Clinical and epidemiological study of acute lower respiratory tract infections caused by adenovirus in hospitalized children. Nineteen years of active epidemiological surveillance. / Estudio clínico-epidemiológico de las infecciones respiratorias agudas bajas causadas por adenovirus en niños hospitalizados. Diecinueve años de vigilancia epidemiológica activa.

INTRODUCTION: Acute lower respiratory tract infection (ALRTI) caused by adenovirus is a major cause of morbidity and mortality in children. OBJECTIVES: To describe the clinical and epidemiological pattern and associated factors in hospitalized children. METHODS: Cross-sectional study in children admitted due to ALRTI to Hospital de Niños "Ricardo Gutiérrez," in the Autonomous City of Buenos Aires, between 2000 and 2018. Viral diagnosis was done by indirect immunofluorescence in nasopharyngeal secretions. The clinical and epidemiological characteristics of adenovirus infection were compared to other respiratory viruses (respiratory syncytial virus, influenza, and parainfluenza). A multiple logistic regression was done to identify independent predictors of infection. RESULTS: Out of 16 018 patients with ALRTI, 13 545 were tested for respiratory viruses; 6047 (45 %) had a positive result. Adenovirus was the least common agent (4.4 % [265] of cases); it tended towards a reduction over the study period (peak in 2003) and circulated throughout the year (peak in July). In total, 63.8 % of patients were males; median age: 11 months (interquartile range: 6-20). The most common clinical presentation was pneumonia (63 %). Prior admissions due to respiratory conditions were seen in 50 %; 15.6 % were readmissions; 58.3 % had comorbidities. Ventilatory support was required by 19.2 % and complications were recorded in 44 %. The fatality rate was 7.7 %. Adenovirus infection was associated with age ≥ 12 months, male sex, clinical presentation of pneumonia, prior admissions due to respiratory conditions, and readmissions. CONCLUSIONS: Adenoviruses were less common than other respiratory viruses, although their morbidity and mortality were important.

Introducción. La infección respiratoria aguda baja por adenovirus es una importante causa de morbimortalidad en niños. Objetivos: Describir el patrón clínicoepidemiológico y los factores asociados en niños hospitalizados. Métodos. Estudio transversal en niños ingresados por infección respiratoria aguda baja al Hospital de Niños Ricardo Gutiérrez, Buenos Aires, en 2000-2018. El diagnóstico viral se realizó mediante inmunofluorescencia indirecta en secreciones nasofaríngeas. Se compararon características clínico-epidemiológicas de infección por adenovirus con otros virus respiratorios (virus sincicial respiratorio, influenza y parainfluenza). Se utilizó regresión logística múltiple para identificar predictores independientes de infección. Resultados. De 16018 pacientes con infección respiratoria aguda baja, 13545 fueron testeados para virus respiratorios y 6047 (el 45 %) fueron positivos. Adenovirus fue el agente menos frecuente [el 4,4 % (265) de los casos]; presentó una tendencia en descenso durante todo el período estudiado (pico en 2003) y circuló durante todo el año (pico en julio). El 63,8 % eran varones; mediana de edad: 11 meses (rango intercuartílico: 6-20). La presentación clínica más frecuente fue neumonía (el 63 %). El 50 % tenía internaciones previas por causa respiratoria; el 15,6 % eran reingresos; el 58,3 % tenía comorbilidades. El 19,2 % requirió asistencia ventilatoria; el 44 % registró complicaciones. La letalidad fue del 7,7 %. La infección por adenovirus se asoció a edad ≥ 12 meses, sexo masculino, presentación clínica de neumonía, internaciones previas por causas respiratorias y reinternaciones. Conclusiones. Los adenovirus fueron detectados con menor frecuencia que los otros virus respiratorios, aunque presentaron un importante perfil de morbimortalidad.

Respiratory syncytial virus in preterm infants: 19 years of active epidemiological surveillance in a children's hospital. / Virus sincicial respiratorio en niños nacidos prematuros: 19 años de vigilancia epidemiológica activa en un hospital pediátrico.

INTRODUCTION: Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection (ALRTI) in pediatrics. Preterm infants are at a higher risk for complications. We aimed to describe and compare the clinical and epidemiological characteristics associated with ALRTI due to RSV in preterm and term infants and to establish the predictors of fatality among preterm infants. METHODS: Prospective, cross-sectional study of patients admitted due to ALRTI in the 2000-2018 period. Viral diagnosis was done by indirect immunofluorescence or reverse transcription polymerase chain reaction in nasopharyngeal aspirates. Clinical and epidemiological characteristics were recorded. A multiple logistic regression model established the predictors of fatality among preterm infants. RESULTS: A total of 16 018 ALRTI cases were included; 13 545 (84.6 %) were tested; 6047 (45 %) were positive; RSV was prevalent in 81.1 % (4907), with a seasonal epidemic pattern; 14 % (686) were preterm infants. Comorbidities, perinatal respiratory history, congenital heart disease, malnutrition, chronic respiratory disease, bronchopulmonary dysplasia, prior hospitalization due to ALRTI, and chronic neurological disease (p < 0.001) were more common among preterm infants; they required more intensive care and a longer length of stay, and had a higher fatality rate (p < 0.01). Congenital heart disease was an independent predictor of fatality due to RSV among preterm infants (OR: 3.67 [1.25-10.8], p = 0.01). CONCLUSION: RSV showed an epidemic pattern and affected more preterm infants with certain comorbidities, with a higher morbidity and mortality, compared to term infants. RSV fatality among preterm infants was associated with congenital heart disease.

Introducción. El virus sincicial respiratorio (VSR) es el principal agente causal de la infección respiratoria aguda baja (IRAB) en pediatría. Los niños prematuros tienen mayor riesgo de complicaciones asociadas con esta infección. Los objetivos fueron describir y comparar las características clínicas y epidemiológicas asociadas a IRAB por VSR en niños/as nacidos pretérmino y a término, y establecer predictores de letalidad en los prematuros. Métodos. Estudio prospectivo, transversal, de pacientes ingresados por IRAB, en el período 2000-2018. El diagnóstico virológico se realizó mediante inmunofluorescencia indirecta o reacción en cadena de la polimerasa con transcriptasa inversa de aspirados nasofaríngeos. Se registraron las características clínicoepidemiológicas. Se desarrolló un modelo de regresión logística múltiple para establecer los predictores de letalidad en prematuros. Resultados. Se incluyeron 16 018 casos de IRAB; 13 545 (el 84,6 %) fueron estudiados; 6047 (el 45 %) positivos; VSR predominó en el 81,1 % (4907); mostró un patrón epidémico estacional; el 14 % (686) fueron prematuros. Los prematuros mostraron mayor frecuencia de comorbilidades, antecedentes respiratorios perinatales, cardiopatía congénita, desnutrición, enfermedad respiratoria crónica, displasia broncopulmonar, hospitalización previa por IRAB y enfermedad neurológica crónica (p < 0,001); requirieron más cuidados intensivos, mayor tiempo de internación y mayor tasa de letalidad (p < 0,01). La cardiopatía congénita fue predictor independiente de letalidad por VSR en prematuros [OR 3,67 (1,25-10,8), p = 0,01]. Conclusión. VSR mostró un patrón epidémico, afectó a prematuros con ciertas comorbilidades con mayor morbimortalidad que los de término. La letalidad por VSR en prematuros se asoció con la cardiopatía congénita.

Burden of Respiratory Syncytial Virus Disease and Mortality Risk Factors in Argentina: 18 Years of Active Surveillance in a Children's Hospital.

BACKGROUND: Respiratory syncytial virus is the leading cause of acute lower respiratory infection in children. We aimed to describe the clinical-epidemiologic pattern and risk factors for mortality associated with RSV infection. METHODS: This is a prospective, cross-sectional study of acute lower respiratory infection in children admitted to the Children's Hospital during 2000 to 2017. Viral diagnosis was made by fluorescent antibody techniques or real-time-polymerase chain reaction. We compared clinical-epidemiologic characteristics of RSV infection in nonfatal versus fatal cases. Multiple logistic regression was used to identify independent predictors of mortality. RESULTS: Of 15,451 patients with acute lower respiratory infection, 13,033 were tested for respiratory viruses and 5831 (45%) were positive: RSV 81.3% (4738), influenza 7.6% (440), parainfluenza 6.9% (402) and adenovirus 4.3% (251). RSV had a seasonal epidemic pattern coinciding with months of lowest average temperature. RSV cases show a case fatality rate of 1.7% (82/4687). Fatal cases had a higher proportion of prematurity (P < 0.01), perinatal respiratory history (P < 0.01), malnourishment (P < 0.01), congenital heart disease (P < 0.01), chronic neurologic disease (P < 0.01) and pneumonia at clinical presentation (P = 0.014). No significant difference between genders was observed. Most deaths occurred among children who had complications: respiratory distress (80.5%), nosocomial infections (45.7%), sepsis (31.7%) and atelectasis (13.4%). Independent predictors of RSV mortality were moderate-to-severe malnourishment, odds ratio (OR): 3.69 [95% confidence interval (CI): 1.98-6.87; P < 0.0001]; chronic neurologic disease, OR: 4.14 (95% CI: 2.12-8.08; P < 0.0001); congenital heart disease, OR: 4.18 (95% CI: 2.39-7.32; P< 0.0001); and the age less than 6 months, OR: 1.99 (95% CI: 1.24-3.18; P = 0.004). CONCLUSIONS: RSV showed an epidemic pattern affecting mostly young children. Malnourishment, chronic neurologic disease, congenital heart disease and the age less than 6 months were the independent risk factors for RSV mortality.

Influenza virus: 16 years' experience of clinical epidemiologic patterns and associated infection factors in hospitalized children in Argentina.

BACKGROUND: Influenza is an important cause of acute lower respiratory tract infection (aLRTI), hospitalization, and mortality in children. This study aimed to describe the clinical and epidemiologic patterns and infection factors associated with influenza, and compare case features of influenza A and B. METHODS: In a prospective, cross-sectional study, patients admitted for aLRTI, between 2000 and 2015, were tested for respiratory syncytial virus, adenovirus, influenza, or parainfluenza, and confirmed by fluorescent antibody (FA) or real-time polymerase chain reaction (RT-PCR) assay of nasopharyngeal aspirates. RESULTS: Of 14,044 patients, 37.7% (5290) had FA- or RT-PCR-confirmed samples that identified influenza in 2.8% (394/14,044; 91.4% [360] influenza A, 8.6% [34] influenza B) of cases. Influenza frequency followed a seasonal epidemic pattern (May-July, the lowest average temperature months). The median age of cases was 12 months (interquartile range: 6-21 months); 56.1% (221/394) of cases were male. Consolidated pneumonia was the most frequent clinical presentation (56.9%; 224/394). Roughly half (49.7%; 196/394) of all cases had previous respiratory admissions; 9.4% (37/394) were re-admissions; 61.5% (241/392) had comorbidities; 26.2% (102/389) had complications; 7.8% (30/384) had nosocomial infections. The average case fatality rate was 2.1% (8/389). Chronic neurologic disease was significantly higher in influenza B cases compared to influenza A cases (p = 0.030). The independent predictors for influenza were: age ≥6 months, odds ratio (OR): 1.88 (95% confidence interval [CI]: 1.44-2.45); p<0.001; presence of chronic neurologic disease, OR: 1.48 (95% CI: 1.01-2.17); p = 0.041; previous respiratory admissions, OR: 1.71 (95% CI: 1.36-2.14); p<0.001; re-admissions, OR: 1.71 (95% CI: 1.17-2.51); p = 0.006; clinical pneumonia, OR: 1.50 (95% CI: 1.21-1.87); p<0.001; immunodeficiency, OR: 1.87 (95% CI: 1.15-3.05); p = 0.011; cystic fibrosis, OR: 4.42 (95% CI: 1.29-15.14); p = 0.018. CONCLUSION: Influenza showed an epidemic seasonal pattern (May-July), with higher risk in children ≥6 months, or with pneumonia, previous respiratory admissions, or certain comorbidities.

PCV13 vaccination impact: A multicenter study of pneumonia in 10 pediatric hospitals in Argentina.

INTRODUCTION: In 2012, PCV13 was introduced into the National Immunization Program in Argentina, 2+1 schedule for children <2 years. Coverage rates for 1st and 3rd doses were 69% and 41.0% in 2012, 98% and 86% in 2013; 99% and 89% in 2014, respectively. The aims of this study were to evaluate impact of PCV13 on Consolidated Pneumonia (CP) and Pneumococcal Pneumonia (PP) burden, and to describe epidemiological-clinical pattern of PP during the three-year period following vaccine introduction. METHODS: Hospital-based study at 10 pediatric surveillance units in Argentina. CP and PP discharge rates per 10,000 hospital discharges were compared between the pre-vaccination period 2007-2011 (preVp), the year of intervention (2012) and the post-vaccination period 2013-2014 (postVp). RESULTS: Significant reduction in CP and PP discharge rates was observed in patients <5 years [% reduction (95%CI)]: 10.2% (6.3; 14.0) in 2012 and 24.8% (21.3; 28.2) in postVp for CP discharge rate; 59.5% (48.0; 68.5) in 2012 and 68.8% (58.3; 76.6) in postVp for PP discharge rate. Significant changes were also observed in children ≥5 years, mainly in PP discharge rate. A total of 297 PP cases were studied; 59.3% male; 31.3% <2 years; 42.9% had received PCV13 in 2012 and 84.5% in posVp. Case fatality rate was 3.4%. PCV13 serotypes decreased from 83.0% (39/47) in 2012 to 64.2% (52/81) in postVp, p = 0.039. CONCLUSIONS: After PCV13 introduction, significant reduction in CP and PP discharge rates was observed in hospitalized children <5 years. In patients ≥5 years, PP discharge rate also decreased significantly.

Community-acquired methicillin-resistant Staphylococcus aureus infections: hospitalization and case fatality risk in 10 pediatric facilities in Argentina. / Infecciones por Staphylococcus aureus meticilino resistente adquirido en la comunidad: hospitalización y riesgo de letalidad en 10 centros pediátricos de Argentina.

INTRODUCTION: Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are prevalent both in Argentina and worldwide, and they may have a severe clinical course. OBJECTIVES: To estimate the hospitalization rate and case fatality risk factors of CA-MRSA infection. METHODS: Cross-sectional, analytical study. All patients < 15 years old with community-acquired Staphylococcus aureus (CA-SA) infections admitted to 10 pediatric facilities between January 2012 and December 2014 were included. RESULTS: Out of 1141 patients with CA-SA, 904 (79.2%) had CA-MRSA. The rate of hospitalization of CA-MRSA cases (per 10 000 discharges) among patients < 5 years old was 27.6 in 2012, 35.2 in 2013, and 42.7 in 2014 (p = 0.0002). The 2-4-year-old group was the most affected one: 32.2, 49.4, and 54.4, respectively (p = 0.0057). The clinical presentations included skin and soft tissue infections: 66.2%, pneumonia: 11.5%, sepsis/bacteremia: 8.5%, osteomyelitis: 5.5%, arthritis: 5.2%, psoas abscess: 1.0%, pericarditis/endocarditis: 0.8%, meningitis: 0.6%, and other: 0.7%. In terms of antibiotic resistance, 11.1% had resistance to erythromycin; 8.4%, to gentamicin; and 0.6%, to trimethoprim-sulfamethoxazole. All strains were susceptible to vancomycin. The case fatality rate was 2.2% and associated risk factors were (odds ratio [95% confidence interval]) age > 8 years (2.78, 1.05-7.37), pneumonia (6.37, 2.3717.09), meningitis (19.53, 2.40-127.87), and sepsis/bacteremia (39.65, 11.94-145.55). CONCLUSIONS: The rate of CA-MRSA infection was high; the rate of hospitalization increased in the 2013-2014 period; the 2-4-year-old group was the most affected one. A higher case fatality risk was observed among patients > 8 years old and those with the clinical presentations of pneumonia, meningitis, and sepsis.

INTRODUCCIÓN: Las infecciones por Staphylococcus aureusmeticilino resistente adquirido en la comunidad (SAMR-C) son prevalentes en Argentina y el mundo; pueden tener evolución grave. OBJETIVOS: Estimar tasa de hospitalización y factores de riesgo de letalidad de la infección por SAMR-C. MÉTODOS: Estudio analítico transversal. Se incluyeron todos los pacientes < 15 años con infección por Staphylococcus aureusadquirido en la comunidad (SA-C) hospitalizados en 10 centros pediátricos, entre enero/2012-diciembre/2014. RESULTADOS: Del total de 1141 pacientes con infección por SA-C, 904 (79,2%) fueron SAMR-C. La tasa de hospitalización de casos de SAMR-C (por 10 000 egresos) en < 5 años fue 27,6 en 2012, 35,2 en 2013 y 42,7 en 2014 (p= 0,0002). El grupo de 2-4 años fue el más afectado: 32,2, 49,4 y 54,4, respectivamente (p= 0,0057). Las presentaciones clínicas fueron infección de piel y partes blandas (IPPB): 66,2%; neumonía:11,5%; sepsis/bacteriemia: 8,5%; osteomielitis: 5,5%; artritis: 5,2%; absceso de psoas: 1,0%; pericarditis/endocarditis: 0,8%; meningitis: 0,6%; otras: 0,7%. La resistencia antibiótica fue, para eritromicina, 11,1%; clindamicina, 11,0%; gentamicina, 8,4%; trimetoprima-sulfametoxazol: 0,6%. Todas las cepas fueron sensibles a vancomicina. La letalidad fue 2,2% y los factores de riesgo asociados fueron [OR (IC 95%)] edad > 8 años (2,78; 1,05-7,37), neumonía (6,37; 2,37-17,09), meningitis (19,53; 2,40-127,87) y sepsis/bacteriemia (39,65; 11,94-145,55). CONCLUSIONES: La tasa de infección por SAMR-C fue alta; la tasa de hospitalización aumentó en 2013-14; el grupo de 2-4 años fue el más afectado. Presentaron mayor riesgo de letalidad los > 8 años y las clínicas de neumonía, meningitis y sepsis.

Meningococcal Disease in Children in Argentina A 3-year Active Sentinel Hospital Surveillance Study.

BACKGROUND: Meningococcal disease (MD) is a medical emergency and a serious public health problem. As new meningococcal vaccines become available, MD surveillance is crucial to provide baseline epidemiologic data before implementing preventive measures. We estimated MD incidence and epidemiology in Argentina using hospital-based surveillance. METHODS: Three-year prospective active surveillance in patients ≤15 years of age was conducted at 6 pediatric hospital sentinel units (March 2012 to February 2015). RESULTS: Of 184,360 hospitalized patients, 1444 (0.78%) had suspected meningitis or MD. Of these, 268 (19%) presented probable acute bacterial meningitis or MD, 168 (63%) were culture positive and 51 (30%) tested positive for Neisseria meningitidis. Of 100 culture-negative cases, 30 had positive meningococcal polymerase chain reaction. Thirteen patients presented other uncommon MD manifestations, resulting in a total of 94 MD cases and an annual incidence of 5.1/10 hospitalized patients [95% confidence interval (CI): 4-6]. Fifty-four (57%) patients were males, 48% were <1 year of age and the median age was 12.5 months (1 month to 15 years). Clinical presentations were the following: meningococcemia and meningitis (37%), meningitis (30%), meningococcemia (16%), arthritis (10%), bacteremia (5%) and pneumonia (2%). Twenty-eight percent had complications. Nine children died (case fatality rate: 10%), and 8 had sequelae. Serogroups were identified for 84 isolates. Serogroup W was associated with age <1 year (odds ratio: 3.18; 95% CI: 1.14-8.99); meningococcemia was associated with mortality (P = 0.0038). CONCLUSIONS: Highest rates of MD were observed among young infants. This study provides baseline data to estimate the impact of introducing meningococcal vaccines in Argentina.

[Impact of the 13-valent pneumococcal conjugate vaccine on the incidence of consolidated pneumonia in children younger than 5 years old in Pilar, Buenos Aires: A population-based study]. / Impacto de la vacuna neumocócica conjugada 13-valente en la incidencia de neumonía consolidante en menores de 5 anos en el partido de Pilar, Buenos Aires: estudio de base poblacional.

INTRODUCTION: In January 2012, Argentina introduced the 13-valent pneumococcal conjugate vaccine (PCV13) in its immunization schedule for children younger than 2 years old. Coverage in Pilar in 2012 reached>90% for the first two doses and 60% for the third dose. OBJECTIVE: To measure the effectiveness of PCV13 to reduce the incidence of consolidated pneumonia (CP)in the two-year period following its introduction in the immunization schedule. METHODS: Prospective, population-based study conducted in Pilar. All children younger than 5 year sold with clinical signs of pneumonia assisted at the reference hospitals (both inpatients and outpatients) in the first two years since the vaccine introduction (2012-2013) were included. The annual incidence of CP was compared to the 2003-2005 baseline period. Clinical and radiological assessments were done as per the World Health Organization's criteria. RESULTS: Six hundred and sixty-six patients with clinical suspicion of pneumonia were included. CP was diagnosed in 309 patients; 52.1% were girls, 70.2% were younger than 2 years old, and 56.4% had been immunized with the PCV13; 4.5% (14/309) had bacteriological confirmation (S. pneumoniae: 4; N. meningitidis: 4; S. aureus: 2; others: 4). A significant reduction in the incidence of CP (per 100 000 children younger than 5 years old) was observed between the pre- and postimmunization periods, from 750 (204/27209) to 561 (171/30 475) in 2012 and to 453 (138/30 475) in 2013; effectiveness accounted for 25.2% and 39.6%, respectively. Reduction in infants younger than 1 year old: 33.9% in 2012 and 44.6% in 2013; and in children aged 12-23 months old: 57.9% in 2013. No significant differences were observed in the incidence of CP at an older age. CONCLUSIONS: Following the introduction of PCV13 in Argentina's immunization schedule, a fast and significant reduction in the incidence of CP was observed, mainly in infants younger than 1 year old in 2012 and in children younger than 2 years old in 2013.

Introducción. En enero de 2012, en Argentina, fue introducida la vacuna neumocócica conjugada 13-valente (13-Valent Pneumococcal Conjugate Vaccine; PCV13, por sus siglas en inglés) en el Calendario Nacional, en menores de 2 años. La cobertura en el partido de Pilar en 2012 fue > 90% para las primeras 2 dosis y 60% para la tercera. Objetivo. Medir la efectividad de la PCV13 en la reducción de la incidencia de neumonías consolidantes (NC), durante los dos años siguientes a su introducción en el Calendario. Métodos. Estudio prospectivo de base poblacional en Pilar. Se incluyeron todos los menores de 5 años con signos clínicos de neumonía atendidos en hospitales de referencia (ambulatorios y hospitalizados) en los primeros 2 años de la incorporación (2012-2013). Se comparó la incidencia anual de NC con el período basal 2003-2005. Evaluación clínica-radiológica, según criterio de la Organización Mundial de la Salud. Resultados. Se incluyeron 666 pacientes con sospecha clínica de neumonía. Se diagnosticó NC en 309 pacientes; 52,1% de mujeres, 70,2% menores de 2 años y 56,4% vacunado con PCV13; 4,5% (14/309) con bacteriología confirmada (S. pneumoniae: 4; N. meningitidis: 4; S. aureus: 2; otros: 4). Se observó una reducción significativa en la incidencia de NC (por 100 000 niños menores de 5 años) entre los períodos pre y posvacunal de 750 (204/27 209) a 561 (171/30 475) en 2012 y 453 (138/30 475) en 2013; efectividad de 25,2% y 39,6%, respectivamente. Reducción en menores de 1 año: 33,9% en 2012 y 44,6% en 2013; y en niños de 12-23 meses: 57,9% en 2013. No se observaron diferencias significativas en las incidencias en edades mayores. Conclusiones. Luego de la introducción de la PCV13 en el Calendario de Vacunación en Argentina, se observó una reducción rápida y significativa en la incidencia de NC, principalmente en menores de 1 año en 2012 y menores de 2 años en 2013.

Virus sincicial respiratorio en niños nacidos prematuros: 19 años de vigilancia epidemiológica activa en un hospital pediátrico / Respiratory syncytial virus in preterm infants: 19 years of active epidemiological surveillance in a children's hospital

Introducción. El virus sincicial respiratorio (VSR) es el principal agente causal de la infección respiratoria aguda baja (IRAB) en pediatría. Los niños prematuros tienen mayor riesgo de complicaciones asociadas con esta infección. Los objetivos fueron describir y comparar las características clínicas y epidemiológicas asociadas a IRAB por VSR en niños/as nacidos pretérmino y a término, y establecer predictores de letalidad en los prematuros.Métodos. Estudio prospectivo, transversal, de pacientes ingresados por IRAB, en el período 2000-2018. El diagnóstico virológico se realizó mediante inmunofluorescencia indirecta o reacción en cadena de la polimerasa con transcriptasa inversa de aspirados nasofaríngeos. Se registraron las características clínico-epidemiológicas. Se desarrolló un modelo de regresión logística múltiple para establecer los predictores de letalidad en prematuros.Resultados. Se incluyeron 16 018 casos de IRAB; 13 545 (el 84,6 %) fueron estudiados; 6047 (el 45 %) positivos; VSR predominó en el 81,1 % (4907); mostró un patrón epidémico estacional; el 14 % (686) fueron prematuros.Los prematuros mostraron mayor frecuencia de comorbilidades, antecedentes respiratorios perinatales, cardiopatía congénita, desnutrición, enfermedad respiratoria crónica, displasia broncopulmonar, hospitalización previa por IRAB y enfermedad neurológica crónica (p < 0,001); requirieron más cuidados intensivos, mayor tiempo de internación y mayor tasa de letalidad (p < 0,01). La cardiopatía congénita fue predictor independiente de letalidad por VSR en prematuros [OR 3,67 (1,25-10,8), p = 0,01].Conclusión. VSR mostró un patrón epidémico, afectó a prematuros con ciertas comorbilidades con mayor morbimortalidad que los de término. La letalidad por VSR en prematuros se asoció con la cardiopatía congénita.

Introduction. Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection (ALRTI) in pediatrics. Preterm infants are at a higher risk for complications. We aimed to describe and compare the clinical and epidemiological characteristics associated with ALRTI due to RSV in preterm and term infants and to establish the predictors of fatality among preterm infants.Methods. Prospective, cross-sectional study of patients admitted due to ALRTI in the 2000-2018 period. Viral diagnosis was done by indirect immunofluorescence or reverse transcription polymerase chain reaction in nasopharyngeal aspirates. Clinical and epidemiological characteristics were recorded. A multiple logistic regression model established the predictors of fatality among preterm infants.Results. A total of 16 018 ALRTI cases were included; 13 545 (84.6 %) were tested; 6047 (45 %) were positive; RSV was prevalent in 81.1 % (4907), with a seasonal epidemic pattern; 14 % (686) were preterm infants.Comorbidities, perinatal respiratory history, congenital heart disease, malnutrition, chronic respiratory disease, bronchopulmonary dysplasia, prior hospitalization due to ALRTI, and chronic neurological disease (p < 0.001) were more common among preterm infants; they required more intensive care and a longer length of stay, and had a higher fatality rate (p < 0.01). Congenital heart disease was an independent predictor of fatality due to RSV among preterm infants (OR: 3.67 [1.25-10.8], p = 0.01).Conclusion. RSV showed an epidemic pattern and affected more preterm infants with certain comorbidities, with a higher morbidity and mortality, compared to term infants. RSV fatality among preterm infants was associated with congenital heart disease.

Estudio clínico-epidemiológico de las infecciones respiratorias agudas bajas causadas por adenovirus en niños hospitalizados. Diecinueve años de vigilancia epidemiológica activa / Clinical and epidemiological study of acute lower respiratory tract infections caused by adenovirus in hospitalized children. Nineteen years of active epidemiological surveillance

Introducción. La infección respiratoria aguda baja por adenovirus es una importante causa de morbimortalidad en niños. Objetivos: Describir el patrón clínico-epidemiológico y los factores asociados en niños hospitalizados.Métodos. Estudio transversal en niños ingresados por infección respiratoria aguda baja al Hospital de Niños Ricardo Gutiérrez, Buenos Aires, en 2000-2018. El diagnóstico viral se realizó mediante inmunofluorescencia indirecta en secreciones nasofaríngeas. Se compararon características clínico-epidemiológicas de infección por adenovirus con otros virus respiratorios (virus sincicial respiratorio, influenza y parainfluenza). Se utilizó regresión logística múltiple para identificar predictores independientes de infección.Resultados. De 16018 pacientes con infección respiratoria aguda baja, 13545 fueron testeados para virus respiratorios y 6047 (el 45 %) fueron positivos. Adenovirus fue el agente menos frecuente [el 4,4 % (265) de los casos]; presentó una tendencia en descenso durante todo el período estudiado (pico en 2003) y circuló durante todo el año (pico en julio). El 63,8 % eran varones; mediana de edad: 11 meses (rango intercuartílico: 6-20). La presentación clínica más frecuente fue neumonía (el 63 %). El 50 % tenía internaciones previas por causa respiratoria; el 15,6 % eran reingresos; el 58,3 % tenía comorbilidades. El 19,2 % requirió asistencia ventilatoria; el 44 %registró complicaciones. La letalidad fue del 7,7 %. La infección por adenovirus se asoció a edad ≥ 12 meses, sexo masculino, presentación clínica de neumonía, internaciones previas por causas respiratorias y reinternaciones.Conclusiones. Los adenovirus fueron detectados con menor frecuencia que los otros virus respiratorios, aunque presentaron un importante perfil de morbimortalidad

Introduction. Acute lower respiratory tract infection (ALRTI) caused by adenovirus is a major cause of morbidity and mortality in children.Objectives. To describe the clinical and epidemiological pattern and associated factors in hospitalized children.Methods. Cross-sectional study in children admitted due to ALRTI to Hospital de Niños "Ricardo Gutiérrez," in the Autonomous City of Buenos Aires, between 2000 and 2018. Viral diagnosis was done by indirect immunofluorescence in nasopharyngeal secretions. The clinical and epidemiological characteristics of adenovirus infection were compared to other respiratory viruses (respiratory syncytial virus, influenza, and parainfluenza). A multiple logistic regression was done to identify independent predictors of infection.Results. Out of 16 018 patients with ALRTI, 13 545 were tested for respiratory viruses; 6047 (45 %) had a positive result. Adenovirus was the least common agent (4.4 % [265] of cases); it tended towards a reduction over the study period (peak in 2003) and circulated throughout the year (peak in July). In total, 63.8 % of patients were males; median age: 11 months (interquartile range: 6-20). The most common clinical presentation was pneumonia (63 %). Prior admissions due to respiratory conditions were seen in 50 %; 15.6 %were readmissions; 58.3 % had comorbidities. Ventilatory support was required by 19.2 %and complications were recorded in 44 %. The fatality rate was 7.7 %. Adenovirus infection was associated with age ≥ 12 months, male sex, clinical presentation of pneumonia, prior admissions due to respiratory conditions, and readmissions.Conclusions. Adenoviruses were less common than other respiratory viruses, although their morbidity and mortality were important

Respiratory syncytial virus: clinical and epidemiological pattern in pediatric patients admitted to a children's hospital between 2000 and 2013.

INTRODUCTION: Respiratory syncytial virus (RSV) is the major causative organism associated with acute lower respiratory tract infections in children.The objective of this study was to describe the clinical and epidemiological pattern of RSV and identify risk factors for RSV infection. POPULATION AND METHODS: Prospective, cohort study on patients hospitalized due to acute lower respiratory tract infection at Hospital de Niños Ricardo Gutiérrez between March and November throughout the 2000-2013 period. The virological diagnosis of RSV, adenovirus, influenza and parainfluenza was performed by indirect immunofluorescence using nasopharyngeal aspirates. RESULTS: A total of 12,555 children were included, 38.2% (4798) had virus rescued from samples. RSV accounted for 81.8% of cases (3924/4798) with no significant annual variations (71.2- 88.1) and with an epidemic seasonal pattern(May through July); RSV was followed by influenza (7.6%), parainfluenza (5.9%), and adenovirus (4.7%).The median age of patients with RSV rescue (3924) was 7 months old (0- 214 months old), while 74.2% were younger than 1 year old, 43.1% were younger than 6 months old, 56.5% were males and the most common clinical presentation was bronchiolitis (60.7%). Comorbidities were observed in 41.6% of cases. The most common comorbidities were chronic respiratory disease (74%), congenital heart disease (14%), and chronic neurological disease (10.2%).Complications occurred in 25%of cases. The case fatality rate was 1.9% (74/3888). Independent predictors of RSV infection were age <3 months old (OR: 2.8 [2.14-3.67], p < 0.01),clinical presentation of bronchiolitis (OR: 1.54 [1.32-1.79], p < 0.01), and hypoxemia at the time of admission (OR: 1.84 [1.42-2.37], p < 0.01). CONCLUSIONS: RSV infection displayed a seasonal pattern and was associated with infants younger than 3 months old with bronchiolitis and hypoxemia at the time of admission.

Eficacia, efectividad e impacto en vacunas: ¿es lo mismo? / Vaccine efficacy, effectiveness and impact: is it the same?

Antes de la aprobación por las autoridades regulatorias, una vacuna debe demostrar su seguridad y eficacia mediante ensayos clínicos. De todos modos, una vez licenciada, se necesita un seguimiento continuo para evaluar la seguridad y efectividad de la vacuna, así como su impacto en los programas de vacunación. Los términos efectividad vacunal e impacto de un programa de vacunación son ampliamente usados en la literatura para evaluar la protección post-licencia, sin embargo sus significados y diseños de investigación apropiados por lo general no están claramente estandarizados. El objetivo de este artículo es clarificar estos conceptos (eficacia, efectividad e impacto), y describir los diseños de investigación más utilizados para evaluarlos

Before their approval by regulatory authorities, vaccines must demonstrate their safety and efficacy through clinical trials. In any case, once vaccines are licensed, continuous monitoring is needed to evaluate their safety and effectiveness, as well as the impact of vaccination programs. The terms 'vaccine effectiveness' and 'impact' of a vaccination program are widely used in the literature to assess post-license protection; however, their meanings and appropriate research designs are not usually clearly standardized. The aim of this article is to clarify these concepts (efficacy, effectiveness and impact), and to describe the most commonly used research designs to evaluate them

Actualización sobre enfermedad meningocócica y su prevención / Update on meningococcal disease and its prevention

En Argentina la enfermedad meningocócica (EM) tiene un comportamiento endemo-epidémico y los niños <5 años son los más afectados, la letalidad es del 10%, con mayor impacto en <1 año. Históricamente los serogrupos predominantes fueron B y C y en la actualidad prevalecen los serogrupos W y B. En 2017 Argentina incorporó la vacunación meningocócica (Resolución 10/2015) con un esquema de 2+1 (3 meses-5 meses-15/18 meses) de la vacuna conjugada cuadrivalente ACWY-CRM197-Menveo®. La estrategia incluye una única dosis de vacuna a los 11 años, con el objetivo de disminuir la portación orofaríngea y así contribuir a la disminución de la incidencia de EM en el grupo más vulnerable. El programa también provee la vacunación para huéspedes especiales. También se encuentran disponibles la vacuna cuadrivalente ACWY conjugada con toxoide diftérico (MenACYW-D)-Menactra®, licenciada para niños ≥9 meses hasta los 55 años, y la vacuna meningocócica B multicomponente recombinante (MenB-4C)-Bexsero®. Esta última aprobada en 2015 para su uso en ≥2 meses de vida. Estudios post licencia demostraron un alto nivel de protección y de seguridad de la vacuna. Es por el momento una vacuna de indicación individual que se está analizando en la esfera de Salud Pública

Meningococcal disease (MD) is endemoepidemic in Argentina, where most cases occur in children <5 years of age, and the fatality rate is 10% with the highest impact among infants <1 year of age. Historically, the predominant serogroups were B and C, and the serogroups W and B prevail at present. In 2017, the meningococcal vaccine was introduced in the Argentine National Immunization Program with a two-dose plus a booster schedule (3 months-5 months-15/18 months) of the quadrivalent meningococcal conjugate vaccine MenACWY-CRM197 (Menveo®). The strategy includes a single dose of the vaccine at 11 years of age, with the aim of reducing oropharyngeal carriage, thus contributing to the reduction of the MD incidence in the most vulnerable group. The program also provides vaccination for special hosts. There are also other vaccines available privately, such as the quadrivalent meningococcal conjugate vaccine MenACWY-D (Menactra®), licensed for children ≥9 months of age up to 55 years of age, and the multicomponent meningococcal serogroup B vaccine 4CMenB (Bexsero®). This vaccine was approved in 2015 for use in ≥2 months of age. Post-license studies demonstrated its strong protection and safety. It is, for the time being, a vaccine of individual indication that is being analyzed in the Public Health area

Infecciones por Staphylococcus aureus meticilino resistente adquirido en la comunidad: hospitalización y riesgo de letalidad en 10 centros pediátricos de Argentina / Community-acquired methicillin-resistant Staphylococcus aureus infections: hospitalization and case fatality risk in 10 pediatric facilities in Argentina

Introducción. Las infecciones por Staphylococcus aureusmeticilino resistente adquirido en la comunidad (SAMR-C) son prevalentes en Argentina y el mundo; pueden tener evolución grave. Objetivos: Estimar tasa de hospitalización y factores de riesgo de letalidad de la infección por SAMR-C. Métodos. Estudio analítico transversal. Se incluyeron todos los pacientes < 15 años con infección por Staphylococcus aureusadquirido en la comunidad (SA-C) hospitalizados en 10 centros pediátricos, entre enero/2012-diciembre/2014. Resultados. Del total de 1141 pacientes con infección por SA-C, 904 (79,2%) fueron SAMR-C. La tasa de hospitalización de casos de SAMR-C (por 10 000 egresos) en < 5 años fue 27,6 en 2012, 35,2 en 2013 y 42,7 en 2014 (p= 0,0002). El grupo de 2-4 años fue el más afectado: 32,2, 49,4 y 54,4, respectivamente (p= 0,0057). Las presentaciones clínicas fueron infección de piel y partes blandas (IPPB): 66,2%; neumonía:11,5%; sepsis/bacteriemia: 8,5%; osteomielitis: 5,5%; artritis: 5,2%; absceso de psoas: 1,0%; pericarditis/endocarditis: 0,8%; meningitis: 0,6%; otras: 0,7%. La resistencia antibiótica fue, para eritromicina, 11,1%; clindamicina, 11,0%; gentamicina, 8,4%; trimetoprima-sulfametoxazol: 0,6%. Todas las cepas fueron sensibles a vancomicina. La letalidad fue 2,2% y los factores de riesgo asociados fueron --#91;OR (IC 95%)--#93; edad > 8 años (2,78; 1,05-7,37), neumonía (6,37; 2,37-17,09), meningitis (19,53; 2,40-127,87) y sepsis/bacteriemia (39,65; 11,94-145,55). Conclusiones. La tasa de infección por SAMR-C fue alta; la tasa de hospitalización aumentó en 2013-14; el grupo de 2-4 años fue el más afectado. Presentaron mayor riesgo de letalidad los > 8 años y las clínicas de neumonía, meningitis y sepsis.

Introduction. Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are prevalent both in Argentina and worldwide, and they may have a severe clinical course. Objectives: To estimate the hospitalization rate and case fatality risk factors of CA-MRSA infection. Methods. Cross-sectional, analytical study. All patients < 15 years old with community-acquired Staphylococcus aureus (CA-SA) infections admitted to 10 pediatric facilities between January 2012 and December 2014 were included. Results. Out of 1141 patients with CA-SA, 904 (79.2%) had CA-MRSA. The rate of hospitalization of CA-MRSA cases (per 10 000 discharges) among patients < 5 years old was 27.6 in 2012, 35.2 in 2013, and 42.7 in 2014 (p = 0.0002). The 2-4-year-old group was the most affected one: 32.2, 49.4, and 54.4, respectively (p = 0.0057). The clinical presentations included skin and soft tissue infections: 66.2%, pneumonia: 11.5%, sepsis/bacteremia: 8.5%, osteomyelitis: 5.5%, arthritis: 5.2%, psoas abscess: 1.0%, pericarditis/endocarditis: 0.8%, meningitis: 0.6%, and other: 0.7%. In terms of antibiotic resistance, 11.1% had resistance to erythromycin; 8.4%, to gentamicin; and 0.6%, to trimethoprim-sulfamethoxazole. All strains were susceptible to vancomycin. The case fatality rate was 2.2% and associated risk factors were (odds ratio --#91;95% confidence interval--#93;) age > 8 years (2.78, 1.05-7.37), pneumonia (6.37, 2.3717.09), meningitis (19.53, 2.40-127.87), and sepsis/bacteremia (39.65, 11.94-145.55). Conclusions. The rate of CA-MRSA infection was high; the rate of hospitalization increased in the 2013-2014 period; the 2-4-year-old group was the most affected one. A higher case fatality risk was observed among patients > 8 years old and those with the clinical presentations of pneumonia, meningitis, and sepsis.

[Delayed vaccine schedule and missed opportunities for vaccination in children up to 24 months. A multicenter study]. / Esquemas atrasados de vacunación y oportunidades perdidas de vacunación en niños de hasta 24 meses: estudio multicéntrico.

INTRODUCTION: Delayed vaccine schedule (DVS) and missed opportunities of vaccination (MOV) are some of the main causes of low coverage in children ≤24 month in Argentina. OBJECTIVES: To determine the prevalence of DVS and the rate of MOV during the frst 24 months of life and risk factors for their occurrence. POPULATION AND METHODS: We conducted a survey among children ≤24 month's caregivers at five hospitals in different departments, between August-December/2008. RESULTS: Total enrolled: 1591 children; 54.2% male, median of age 8 months (0-24 months). Eighty percent concurred with vaccine-card, 75.9% consulted by pathology. Overall DVS rate: 39.7%. Most common DVS reason: the current mild disease: 38.5%. Overall MOV rate: 19.8%. Most common MOV reason: no detection of the need to vaccinate 47.8%. DTPHib and OPV vaccines had a higher risk of DVS and MOV. DVS independent predictors: age ≥6 months, administration for additionally recommended vaccines and prolonged waiting in the last vaccination. MOV independent predictors were: age ≥6 months, no compliance with prior care, and not asking for vaccines. CONCLUSION: We found a high proportion of MOV and mainly of DVS; they were associated mostly to false contraindications, lack of questioning on vaccines and difficulties in the quality of care provided to parents.

[Study of respiratory influenza A H1N1 Virus (pH1N1) in hospitalized children in the pandemic year. Experience in 34 centers in Argentina]. / Estudio de las enfermedades respiratorias por virus Influenza A H1N1 (pH1N1) en niños internados durante el año de la pandemia. Experiencia de 34 centros en la Argentina.

INTRODUCTION: In Argentina, pandemic influenza pH1N1 caused nearly 10,000 confirmed cases with high impact in pediatrics. OBJECTIVES: To describe clinical and epidemiological characteristics and analyse the risk factor of lethality in children hospitalized with infection pH1N1 confirmed by PCR. POPULATION AND METHODS: We identifed all suspected cases (according to Ministry of health) in 34 centers and we included all the confirmed cases of 0-18 years from 1/4/09 to 31/8/09 in a retrospective cohort study. The viral diagnosis was confirmed by RT-PCR method. Data are expressed in percentages, average, median, standard deviation, and range (IQR) as appropriate; and as a measure of association, relative risk (RR), with 95% confidence interval (95%CI). Multiple logistic regression was conducted to determine the independent risk predictors. RESULTS: Total number of suspected cases were: 2367; PCR was performed to 47.8% (n: 1131) being positive for pH1N1 65.5% (n: 741/1131); 57.2% males; 61.5% <24 months, median age: 14 months (IQR 6-46 months); 45.1% with underlying disease; more frequent clinical pictures were: pneumonia (39,7%) and bronchiolitis 25.8%; Case-fatality rate: 5.9% (44/741). Mortality risk factors were [RR (95%CI)]: neurological disease [5.00 (2.84-8.81)], genetic disease [3.67 (1.58-8.52)], malnutrition [3,07 (1.46-6.48)] and prematurity [2.28 (1.14-4.56)]. Independent mortality predictor: neurological disease [3.84 (1.81-8.14)]. No significant association between age, chronic respiratory disease, immunosuppression and viral co-infection with lethality was observed. CONCLUSIONS: Almost half of children with pH1N1 infection had underlying disease; the neurological condition was a separate CFR predictor.

Impacto de la vacuna neumocócica conjugada 13-valente en la incidencia de neumonía consolidante en menores de 5 anos en el partido de Pilar, Buenos Aires: estudio de base poblacional / Impact of the 13-valent pneumococcal conjugate vaccine on the incidence of consolidated pneumonia in children younger than 5 years old in Pilar, Buenos Aires: A population-based study

Introducción. En enero de 2012, en Argentina, fue introducida la vacuna neumocócica conjugada 13-valente (13-Valent Pneumococcal Conjugate Vaccine; PCV13, por sus siglas en inglés) en el Calendario Nacional, en menores de 2 anos. La cobertura en el partido de Pilar en 2012 fue > 90% para las primeras 2 dosis y 60% para la tercera. Objetivo. Medir la efectividad de la PCV13 en la reducción de la incidencia de neumonías consolidantes (NC), durante los dos anos siguientes a su introducción en el Calendario. Métodos. Estudio prospectivo debase poblacional en Pilar. Se incluyeron todos los menores de 5 anos con signos clínicos de neumonía atendidos en hospitales de referencia (ambulatorios y hospitalizados) en los primeros 2 anos de la incorporación (2012-2013). Se comparó la incidencia anual de NC con el período basal 2003-2005. Evaluación clínica-radiológica, según criterio de la Organización Mundial de la Salud. Resultados. Se incluyeron 666 pacientes con sospecha clínica de neumonía. Se diagnosticó NC en 309 pacientes; 52,1% de mujeres, 70,2% menores de 2 anos y 56,4% vacunado con PCV13; 4,5% (14/309) con bacteriología confirmada (S. pneumoniae: 4; N. meningitidis: 4; S. aureus: 2; otros: 4). Se observó una reducción significativa en la incidencia de NC (por 100000 niños menores de 5 anos) entre los períodos pre y posvacunal de 750 (204/27209) a 561 (171/30 475) en 2012 y 453 (138/30 475) en 2013; efectividad de 25,2% y 39,6%, respectivamente. Reducción en menores de 1 año: 33,9% en 2012 y 44,6% en 2013; y en niños de 12-23 meses: 57,9% en 2013. No se observaron diferencias significativas en las incidencias en edades mayores. Conclusiones. Luego de la introducción de la PCV13 en el Calendario de Vacunación en Argentina, se observó una reducción rápida y significativa en la incidencia de NC, principalmente en menores de 1 año en 2012 y menores de 2 anos en 2013.

Introduction. In January 2012, Argentina introduced the 13-valent pneumococcal conjugate vaccine (PCV13) in its immunization schedule for children younger than 2 years old. Coverage in Pilar in 2012 reached>90% for the first two doses and 60% for the third dose. Objective. To measure the effectiveness of PCV13 to reduce the incidence of consolidated pneumonia (CP)in the two-year period following its introduction in the immunization schedule. Methods. Prospective, population-based study conducted in Pilar. All children younger than 5 year sold with clinical signs of pneumonia assisted at the reference hospitals (both inpatients and utpatients) in the first two years since the vaccine introduction (2012-2013) were included. The annual incidence of CP was compared to the 2003-2005 baseline period. Clinical and radiological assessments were done as per the World Health Organization's criteria. Results. Six hundred and sixty-six patients with clinical suspicion of pneumonia were included. CP was diagnosed in 309 patients; 52.1% were girls, 70.2% were younger than 2 years old, and 56.4% had been immunized with the PCV13; 4.5% (14/309) had bacteriological confirmation (S. pneumoniae: 4; N. meningitidis: 4; S. aureus: 2; others: 4). A significant reduction in the incidence of CP (per 100 000 children younger than 5 years old) was observed between the pre- and postimmunization periods, from 750 (204/27209) to 561 (171/30 475) in 2012 and to 453 (138/30 475) in 2013; effectiveness accounted for 25.2% and 39.6%, respectively. Reduction in infants younger than 1 year old: 33.9% in 2012 and 44.6% in 2013; and in children aged 12-23 months old: 57.9% in 2013. No significant differences were observed in the incidence of CP at an older age. Conclusions. Following the introduction of PCV13 in Argentina's immunization schedule, a fast and significant reduction in the incidence of CP was observed, mainly in infants younger than 1 year old in 2012 and in children younger than 2 years old in 2013.

Virus respiratorio sincicial: Patrón clínico epidemiológico en niños internados en un hospital pediátrico durante los años 2000-2013 / Respiratory syncytial virus: Clinical and epidemiological pattern in pediatric patients admitted to a children's hospital between 2000 and 2013

Introducción. El virus respiratorio sincicial (VRS) es el principal agente asociado a infección respiratoria aguda baja en niños. El objetivo de este estudio fue describir el patrón clínico-epidemiológico e identificar los factores de riesgo de infección por VRS. Población y métodos. Estudio prospectivo de cohorte de pacientes internados por infección respiratoria aguda baja en el Hospital de Niños Ricardo Gutiérrez, marzo-noviembre, 20002013. El diagnóstico viral para VRS, adenovirus, influenza y parainfluenza se realizó por inmunofluorescencia indirecta de aspirados nasofaríngeos. Resultados. Se incluyeron 12 555 niños; 38,2% (4798) presentaron rescate viral; el VRS representó el 81,8% (3924/4798) sin variaciones anuales significativas (71,2-88,1), con patrón epidémico estacional (mayo-julio); fue seguido por influenza (7,6%), parainfluenza (5,9%) y adenovirus (4,7%). Los casos con rescate de VRS (3924) tuvieron una mediana de edad de 7 meses (0-214 meses); 74,2% eran menores de 1 año; 43,1%, menores de 6 meses; 56,5%, varones; y la manifestación clínica más frecuente fue bronquiolitis (60,7%). El 41,6% tenía comorbilidades; las más frecuentes, enfermedad respiratoria crónica (74%), cardiopatías congénitas (14%) y enfermedad neurológica crónica (10,2%). El 25% presentó complicaciones. La letalidad fue 1,9% (74/3888). Los predictores independientes de infección por VRS fueron la edad < 3 meses OR 2,8 (2,14-3,67), p < 0,01 , la bronquiolitis como presentación clínica OR 1,54 (1,32-1,79), p < 0,01 y la presencia de hipoxemia al momento del ingreso OR 1,84 (1,42-2,37), p < 0,01 . Conclusiones. La infección por VRS presentó un patrón epidémico estacional y se asoció más a niños pequeños menores de tres meses con bronquiolitis e hipoxemia al momento del ingreso.

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[Prescription and use of antibiotics at a pediatric intensive care unit in Buenos Aires City]. / Prescripción y uso de antibióticos en una unidad de cuidados intensivos pediátricos de la Ciudad de Buenos Aires.

INTRODUCTION: Antibiotics are the most prescribed drugs in pediatric intensive care units (PICU) with high impact in pathogens resistance and costs. OBJECTIVES: Evaluate prescription patterns and consumption of antibiotics. MATERIALS AND METHODS: From July 2006 to January 2007, monthly cross-sectional cuts were done on antibiotics use at the 1st and 7th days of prescription. A monthly antibiotics consumption average was then calculated. RESULTS: Of 81 patients, 41 received antibiotics, of which 34 were treated for at least seven days. INDICATORS: 1. Mean antibiotics / patient: 83 antibiotics were used at the initial empirical treatment (meropenem 18%, vancomycin 16.8%, amikacin 16.8%, cefotaxime 13.2%, ceftazidime 6%, clarithromycin 6%, piperacillin-tazobactam 4.8%, colistin 4.8%). mean: 2 antibiotics/patient. 98 antibiotics were used at the 7th day (vancomycin 17.3%, meropenem 16.3%, amikacin 9.8%, minocycline 9.8%, colistin 9.1%, amphotericin 6.1%, trimethoprim-sulfamethoxazole 4%, ceftazidime 5.1%). Mean: 2.8 antibiotics/patient. 2. Percentage of specimen obtained: Blood culture 100%, tracheal aspirate 68%, catheter culture 54.5% 3. Percentage of patients with positive culture: Pathogens were isolated in 56.1%, of which: Bacteria in 94.3%, Gram negative non fermenting strains, in 60.6%, Enterobacteriaceae in 24.2%, Gram positive cocci in 15% and Fungi in 5.7%. 4. Percentage of adjusted antibiotic scheme: 52%. 5. Percentage of interrupted antibiotics with negative culture: 22.2%. Monthly average of consumption was: meropenem 13.44; vancomycin 10.2; cefotaxime 3.6; ceftriaxone 2.20; piperacillin-tazobactam 7.38, amikacin 2.3. CONCLUSIONS: Vancomicyn and carbapenems were the antibiotics of greater use as initial empirical treatment. The initial empirical scheme would have to be adjusted to the microbiological results in order to obtain a more prudent antibiotic use.

Estudio de las enfermedades respiratorias por virus Influenza A H1N1 (pH1N1) en niños internados durante el año de la pandemia: Experiencia de 34 centros en la Argentina / Study of respiratory influenza A H1N1 Virus (pH1N1) in hospitalized children in the pandemic year: Experience in 34 centers in Argentina

Introducción. En la Argentina, la pandemia de Influenza A pH1N1 de 2009 provocó cerca de 10 000 casos confirmados con alto impacto en pediatría. Objetivos. Describir las características clínico epidemiológicas y analizar los factores de riesgo de letalidad en niños hospitalizados con infección confirmada por pH1N1. Población y métodos. Se identificaron todas las fichas de casos sospechosos (según Ministerio de Salud) internados en 34 centros y se incluyeron todos los casos confirmados de 0-18 años desde el 1/4/09 al 31/8/09 en un estudio de cohorte retrospectivo. El diagnóstico viral se confirmó por método RT-PCR. Los datos se expresaron en porcentajes, media, mediana, desvío estándar e intervalo intercuartilo (IIC) según correspondiera; y como medida de asociación, Riesgo Relativo (RR), con Intervalo de Confianza 95% (IC95%). Se realizó regresión logística múltiple para determinar los predictores independientes. Resultados. Número total de casos sospechosos: 2367; se realizó PCR al 47,8% (n: 1131) siendo positivos para pH1N1 65,5% (n: 741/1131); 57,2% varones; 61,5% <24 meses, mediana de edad: 14 meses (IIC 6-46 meses); 45,1% con enfermedad subyacente; formas clínicas de presentación más frecuentes: neumonía 39,7% y bronquiolitis 25,8%; letalidad: 5,9% (44/741). Factores de riesgo de letalidad [RR (IC95%)]: enfermedad neurológica [5,00 (2,84-8,81)], enfermedad genética [3,67 (1,58-8,52)], desnutrición [3,07 (1,46-6,48)] y prematurez [2,28 (1,14-4,56)]. Predictor independiente de letalidad: enfermedad neurológica [3,84 (1,81-8,14)]. No se observó asociación significativa entre edad, enfermedad respiratoria crónica, inmunosupresión y coinfección viral con la letalidad. Conclusiones. Casi la mitad de los niños con infección por pH1N1 tenía enfermedad subyacente; la enfermedad neurológica fue un predictor independiente de letalidad.

Introduction. In Argentina, pandemic influenza pH1N1 caused nearly 10,000 confirmed cases with high impact in pediatrics. Objectives. To describe clinical and epidemiological characteristics and analyse the risk factor of lethality in children hospitalized with infection pH1N1 confirmed by PCR Population and methods. We identified all suspected cases (according to Ministry of health) in 34 centers and we included all the confirmed cases of 0-18 years from 1/4/09 to 31/8/09 in a retrospective cohort study. The viral diagnosis was confirmed by RT-PCR method. Data are expres sed in percentages, average, median, standard deviation, and range (IQR) as appropriate; and as a measure of association, relative risk (RR), with 95% confidence interval (95%CI). Multiple logistic regression was conducted to determine the independent risk predictors. Results. Total number of suspected cases were: 2367; PCR was performed to 47.8% (n: 1131) being positive for pH1N1 65.5% (n: 741/1131); 57.2% males; 61.5% <24 months, median age: 14 months (IQR 6-46 months); 45.1% with underlying disease; more frequent clinical pictures were: pneumonia (39,7%) and bronchiolitis 25.8%; Case-fatality rate: 5.9% (44/741). Mortality risk factors were [RR (95%CI)]: neurological disease [5.00 (2.84-8.81)], genetic disease [3.67 (1.58-8.52)], malnutrition [3,07 (1.46-6.48)] and prematurity [2.28 (1.14-4.56)]. Independent mortality predictor: neurological disease [3.84(1.81-8.14)]. No significant association between age, chronic respiratory disease, immunosuppression and viral co-infection with lethality was observed. Conclusions. Almost half of children with pH1N1 infection had underlying disease; the neurological condition was a separate CFR predictor.