Aires, Argentina, 2016: Clinical and hematological features in children

El dengue es la arbovirosis humana que más morbimortalidad ocasiona mundialmente. Durante 2016, se registró, en la Ciudad de Buenos Aires, Argentina, la mayor epidemia de esta enfermedad. Objetivo: describir las características clínicas y hematológicas en una población pediátrica. Métodos: estudio de corte transversal que incluyó a pacientes atendidos del 18-1-16 al 15-4-16 en el Hospital de Niños "Dr. Ricardo Gutiérrez". Resultados: se registraron 156 casos, 82 confirmados por virología; 130 (83 %), autóctonos. Las manifestaciones clínicas más frecuentes fueron fiebre, cefalea y dolor retroocular. Las alteraciones del laboratorio significativas fueron leucopenia, plaquetopenia y aumento de transaminasas. Se internaron 35 pacientes (23 %), 25 (16 %) con signos de alarma. No se presentó ningún caso de dengue grave. Conclusiones: el reconocimiento oportuno de los signos de alarma y el control hematológico resultan fundamentales para detectar a los niños en riesgo y ofrecerles tratamiento de soporte en forma precoz.

Dengue is the human arbovirus with the highest morbidity and mortality in the world. The largest outbreak of dengue in Buenos Aires, Argentina, occurred during 2016. Objective: To describe clinical and hematological features in children with confirmed dengue infection. Methods: Cross sectional study that included children attended since January 18th to April 15th 2016 at Hospital de Niños "Dr. Ricardo Gutiérrez". Results: among 156 registered cases, 82 confirmed cases by virology test; 130 (83 %) autochthonous cases. The most frequent clinical manifestations were fever, headache and retro-ocular pain. Laboratory abnormalities were leukopenia, thrombocytopenia and increased liver enzymes. Thirty-five children were hospitalized (23 %), 25 (16 %) with warning signs. In our study, no cases of severe dengue occurred. Conclusions: early recognition of warning signs and hematological monitoring is essential in order to detect patients at risk and offer them adequate early treatment.

Clinical and epidemiological impact of varicella infection in children prior to the introduction of the varicella vaccine in the national immunization schedule of Argentina. / Impacto clínico y epidemiológico de las infecciones por varicela en niños previo a la introducción de la vacuna al Calendario Nacional de Argentina.

INTRODUCTION: In Argentina, an estimated 400 000 varicella cases occur annually. Given the under-recording of existing cases, the actual burden of disease is unknown. OBJECTIVE: To assess the burden of varicella before the introduction of the varicella vaccine in the national immunization schedule. MATERIALS AND METHODS: Retrospective, analytical, observational study carried out in three hospitals of Argentina. Review of medical records from outpatient visits to the Emergency Department and from patients younger than 18 years hospitalized for varicella. Period: 1/2011-12/2013. RESULTS: A total of 382 782 outpatients were seen; 3367(0.88%) corresponded to visits due to varicella; 57.6 % were < 4 years old. A total of 164 (4.9 %) patients required hospitalization, with an overall hospitalization rate of 65.3/10 000 hospitalized patients/year (95 % confidence interval |#91;CI|#93;: 55.4-76.5); hospitalization rate in healthy children: 57.2/10 000 (95 % CI: 67.7-48.0); median age: 31.5 months. The most common causes of hospitalization were skin and/or soft tissue infections (61.1 %) and respiratory infections (10.1 %). Also, 54.3 % were treated with acyclovir and 73.1 %, with antibiotics. Bacteremia developed in 5/67 patients (7.5 %), all cases were caused by Gram-positive cocci and occurred in immunocompetent patients. Out of 19 immunocompromised patients, 36.8 % had complications (5 skin and/or soft tissue infection and 2 pneumonia cases). The median length of stay was 4 days, which is significantly more prolonged in immunocompromised patients. One patient required intensive care. No patient died. CONCLUSION: The burden of disease was significant, with a considerable impact in patients without an underlying disease.

Introducción. En Argentina, se estiman 400 000 casos anuales de varicela. Dado el subregistro de casos existentes, la carga de enfermedad real se desconoce. Objetivo. Evaluar la carga de enfermedad por varicela antes de la introducción de la vacuna al Calendario Nacional. Materiales y métodos. Estudio retrospectivo, analítico, observacional, realizado en tres centros asistenciales del país. Revisión de los registros de consultas ambulatorias a los Servicios de Urgencias y de las historias clínicas de las internaciones por varicela en pacientes < 18 años. Período: 1/2011-12/2013. Resultados. Fueron asistidas un total de 382782 consultas ambulatorias; 3367 (0,88 %) correspondieron a consultas por varicela; el 57,6 %, < 4 años. Requirieron internación 164 (4,9 %) con una tasa de hospitalización global de 65,3/10000 hospitalizados/año (IC 95 %: 55,4-76,5); tasa de hospitalización en niños sanos: 57,2/10 000 (IC 95 %: 67,7-48,0); mediana de edad: 31,5 meses. Las causas de internación más frecuentes fueron infecciones de piel y/o partes blandas (61,1 %) y respiratorias (10,1 %). El 54,3 % recibió tratamiento con aciclovir, y el 73,1 %, con antibióticos. Presentaron bacteriemia 5/67 (7,5 %), todas por cocos Gram(+) y en inmunocompetentes. De los 19 pacientes inmunocomprometidos, el 36,8 % tuvo complicaciones (5 infecciones de piel y/o partes blandas y 2 neumonías). La mediana de días de internación fue 4, significativamente más prolongada en pacientes inmunocomprometidos. Un paciente requirió cuidados intensivos. No hubo fallecidos. Conclusión. La carga de enfermedad registrada fue significativa, con impacto considerable en pacientes sin patología de base.

[Dengue outbreak in Buenos Aires, Argentina, 2016: Clinical and hematological features in children]. / Brote epidémico de dengue en la Ciudad de Buenos Aires, 2016: características clínicas y hematológicas de la infección en una población pediátrica.

Dengue is the human arbovirus with the highest morbidity and mortality in the world. The largest outbreak of dengue in Buenos Aires, Argentina, occurred during 2016. OBJECTIVE: To describe clinical and hematological features in children with confirmed dengue infection. METHODS: Cross sectional study that included children attended since January 18th to April 15th 2016 at Hospital de Niños "Dr. Ricardo Gutiérrez". RESULTS: among 156 registered cases, 82 confirmed cases by virology test; 130 (83 %) autochthonous cases. The most frequent clinical manifestations were fever, headache and retro-ocular pain. Laboratory abnormalities were leukopenia, thrombocytopenia and increased liver enzymes. Thirty-five children were hospitalized (23 %), 25 (16 %) with warning signs. In our study, no cases of severe dengue occurred. CONCLUSIONS: early recognition of warning signs and hematological monitoring is essential in order to detect patients at risk and offer them adequate early treatment.

El dengue es la arbovirosis humana que más morbimortalidad ocasiona mundialmente. Durante 2016, se registró, en la Ciudad de Buenos Aires, Argentina, la mayor epidemia de esta enfermedad. Objetivo: describir las características clínicas y hematológicas en una población pediátrica. Métodos: estudio de corte transversal que incluyó a pacientes atendidos del 18-1-16 al 15-4-16 en el Hospital de Niños "Dr. Ricardo Gutiérrez". Resultados: se registraron 156 casos, 82 confirmados por virología; 130 (83 %), autóctonos. Las manifestaciones clínicas más frecuentes fueron fiebre, cefalea y dolor retroocular. Las alteraciones del laboratorio significativas fueron leucopenia, plaquetopenia y aumento de transaminasas. Se internaron 35 pacientes (23 %), 25 (16 %) con signos de alarma. No se presentó ningún caso de dengue grave. Conclusiones: el reconocimiento oportuno de los signos de alarma y el control hematológico resultan fundamentales para detectar a los niños en riesgo y ofrecerles tratamiento de soporte en forma precoz.

Alcohol during pregnancy worsens acute respiratory infections in children.

AIM: This study explored whether alcohol consumption during pregnancy increased the risk of life-threatening respiratory infections in children. METHODS: We prospectively evaluated children under the age of two years admitted to hospitals in Buenos Aires, Argentina, with severe acute respiratory infections during the winters of 2011 and 2012. Information on maternal alcohol consumption during the third trimester of pregnancy was collected using standardised questionnaires and categorised as never, low if it was once a week and high if it was equal or more than once a week. RESULTS: Of the 3423 children hospitalised with acute respiratory infection, 2089 (63.7%) had respiratory syncytial virus (RSV). Alcohol consumption during the last trimester was reported by 398 mothers (12.4%) and categorised as low (n = 210, 6.5%) or high (n = 188, 5.9%). A greater effect on life-threatening respiratory infection, defined as oxygen saturation of or up to 87%, was observed with higher alcohol intake due to all viruses and specifically RSV in the logistic regression analyses. Alcohol consumption was strongly associated with life-threatening disease, particularly in boys whose adjusted odds ratio rose from 3.67 to 13.52 when their mothers drank alcohol. CONCLUSION: Alcohol consumption during pregnancy was associated with life-threatening respiratory infections in boys.

TLR4 genotype and environmental LPS mediate RSV bronchiolitis through Th2 polarization.

While 30%-70% of RSV-infected infants develop bronchiolitis, 2% require hospitalization. It is not clear why disease severity differs among healthy, full-term infants; however, virus titers, inflammation, and Th2 bias are proposed explanations. While TLR4 is associated with these disease phenotypes, the role of this receptor in respiratory syncytial virus (RSV) pathogenesis is controversial. Here, we evaluated the interaction between TLR4 and environmental factors in RSV disease and defined the immune mediators associated with severe illness. Two independent populations of infants with RSV bronchiolitis revealed that the severity of RSV infection is determined by the TLR4 genotype of the individual and by environmental exposure to LPS. RSV-infected infants with severe disease exhibited a high GATA3/T-bet ratio, which manifested as a high IL-4/IFN-γ ratio in respiratory secretions. The IL-4/IFN-γ ratio present in infants with severe RSV is indicative of Th2 polarization. Murine models of RSV infection confirmed that LPS exposure, Tlr4 genotype, and Th2 polarization influence disease phenotypes. Together, the results of this study identify environmental and genetic factors that influence RSV pathogenesis and reveal that a high IL-4/IFN-γ ratio is associated with severe disease. Moreover, these molecules should be explored as potential targets for therapeutic intervention.

Breastfeeding is associated with the production of type I interferon in infants infected with influenza virus.

BACKGROUND: Breast milk-mediated protection against respiratory viruses is well established. However, protective mechanisms are unclear. Type I interferons (IFN) mediate host defence against respiratory viruses, particularly influenza virus. The relationship among type I IFN, respiratory viral infections and breastfeeding has not been explored. METHODS: Type I IFN responses were studied by ELISA and real time PCR in nasal secretions of infants experiencing their first respiratory infection. Modulation of IFN by breastfeeding and other variables affecting severity during viral infection was explored. RESULTS: One hundred and twenty infants were positive by RT-PCR for influenza virus (n = 24), human metapneumovirus (hMPV) (n = 30) or respiratory syncytial virus (RSV) (n = 66). Type I IFNs were detected more frequently in infants infected with influenza virus than in those infected with RSV or hMPV. Breastfeeding promoted higher rates and levels of type I IFN only in infants infected with influenza virus. No effect on IFN production was observed for age, gender or smoking. CONCLUSION: Our study confirms that type I IFN production is detected more frequently in infants infected with influenza virus. Importantly, higher rates and levels of type I IFN in these infants are associated with breastfeeding. These observations suggest that breast milk can protect against respiratory viruses by activating innate antiviral mechanisms in the host.

[Nasal septal abscess]. / Absceso del septum nasal.

A nasal septal abscess (NA) is defined as a collection of pus between the cartilage or bony septum and its normally applied mucoperichondrium or mucoperiostium. It is an uncommon disease which should be suspected in a patient with acute onset of nasal obstruction and recent history of nasal trauma, periodontal infection or an inflammatory process of the rhinosinusal region. We report a case of an 8-year-old boy with bilateral NA caused by community-acquired methicillin-resistant Staphylococcus aureus(MR-CO) in order to emphasize the importance of prompt diagnosis and adequate treatment to prevent the potentially dangerous spread of infection and the development of severe functional and cosmetic sequelae.

Absceso del septum nasal / Nasal septal abscess

Se define como absceso del septum nasal (AN) a la colección de pus entre el cartílago o hueso del septum nasal y el mucopericondrioo mucoperiostio. Se trata de una patología poco frecuente que el pediatra debesospechar ante todo paciente que presente obstrucción nasal deinstalación aguda e historia reciente de traumatismo, infecciónperiodontal o proceso inflamatorio que involucre la regiónrinosinusal. Presentamos el caso de un paciente de 8 años con AN bilateral por Staphylococcus aureus meticilino-resistente de la comunidad (MR-CO), con el objeto de enfatizar la necesidad de un rápido diagnóstico y tratamiento para disminuir el riesgo de complicaciones infecciosas graves y posibles secuelas funcionalesy estéticas.