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1.
Cytokine ; 148: 155619, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34134910

RESUMEN

BACKGROUND: In children with cancer and persistent high-risk febrile neutropenia (HRFN), cytokines/chemokines profiles can guide the differentiation of febrile neutropenia (FN) due to infections and episodes of unknown origin (FN-UO). METHODS: A prospective, multicenter study in Santiago, Chile included patients ≤ 18 years with cancer and HRFN. Clinical and microbiological studies were performed according to validated protocols. Serum levels of 38 cytokines/chemokines were determined on day 4 of persistent HRFN. We performed comparisons between i) HRFN episodes with a detected etiological agent (FN-DEA) and FN-UO, and ii) bacterial versus viral infections. ROC curves were used to assess the discriminatory power of the analytes. RESULTS: 110 HRFN episodes were enrolled (median age 8 years, 53% female). Eighty-four patients were FN-DEA: 44 bacterial, 32 viral, and 8 fungal infections. Twenty-six cases were categorized as FN-UO. Both groups presented similar clinical and laboratory characteristics. Nineteen out of 38 analytes had higher concentrations in the FN-DEA versus FN-UO group. G-CSF, IL-6, and Flt-3L showed the highest discriminatory power to detect infection (AUC 0.763, 0.741, 0.701). Serum levels of G-CSF differentiated bacterial infections and IP-10 viral agents. A combination of G-CSF, IL-6, Flt-3L, and IP-10 showed an AUC of 0.839, 75% sensitivity, and 81% specificity. CONCLUSION: A specific immune response is present on day four of persistent HRFN in children with cancer. We propose a combined measure of serum concentrations of G-CSF, IL-6, IP-10, and Flt-3L, in order to predict the presence of an infectious agent as compared to an episode of FN with unknown origin.


Asunto(s)
Quimiocinas/sangre , Citocinas/sangre , Neutropenia Febril/sangre , Neoplasias/sangre , Niño , Neutropenia Febril/diagnóstico , Neutropenia Febril/microbiología , Neutropenia Febril/virología , Femenino , Humanos , Masculino , Curva ROC , Factores de Riesgo
2.
Rev. chil. infectol ; 37(6)dic. 2020.
Artículo en Español | LILACS | ID: biblio-1388182

RESUMEN

Resumen Introducción: La infección por virus SARS-CoV-2 responsable de la pandemia actual, es una entidad clínica y fisiopatológica nueva y en desarrollo, cuyo control aún es incierto mientras no contemos con una vacuna efectiva y de distribución universal. Descrita inicialmente como una enfermedad respiratoria mayoritariamente de adultos, los niños también pueden enfermar y se ha visto que en ellos las manifestaciones clínicas de enfermedad suelen diferir a las de los adultos expresándose como cuadros benignos en su mayoría. Si requieren hospitalización o algún tipo de asistencia, el cuadro se resuelve con tratamiento de soporte y sin complicaciones, mayoritariamente. Sin embargo, en el síndrome inflamatorio multisistémico asociado a COVID-19 (SIM-C) es de vital importancia la sospecha precoz y la derivación a un centro de alta complejidad para otorgar el soporte y tratamiento adecuado para lograr una buena y adecuada sobrevida. Objetivo: Describir el espectro clínico de enfermedad por virus SARS-CoV-2 en un centro de referencia pediátrico con la pandemia aún en desarrollo. Método: Se presenta la casuística de 537 pacientes con infección por SARS-CoV-2 atendidos entre marzo 1 y julio 15, 2020, con descripción de aquellos que fueran hospitalizados. Resultados: 127 (23%) de ellos fueron internados y de éstos 69% sintomáticos. Veintiséis pacientes (20%) de los hospitalizados presentaron SIM-C y sólo uno falleció por complicaciones de sus patologías de base.


Abstract Background: SARS-CoV-2 virus infection responsible for de pandemic in course, is a new clinical and physiopathological entity, whose control is still uncertain till we can provide an effective and universal vaccine. In the beginning it was described as a respiratory disease which affects mainly adults, children can have the disease too and in this group the disease can be different than the adult disease. Acute infection in children is mostly mild and when it requires hospital assistance it resolves with support therapy and without complications most of the time. However, in the Pediatric Inflammatory Multisystemic Syndrome is vital the early clinical suspect and refers to a tertiary center to bring support and properly treatment. Aim: To describe the clinical spectrum of SARS-CoV-2 virus disease in a pediatric referral center with the pandemic still in development. Method: A case series of 537 patients with SARS-CoV-2 infection treated between March 1 and July 15, 2020 is presented with a description of those who were hospitalized. Results: 127 (23%) of them were hospitalized and of these 69% were symptomatic. Twenty-six patients (20%) of those hospitalized presented PIMS, only one died for complications of his chronic diseases.


Asunto(s)
Niño , Humanos , COVID-19/epidemiología , Hospitalización/estadística & datos numéricos , Chile/epidemiología , Pandemias , Hospitales
3.
Rev. chil. infectol ; 37(4): 383-388, ago. 2020. tab
Artículo en Español | LILACS | ID: biblio-1138562

RESUMEN

Resumen Introducción: Streptococcus grupo viridans (SGV) ha adquirido relevancia como microorganismo causante de neutropenia febril, asociándose a morbilidad significativa. Objetivo: Caracterizar episodios de bacteriemia causados por SGV en niños con cáncer que desarrollaron neutropenia febril de alto riesgo (NFAR) desde abril de 2004 a junio de 2018 en seis hospitales pediátricos de Santiago, Chile. Pacientes y Métodos: Análisis retrospectivo de bases de datos de cuatro proyectos FONDECYT sucesivos, prospectivos y multicéntricos, registrando características clínicas y de laboratorio de los pacientes, además de patrón de resistencia antimicrobiana de las cepas aisladas. Resultados: Se registraron 95 episodios de bacteriemia asociada a SGV en 91 niños con NFAR. Destacan: leucemia mieloide aguda como enfermedad de base, neutropenia profunda, hospitalización prolongada (15 días), uso extendido de antimicrobianos (14 días), uso de citarabina en esquemas de quimioterapia (86% episodios). Las manifestaciones clínicas más frecuentes fueron respiratoria y gastrointestinal, asociándose en 26% a síndrome de shock por Streptococcus grupo viridans. Hubo elevada resistencia a β lactámicos, sin cepas no susceptibles a vancomicina. Discusión: SGV es un patógeno relevante en niños con cáncer, fiebre y neutropenia en nuestro medio, asociado a casos de sepsis. La resistencia a β lactámicos es un aspecto que requiere vigilancia epidemiológica estricta en esta población.


Abstract Background: Viridans group streptococci (VGS) has acquired relevance as a microorganism causing febrile neutropenia, associated with significant morbidity. Aim: To characterize episodes of bacteremia caused by VGS in children with cancer who developed high-risk febrile neutropenia (HRFN) during the period from April 2004 to June 2018 in six pediatric hospitals of Santiago, Chile. Method: Database analysis of 4 successive, prospective and multicentric studies recording clinical and laboratory characteristics of patients, as well as antimicrobial susceptibility pattern of isolated strains. Results: 95 episodes of VGS bacteremia in 91 children with HRFN were analyzed. It emphasizes acute myeloid leukemia as cancer type, deep neutropenia, prolonged hospitalization (15 days), with extended use of antimicrobials (14 days) and use of cytarabine in chemotherapy schemes (86% episodes). The most frequent clinical manifestations were respiratory and gastrointestinal, associating up to 26% viridans group shock syndrome. There was high resistance to β lactams. As expected, there were not non-susceptible strains to vancomycin. Discussion: VGS is a relevant microorganism in children with cancer, fever and neutropenia, with a high percentage of sepsis. Resistance to β lactams is an issue that requires strict epidemiological surveillance in this population.


Asunto(s)
Humanos , Niño , Infecciones Estreptocócicas/tratamiento farmacológico , Bacteriemia/tratamiento farmacológico , Neutropenia Febril/tratamiento farmacológico , Neoplasias/complicaciones , Neoplasias/tratamiento farmacológico , Chile/epidemiología , Estudios Prospectivos , Antibacterianos/uso terapéutico
4.
Mycoses ; 63(8): 802-811, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32347600

RESUMEN

BACKGROUND: Invasive fungal disease is a major cause of morbidity and mortality in children with cancer and high-risk febrile neutropenia (HRFN). Repeated serum galactomannan (sGM) measurements have been described as an effective tool to guide therapy in adults under suspicion of invasive aspergillosis. However, the utility of this approach has not been reported in paediatric population. OBJECTIVES: To evaluate the usefulness of sGM measurements in initiating and modifying antifungal therapy (AFT) in children with cancer and persistent HRFN. PATIENTS/METHODS: Nested case-control study in children with cancer and persistent HRFN episodes, between July 2013 and January 2019. Patients were classified as cases and controls depending on if they received AFT or not, respectively. Through odds ratio analysis, we assessed the role of sGM positivity in the AFT initiation decision. Then, we analysed the group of patients that initiated AFT, and compared those who had AFT modifications and those who did not, analysing different sGM kinetics thresholds. RESULTS: A total of 191 episodes from children with persistent HRFN were enrolled, of which 107 received AFT and 84 did not. The median age was 7 years (IQR 4-12), 52% were male and 89% had a haematologic malignancy as underlying disease. Positive sGM was not associated with AFT initiation (OR 0.99, 95% CI 0.43-2.33, P = .99). A difference threshold in sGM Δ ≥ 0.3 sGM was significantly associated with AFT modification (OR 5.07, 95% CI 1.02- 25.70, P = .04). CONCLUSIONS: Our results suggest the utility of serial sGM sampling during AFT in children with persistent HRFN.


Asunto(s)
Antifúngicos/uso terapéutico , Neutropenia Febril Inducida por Quimioterapia/complicaciones , Infecciones Fúngicas Invasoras/tratamiento farmacológico , Mananos/sangre , Neoplasias/complicaciones , Aspergilosis/tratamiento farmacológico , Estudios de Casos y Controles , Niño , Femenino , Galactosa/análogos & derivados , Neoplasias Hematológicas/complicaciones , Humanos , Aspergilosis Pulmonar Invasiva/tratamiento farmacológico , Masculino
5.
Rev Chilena Infectol ; 37(6): 756-761, 2020 12.
Artículo en Español | MEDLINE | ID: mdl-33844817

RESUMEN

BACKGROUND: SARS-CoV-2 virus infection responsible for de pandemic in course, is a new clinical and physiopathological entity, whose control is still uncertain till we can provide an effective and universal vaccine. In the beginning it was described as a respiratory disease which affects mainly adults, children can have the disease too and in this group the disease can be different than the adult disease. Acute infection in children is mostly mild and when it requires hospital assistance it resolves with support therapy and without complications most of the time. However, in the Pediatric Inflammatory Multisystemic Syndrome is vital the early clinical suspect and refers to a tertiary center to bring support and properly treatment. AIM: To describe the clinical spectrum of SARS-CoV-2 virus disease in a pediatric referral center with the pandemic still in development. METHOD: A case series of 537 patients with SARS-CoV-2 infection treated between March 1 and July 15, 2020 is presented with a description of those who were hospitalized. RESULTS: 127 (23%) of them were hospitalized and of these 69% were symptomatic. Twenty-six patients (20%) of those hospitalized presented PIMS, only one died for complications of his chronic diseases.


Asunto(s)
COVID-19/epidemiología , Hospitalización/estadística & datos numéricos , Niño , Chile/epidemiología , Hospitales , Humanos , Pandemias
6.
Rev Chilena Infectol ; 37(4): 383-388, 2020 Aug.
Artículo en Español | MEDLINE | ID: mdl-33399658

RESUMEN

BACKGROUND: Viridans group streptococci (VGS) has acquired relevance as a microorganism causing febrile neutropenia, associated with significant morbidity. AIM: To characterize episodes of bacteremia caused by VGS in children with cancer who developed high-risk febrile neutropenia (HRFN) during the period from April 2004 to June 2018 in six pediatric hospitals of Santiago, Chile. METHOD: Database analysis of 4 successive, prospective and multicentric studies recording clinical and laboratory characteristics of patients, as well as antimicrobial susceptibility pattern of isolated strains. RESULTS: 95 episodes of VGS bacteremia in 91 children with HRFN were analyzed. It emphasizes acute myeloid leukemia as cancer type, deep neutropenia, prolonged hospitalization (15 days), with extended use of antimicrobials (14 days) and use of cytarabine in chemotherapy schemes (86% episodes). The most frequent clinical manifestations were respiratory and gastrointestinal, associating up to 26% viridans group shock syndrome. There was high resistance to ß lactams. As expected, there were not non-susceptible strains to vancomycin. DISCUSSION: VGS is a relevant microorganism in children with cancer, fever and neutropenia, with a high percentage of sepsis. Resistance to ß lactams is an issue that requires strict epidemiological surveillance in this population.


Asunto(s)
Bacteriemia , Neutropenia Febril , Neoplasias , Infecciones Estreptocócicas , Antibacterianos/uso terapéutico , Bacteriemia/tratamiento farmacológico , Niño , Chile/epidemiología , Neutropenia Febril/tratamiento farmacológico , Humanos , Neoplasias/complicaciones , Neoplasias/tratamiento farmacológico , Estudios Prospectivos , Infecciones Estreptocócicas/tratamiento farmacológico
7.
J Antimicrob Chemother ; 73(10): 2860-2866, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-30010931

RESUMEN

Objectives: To compare the efficacy of pre-emptive versus empirical antifungal therapy in children with cancer, fever and neutropenia. Methods: This was a prospective, multicentre, randomized clinical trial. Children presenting with persistent high-risk febrile neutropenia at five hospitals in Santiago, Chile, were randomized to empirical or pre-emptive antifungal therapy. The pre-emptive group received antifungal therapy only if the persistent high-risk febrile neutropenia was accompanied by clinical, laboratory, imaging or microbiological pre-defined criteria. The primary endpoint was overall mortality at day 30 of follow-up. Secondary endpoints included invasive fungal disease (IFD)-related mortality, number of days of fever, days of hospitalization and use of antifungal drugs, percentage of children developing IFD, requiring modification of initial treatment strategy and need for ICU. The trial was registered with Registro Brasileiro de Ensaios Clínicos (ReBEC) under trial number RBR-3m9d74. Results: A total of 149 children were randomized, 73 to empirical therapy and 76 to pre-emptive therapy. Thirty-two out of 76 (42%) children in the pre-emptive group received antifungal therapy. The median duration of antifungal therapy was 11 days in the empirical arm and 6 days in the pre-emptive arm (P < 0.001), with similar overall mortality (8% in the empirical arm and 5% in the pre-emptive arm, P = 0.47). IFD-related mortality was the same in both groups (3%, P = 0.97), as were the percentage of children with IFD (12%, P = 0.92) and the number of days of fever (9, P = 0.76). The number of days of hospitalization was 19 in the empirical arm and 17 in the pre-emptive arm (P = 0.15) and the need for ICU was 25% in the empirical arm and 20% in the pre-emptive arm (P = 0.47). Conclusions: Pre-emptive antifungal therapy was as effective as empirical antifungal therapy in children with cancer, fever and neutropenia, significantly reducing the use of antifungal drugs.


Asunto(s)
Antifúngicos/uso terapéutico , Quimioprevención/métodos , Neutropenia Febril/complicaciones , Infecciones Fúngicas Invasoras/tratamiento farmacológico , Infecciones Fúngicas Invasoras/prevención & control , Neoplasias/complicaciones , Neoplasias/terapia , Niño , Preescolar , Chile , Femenino , Humanos , Infecciones Fúngicas Invasoras/mortalidad , Tiempo de Internación , Masculino , Estudios Prospectivos , Análisis de Supervivencia , Resultado del Tratamiento
8.
Rev Chilena Infectol ; 35(2): 140-146, 2018 04.
Artículo en Español | MEDLINE | ID: mdl-29912251

RESUMEN

BACKGROUND: Microorganisms isolated from blood cultures (BC) in patients with febrile neutropenia (NF) vary over time, requiring systematic monitoring to guide appropriate empirical therapy. AIM: To identify microorganisms isolated from BC and their antimicrobial resistance profile in children with cancer and high risk NF. METHOD: Prospective, multicenter study. The analysis included episodes of high-risk FN with positive BC in children under 18 years of age treated in five hospitals in Santiago, Chile, 2012-2015. RESULTS: A total of 206 microorganisms were analyzed in 185 episodes of high-risk FN. The main isolates were Gram negative bacilli (46.6%) and Gram positive cocci (45.1%) and the most frequent microorganisms were Escherichia coli (22.8%), coagulase negative Staphylococcus (18.0%) and Klebsiella spp. (16.5%). Escherichia coli and Klebsiella spp showed 4.2% and 67.6% resistance to third generation cephalosporins (cefotaxime/ceftriaxone), 10.6% and 40.6% resistance to fluoroquinolones (ciprofloxacin) and 2.1% and 26.5% to amikacin, respectively. Coagulase negative Staphylococcus and Staphylococcus aureus had 86.4% and 22.2% resistance to oxacillin, Streptococcus viridans group had 71% resistance to penicillin. DISCUSSION: This study updates the etiology and resistance profile of microorganisms isolated in BC from children with cancer and high risk FN, an essential tool for the adequate management of these patients.


Asunto(s)
Farmacorresistencia Bacteriana , Neutropenia Febril/microbiología , Bacterias Gramnegativas/aislamiento & purificación , Bacterias Grampositivas/aislamiento & purificación , Neoplasias/microbiología , Antibacterianos/farmacología , Niño , Chile , Femenino , Bacterias Gramnegativas/clasificación , Bacterias Grampositivas/clasificación , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Neoplasias/complicaciones , Estudios Prospectivos
9.
Rev. chil. infectol ; 35(2): 140-146, abr. 2018. tab, graf
Artículo en Español | LILACS | ID: biblio-959423

RESUMEN

Resumen Antecedentes: Los microorganismos aislados de hemocultivos (HC) en pacientes con neutropenia febril (NF) varían en el tiempo, siendo necesaria su vigilancia para orientar una terapia empírica adecuada. Objetivo: Identificar microorganismos aislados de HC y su perfil de resistencia (R) a antimicrobianos en niños con cáncer y NF de alto riesgo. Método: Estudio prospectivo, multicéntrico de episodios de NF de alto riesgo en pacientes bajo 18 años de edad, de cinco hospitales en Santiago de Chile, 2012-2015. Análisis de HC positivos. Resultados: Se analizaron 206 microorganismos en 185 episodios de NF de alto riesgo con HC positivos. Los aislados principales fueron bacilos gramnegativos (BGN) (46,6%) y cocáceas grampositivas (CGP) (45,1%) y los microorganismos más frecuentes Escherichia coli (22,8%), Staphylococcus coagulasa negativa (18,0%) y Klebsiella spp (16,5%). En resistencia (R) a antimicrobianos destaca: E. coli y Klebsiella spp 4,2 y 67,6% R a cefalosporinas de tercera generación (cefotaxima/ceftriaxona) respectivamente, 10,6 y 40,6% R a ciprofloxacina y 2,1 y 26,5% a amikacina, respectivamente. S. coagulasa negativa y S. aureus 86,4% y 22,2% R a oxacilina, Streptococcus grupo viridans 71% R a penicilina. Discusión: Este estudio actualiza la etiología y el perfil de R de microorganismos aislados en HC de niños con cáncer y NF de alto riesgo, herramienta esencial para el adecuado manejo de estos pacientes.


Background: Microorganisms isolated from blood cultures (BC) in patients with febrile neutropenia (NF) vary over time, requiring systematic monitoring to guide appropriate empirical therapy. Aim: To identify microorganisms isolated from BC and their antimicrobial resistance profile in children with cancer and high risk NF. Method: Prospective, multicenter study. The analysis included episodes of high-risk FN with positive BC in children under 18 years of age treated in five hospitals in Santiago, Chile, 2012-2015. Results: A total of 206 microorganisms were analyzed in 185 episodes of high-risk FN. The main isolates were Gram negative bacilli (46.6%) and Gram positive cocci (45.1%) and the most frequent microorganisms were Escherichia coli (22.8%), coagulase negative Staphylococcus (18.0%) and Klebsiella spp. (16.5%). Escherichia coli and Klebsiella spp showed 4.2% and 67.6% resistance to third generation cephalosporins (cefotaxime/ceftriaxone), 10.6% and 40.6% resistance to fluoroquinolones (ciprofloxacin) and 2.1% and 26.5% to amikacin, respectively. Coagulase negative Staphylococcus and Staphylococcus aureus had 86.4% and 22.2% resistance to oxacillin, Streptococcus viridans group had 71% resistance to penicillin. Discussion: This study updates the etiology and resistance profile of microorganisms isolated in BC from children with cancer and high risk FN, an essential tool for the adequate management of these patients.


Asunto(s)
Humanos , Masculino , Femenino , Niño , Farmacorresistencia Bacteriana , Neutropenia Febril/microbiología , Bacterias Gramnegativas/aislamiento & purificación , Bacterias Grampositivas/aislamiento & purificación , Neoplasias/microbiología , Pruebas de Sensibilidad Microbiana , Chile , Estudios Prospectivos , Bacterias Gramnegativas/clasificación , Bacterias Grampositivas/clasificación , Antibacterianos/farmacología , Neoplasias/complicaciones
10.
J Pediatr Hematol Oncol ; 38(5): 372-7, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27164527

RESUMEN

OBJECTIVE: The aim of this study was to analyze the survival of children with Wilms tumor and other malignant renal tumors treated with the TWPINDA-99 protocol. MATERIALS AND METHODS: Between January 1999 and December 2013, 226 patients were registered on this trial, based on National Wilms Tumor Study-5. Patient characteristics and survival were evaluated. RESULTS: Two hundred seven patients were diagnosed with Wilms tumor, which represented 91.6% of renal tumors. The male to female ratio was 0.7:1. The median age at diagnosis was 3.3 years. Stage III was the most frequent (39.2%). Metastatic disease was present in 16.7% of the cases. Synchronous bilateral disease was observed in 9.3% of the cases. Favorable histology was diagnosed in 93.6% and anaplastic histology in 6.4% of the patients. Median follow-up was 7.5 years. Ten-year event-free survival and overall survival (OS) for assessable patients with Wilms tumor (n=192) were 82.0% and 89.9%, respectively. OS for patients with stage I was 100% (n=36), stage II: 97.1% (n=35), stage III: 88.6% (n=71), stage IV: 77.9% (n=32), and stage V: 80.8% (n=18). OS for favorable histology (n=180) and anaplastic histology tumors (n=12) were 91.0% and 72.9%, respectively. Other malignant renal tumors had a poorer survival. CONCLUSION: Prognosis for patients with Wilms tumor treated on TWPINDA-99 seems to be better than previous national trials and is similar to developed countries.


Asunto(s)
Neoplasias Renales/terapia , Tumor de Wilms/terapia , Adolescente , Niño , Preescolar , Chile , Países Desarrollados , Supervivencia sin Enfermedad , Femenino , Humanos , Lactante , Recién Nacido , Neoplasias Renales/mortalidad , Masculino , Programas Nacionales de Salud/normas , Estadificación de Neoplasias , Pediatría , Tasa de Supervivencia , Resultado del Tratamiento , Tumor de Wilms/mortalidad
11.
J AAPOS ; 18(6): 617-9, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25448150

RESUMEN

Intra-arterial chemotherapy (IAC) has proved to be an effective treatment for retinoblastoma, but can be very expensive in developing countries. We report 2 patients from Chile in whom IAC resulted in globe salvation. Both patients had their medical care provided by the public health system and had failed standard therapy.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/economía , Análisis Costo-Beneficio , Infusiones Intraarteriales/economía , Neoplasias de la Retina/tratamiento farmacológico , Retinoblastoma/tratamiento farmacológico , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Chile , Países en Desarrollo , Costos de los Medicamentos , Humanos , Lactante , Masculino , Melfalán/administración & dosificación , Neoplasias de la Retina/patología , Retinoblastoma/patología , Topotecan/administración & dosificación
12.
Rev Chilena Infectol ; 31(3): 333-8, 2014 Jun.
Artículo en Español | MEDLINE | ID: mdl-25146209

RESUMEN

INTRODUCTION: Leukemia is the most common cancer in Chilean children. Acute lymphoblastic leukemia (ALL) is more prevalent and longer survival compared to acute myeloid leukemia (AML). AIMS: To describe episodes of febrile neutropenia (FN) in children with AML, determining frequency of infections as agent, focus and evolution, comparing children with ALL episodes. METHOD: A prospective multicenter study. Children presenting with FN at six hospitals in Santiago, Chile, were invited to participate in two consecutive FONDECYT projects, from April 2004 to June 2011. All patients were uniformly evaluated, recording epidemiological, clinical and laboratory variables. Information regarding FN episodes of children with LMA and LLA was used to this study. RESULTS: We evaluated 506 episodes of FN in children with leukemia: 173 children with AML and 333 in children with ALL. NF episodes in children with ALML showed significantly greater depth and duration of neutropenia, febrile remained a > period of time and had a worse clinical outcome, as evidenced by > hemodynamic instability, > sepsis, CRP > 90 mg/L for a longer time, more days of hospitalization, > frequency of hospitalization in ICU, > bacteremia, mainly by Streptococcus viridans group, > change of antimicrobial treatment, > use of antifungal therapy. CONCLUSIONS: This study demonstrates that FN episodes in children with ALML further evolve unfavorably, compared with episodes of FN in children with ALL. FN episodes in children with ALML require a more aggressive diagnostic and therapeutic approach, related to its severity.


Asunto(s)
Neutropenia Febril/etiología , Leucemia Mieloide Aguda/complicaciones , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaciones , Niño , Neutropenia Febril/tratamiento farmacológico , Humanos , Estudios Prospectivos , Índice de Severidad de la Enfermedad
13.
Rev. chil. infectol ; 31(3): 333-338, jun. 2014. ilus, tab
Artículo en Español | LILACS | ID: lil-716985

RESUMEN

Introduction: Leukemia is the most common cancer in Chilean children. Acute lymphoblastic leukemia (ALL) is more prevalent and longer survival compared to acute myeloid leukemia (AML). Aims: To describe episodes of febrile neutropenia (FN) in children with AML, determining frequency of infections as agent, focus and evolution, comparing children with ALL episodes. Method: A prospective multicenter study. Children presenting with FN at six hospitals in Santiago, Chile, were invited to participate in two consecutive FONDECYT projects, from April 2004 to June 2011. All patients were uniformly evaluated, recording epidemiological, clinical and laboratory variables. Information regarding FN episodes of children with LMA and LLA was used to this study. Results: We evaluated 506 episodes of FN in children with leukemia: 173 children with AML and 333 in children with ALL. NF episodes in children with ALML showed significantly greater depth and duration of neutropenia, febrile remained a > period of time and had a worse clinical outcome, as evidenced by > hemodynamic instability, > sepsis, CRP > 90 mg/L for a longer time, more days of hospitalization, > frequency of hospitalization in ICU, > bacteremia, mainly by Streptococcus viridans group, > change of antimicrobial treatment, > use of antifungal therapy. Conclusions: This study demonstrates that FN episodes in children with ALML further evolve unfavorably, compared with episodes of FN in children with ALL. FN episodes in children with ALML require a more aggressive diagnostic and therapeutic approach, related to its severity.


Introducción: En Chile, la leucemia es el cáncer más frecuente en niños, siendo las dos principales leucemia linfoblástica aguda (LLA) y leucemia mieloide aguda (LMA). Objetivo: Describir los episodios de neutropenia febril (NF) observados en niños con LMA, determinando la frecuencia de infecciones según agente, foco y evolución, comparándolos con episodios de niños con LLA. Método: Estudio prospectivo, multicéntrico. Pacientes < de 18 años con NF que consultaron en uno de los seis hospitales del grupo PINDA de Santiago, Chile (abril de 2004-junio de 2011), enrolados en dos sucesivos proyectos FONDECYT. Se recogió de manera sistemática la información epidemiológica, clínica y de laboratorio relativa a cada episodio de NF; posteriormente se extrajo de la base de datos la información correspondiente a los pacientes con LMA y LLA. Resultados: Se evaluaron 506 episodios de NF en niños con leucemia: 173 en niños con LMA y 333 en niños con LLA. Los episodios de NF en niños con LMA presentaron significativamente mayor duración e intensidad de la neutropenia, se mantuvieron febriles por un mayor período de tiempo y presentaron una peor evolución clínica, evidenciada por mayor inestabilidad hemodinámica, mayor frecuencia de sepsis, PCR > 90 mg/L por un período más prolongado, más días de hospitalización, mayor frecuencia de hospitalización en UCI, mayor presencia de bacteriemia, principalmente por Streptococcus grupo viridans, mayor número de cambio de esquemas antimicrobianos y mayor uso de antifúngicos, particularmente de tipo empírico. Conclusiones: Este estudio demuestra que los episodios de NF en niños con LMA evolucionan en mayor medida en forma desfavorable, comparado con episodios de NF en niños con LLA. Los episodios de NF en niños con LMA requieren un enfoque diagnóstico y terapéutico más agresivo, relacionado a su gravedad.


Asunto(s)
Niño , Humanos , Neutropenia Febril/etiología , Leucemia Mieloide Aguda/complicaciones , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaciones , Neutropenia Febril/tratamiento farmacológico , Estudios Prospectivos , Índice de Severidad de la Enfermedad
14.
Pediatr Infect Dis J ; 32(12): 1318-23, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24569305

RESUMEN

BACKGROUND: We previously created a risk prediction model for severe sepsis not clinically apparent during the first 24 hours of hospitalization in children with high-risk febrile neutropenia (HRFN), which identified 3 variables, age ≥ 12 years, serum C-reactive protein (CRP) ≥ 90 mg/L and interleukin-8 ≥ 300 pg/mL, evaluated at the time of admission and at 24 hours of hospitalization. The combination of these 3 variables identified a risk for severe sepsis ranging from 8% to 73% with a relative risk of 3.15 (95% confidence interval: 1.1-9.06). The aim of this study was to validate prospectively our risk prediction model for severe sepsis in a new cohort of children with cancer and HRFN. METHODS: Predictors of severe sepsis identified in our previous model (age, CRP and interleukin-8) were evaluated at admission and at 24 hours of hospitalization in a new cohort of children with HRFN between April 2009 and July 2011. Diagnosis of severe sepsis, not clinically apparent during the first 24 hours of hospitalization, was made after discharge by a blind evaluator. RESULTS: A total of 447 HRFN episodes were studied, of which 76 (17%) had a diagnosis of severe sepsis. The combination of age ≥ 12 years, CRP ≥ 90 mg/L and interleukin-8 ≥ 300 pg/mL at admission and/or at 24 hours in the new cohort identified a risk for severe sepsis ranging from 7% to 46% with an RR of 6.7 (95% CI: 2.3-19.5). CONCLUSIONS: We validated a risk prediction model for severe sepsis applicable to children with HRFN episodes within the first 24 hours of admission. We propose to incorporate this model in the initial patient assessment to offer a more selective management for children at risk for severe sepsis.


Asunto(s)
Neutropenia Febril Inducida por Quimioterapia/epidemiología , Modelos Estadísticos , Neoplasias/epidemiología , Sepsis/epidemiología , Adolescente , Proteína C-Reactiva/análisis , Neutropenia Febril Inducida por Quimioterapia/microbiología , Neutropenia Febril Inducida por Quimioterapia/patología , Niño , Preescolar , Femenino , Humanos , Interleucina-8/sangre , Masculino , Neoplasias/sangre , Neoplasias/tratamiento farmacológico , Riesgo , Sepsis/sangre
15.
Rev. chil. infectol ; 29(6): 595-599, dic. 2012. graf, tab
Artículo en Español | LILACS | ID: lil-665562

RESUMEN

Infections with varicella-zoster virus (VVZ) in immunocompromised children imply a high mortality. There is no data about VVZ seroprevalence in children with cancer in our country. Aim: To determine the prevalence of VVZ antibodies in children with cancer who have undergone chemotherapy or have undergone a hematopoietic stem cell transplant. Methodology: collaborative, multicenter study. Serum samples were collected from 281 children with cancer and episodes of febrile neutropenia from 6 hospitals belonging to the public health network in the Metropolitan Region between June 2004 and August 2006. These samples were stored at -70 ° C, and 200 of them were randomly chosen and analyzed to determine VVZ IgG (ELISA). Results: 179 samples from 179 children, 65% male. Ninety eigth/179 (55%) were positive, 72/179 (40%) negative and 9/179 (5%) indeterminate. Stratified by age, seropositive percentage was: 1 to 4 years 32%, 5-9 years 42%, 10-14 years 78%, over 15 years 88%. Conclusion: Forty percent of children treated for cancer are seronegative to VVZ infection, a frequency that decreases with age. These results support the adoption of preventive measures to avoid infection in this population of children at risk of developing a serious and possibly fatal illness.


Las infecciones por virus varicela-zoster (VVZ) en niños inmunocomprometidos presentan una alta morbi-mortalidad. Se desconoce la seroprevalencia de VVZ en niños con cáncer en nuestro medio. Objetivo: Determinar la prevalencia de anticuerpos anti VVZ en niños sometidos a tratamiento por cáncer (quimioterapia o trasplante de precursores hematopoyéticos). Método: Estudio colaborativo, multicéntrico. Se recolectaron muestras de suero de 281 niños con cáncer y episodios de neutropenia febril (NF) en seis hospitales de Santiago, entre junio 2004 y agosto 2006 y almacenadas a -70° Cº. Doscientas muestras fueron seleccionadas al azar para determinación de IgG anti VVZ. Resultados: De las 200 muestras de suero obtenidas se excluyeron 21: 12 por ser muestras de un mismo paciente en diferentes episodios de NF y 9 por falta de información. Se analizaron las muestras de 179 niños, 65% de sexo masculino. Noventa y ocho resultaron positivos (55%), 72 negativos (40%) y 9 indeterminados (5%). Estratificado por edad: 1-4 años (32%), 5-9 años (42%), 10-14 años (78%) y mayores de 15 años (88%). Conclusión: 40% de los niños en tratamiento por cáncer son seronegativos para VVZ, condición que disminuye en pacientes con mayor edad. Estos resultados apoyan la adopción de medidas que eviten la infección en esta población de niños con riesgo de desarrollar una enfermedad grave y eventualmente fatal.


Asunto(s)
Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Varicela/epidemiología , /inmunología , Huésped Inmunocomprometido/inmunología , Neoplasias/inmunología , Anticuerpos Antivirales/sangre , Varicela/diagnóstico , Varicela/inmunología , Chile/epidemiología , Ensayo de Inmunoadsorción Enzimática , Prevalencia , Estudios Seroepidemiológicos
16.
Rev Chilena Infectol ; 29(3): 329-34, 2012 Jun.
Artículo en Español | MEDLINE | ID: mdl-23096474

RESUMEN

INTRODUCTION: Lung infections are a serious complication in children with cancer. Bronchoalveolar lavage (BAL) has been demonstrated to be an effective procedure for achieving etiologic diagnosis. METHOD: We did a retrospective analysis of BAL data performed between November 2005 and October 2008 in children with cancer, severe neutropenia and lung infiltrates for assessing its performance, clinical utility and safety. Thirty-seven BAL were evaluated in 35 patients. RESULTS: Focal infiltrates were demonstrated in imaging studies associated with 19/37 BAL; in 8 an infectious agent was found. Interstitial pattern was observed in 15/37, in which there were 4 positive studies, proving a higher microbiological performance in BAL associated with focal lesions. BAL yielded significant microbiological findings in 32.4% (12/37). Sixteen microorganisms were identified in the study: bacteria in 8 cases, Mycobacterium tuberculosis (n: 2), Pseudomonas aeruginosa (n: 2), Acinetobacter baumannii (n: 1), A. Iwoffii (n: 1), group viridans Streptococcus (n: 1), Mycoplasma pneumoniae (n: 1); viruses in 3 cases, metapneumovirus (n: 2) cytomegalovirus (n: 1) and fungal infection in 5 cases, Pneumocystis jiroveci (n: 2) Aspergillus fumigatus (n: 1), Aspergillus niger (n: 1), Candida albicans (n: 1). Therapeutic adjustments were done in 6/37 episodes (16.2%). CONCLUSION: BAL has a significant role in the evaluation of pulmonary infiltrates in pediatric oncological patients, requiring a prompt and safe diagnosis, which is crucial for the survival with minimal morbidity. Our results suggest that BAL by fiberbronchoscopy should be considered as an initial diagnostic tool in these patients.


Asunto(s)
Antineoplásicos/efectos adversos , Líquido del Lavado Bronquioalveolar/microbiología , Neutropenia Febril Inducida por Quimioterapia/microbiología , Pulmón/diagnóstico por imagen , Pulmón/microbiología , Adolescente , Lavado Broncoalveolar , Broncoscopía , Niño , Preescolar , Femenino , Humanos , Lactante , Enfermedades Pulmonares/diagnóstico por imagen , Enfermedades Pulmonares/microbiología , Masculino , Neoplasias/tratamiento farmacológico , Estudios Prospectivos , Radiografía
17.
Rev Chilena Infectol ; 29(2): 156-62, 2012 Apr.
Artículo en Español | MEDLINE | ID: mdl-22689029

RESUMEN

INTRODUCTION: To determine the etiology of invasive bacterial infection in high risk febrile neutropenia (HRFN) episodes in children with cancer is essential because of the favorable impact on mortality of the early empiric antibiotic treatment. OBJECTIVE: To determine the etiology of bacteremia in pediatric patients with cancer and HRFN in the National Child Program of Antineoplastic Drugs during the 2004-2009 period, and compare these agents and their antimicrobial susceptibility with the period 1994-1998 described in a previous study. METHODS: The causative agents of bacteremia were prospectively recorded in patients less than 18 years of age receiving chemotherapy for cancer with HRFN and positive blood cultures admitted to one of the six hospitals from the Child Program of Antineoplastic Drugs network during the period 2004-2009. RESULTS: 839 episodes of HRFN were identified; 181 blood cultures were positive in the following proportion: gram positive cocci (56%), gram negative bacilli (42%) and yeast (2%).The most common etiologic agents were Staphylococcus coagulase negative (25%), Escherichia. coli (20%), group viridans Streptococcus (14%), Staphylococcus aureus (13%) and Pseudomonas aeruginosa (9%). Comparing the two periods, the relative frequency of Streptococcus spp increased from 4 to 17%, coagulase negative Staphylococcus decreased from 44 to 25%, showing an increase in their resistance to oxacillin from 55% to 77%. CONCLUSIONS: We describe the main etiological agents from HRFN episodes in children with cancer in a 5 years period. This information could help for a better approach in the empirical antimicrobial therapy in this population.


Asunto(s)
Bacteriemia/microbiología , Fiebre/microbiología , Bacterias Gramnegativas/clasificación , Bacterias Grampositivas/clasificación , Neoplasias/microbiología , Neutropenia/microbiología , Adolescente , Antibacterianos/farmacología , Niño , Chile , Femenino , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/aislamiento & purificación , Bacterias Grampositivas/efectos de los fármacos , Bacterias Grampositivas/aislamiento & purificación , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Estudios Prospectivos
18.
Rev. chil. infectol ; 29(3): 329-334, jun. 2012. tab
Artículo en Español | LILACS | ID: lil-645600

RESUMEN

Introduction: Lung infections are a serious complication in children with cancer. Bronchoalveolar lavage (BAL) has been demonstrated to be an effective procedure for achieving etiologic diagnosis. Method: We did a retrospective analysis of BAL data performed between November 2005 and October 2008 in children with cancer, severe neutropenia and lung infiltrates for assessing its performance, clinical utility and safety. Thirty-seven BAL were evaluated in 35 patients. Results: Focal infiltrates were demonstrated in imaging studies associated with 19/37 BAL; in 8 an infectious agent was found. Interstitial pattern was observed in 15/37, in which there were 4 positive studies, proving a higher microbiological performance in BAL associated with focal lesions. BAL yielded significant microbiological findings in 32.4% (12/37). Sixteen microorganisms were identified in the study: bacteria in 8 cases, Mycobacterium tuberculosis (n: 2), Pseudomonas aeruginosa (n: 2), Acinetobacter baumannii (n: 1), A. Iwoffii (n: 1), group viridans Streptococcus (n: 1), Mycoplasma pneumoniae (n: 1); viruses in 3 cases, metapneumovirus (n: 2) cytomegalovirus (n: 1) and fungal infection in 5 cases, Pneumocystis jiroveci (n: 2) Aspergillus fumigatus (n: 1), Aspergillus niger (n: 1), Candida albicans (n: 1). Therapeutic adjustments were done in 6/37 episodes (16.2%). Conclusion: BAL has a significant role in the evaluation of pulmonary infiltrates in pediatric oncological patients, requiring a prompt and safe diagnosis, which is crucial for the survival with minimal morbidity. Our results suggest that BAL by fiberbronchoscopy should be considered as an initial diagnostic tool in these patients.


Las infecciones pulmonares en niños con cáncer son una complicación grave. El lavado broncoalveolar (LBA) es un procedimiento efectivo para llegar a un diagnóstico etiológico. Se analizaron los resultados de LBA realizados entre noviembre de 2005 y octubre de 2008, en niños con cáncer y neutropenia grave e infiltrados pulmonares para conocer su rendimiento, utilidad clínica y seguridad. Se evaluaron 37 LBA en 35 pacientes. En 19/37 casos los infiltrados radiológicos fueron focales, en 8 se encontró etiología por LBA. En 15/37 casos las imágenes fueron intersticiales encontrándose etiología en 4, resultando un rendimiento microbiológico superior en las lesiones focales. Las muestras del LBA fueron positivas en 32,4% de los episodios (12/37). Se detectaron 16 microorganismos: 8 bacterias, a saber Mycobacterium tuberculosis (n: 2), Pseudomonas aeruginosa (n: 2), Acinetobacter baumannii (n: 1), A. Iwoffii (n: 1), Streptococcus grupo viridans (n: 1) y Mycoplasma pneumoniae (n: 1); 3 virus: metapneumovirus (n: 2) y citomegalovirus (n: 1); 5 hongos: Pneumocystis jiroveci (n: 2), Aspergillus fumigatus (n: 1), Aspergillus niger (n: 1) y Candida albicans (n: 1). Se reportaron cambios en la conducta terapéutica en 6 de 37 pacientes (16,2%) con inicio de nuevas terapias o suspensión de tratamientos empíricos. El LBA tuvo un adecuado rendimiento, sin complicaciones importantes por lo que debe ser considerado precozmente y realizado con un estudio protocolizado.


Asunto(s)
Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Antineoplásicos/efectos adversos , Líquido del Lavado Bronquioalveolar/microbiología , Neutropenia Febril Inducida por Quimioterapia/microbiología , Pulmón/microbiología , Pulmón , Lavado Broncoalveolar , Broncoscopía , Enfermedades Pulmonares/microbiología , Enfermedades Pulmonares , Neoplasias/tratamiento farmacológico , Estudios Prospectivos
19.
Rev. chil. infectol ; 29(2): 156-162, abr. 2012. graf, tab
Artículo en Español | LILACS | ID: lil-627228

RESUMEN

Introduction: To determine the etiology of invasive bacterial infection in high risk febrile neutropenia (HRFN) episodes in children with cancer is essential because of the favorable impact on mortality of the early empiric antibiotic treatment. Objective: To determine the etiology of bacteremia in pediatric patients with cancer and HRFN in the National Child Program of Antineoplastic Drugs during the 2004-2009 period, and compare these agents and their antimicrobial susceptibility with the period 1994-1998 described in a previous study. Methods: The causative agents of bacteremia were prospectively recorded in patients less than 18 years of age receiving chemotherapy for cancer with HRFN and positive blood cultures admitted to one of the six hospitals from the Child Program of Antineoplastic Drugs network during the period 2004-2009. Results: 839 episodes of HRFN were identified; 181 blood cultures were positive in the following proportion: gram positive cocci (56%), gram negative bacilli (42%) and yeast (2%).The most common etiologic agents were Staphylococcus coagulase negative (25%), Escherichia. coli (20%), group viridans Streptococcus (14%), Staphylococcus aureus (13%) and Pseudomonas aeruginosa (9%). Comparing the two periods, the relative frequency of Streptococcus spp increased from 4 to 17%, coagulase negative Staphylococcus decreased from 44 to 25%, showing an increase in their resistance to oxacillin from 55% to 77%. Conclusions: We describe the main etiological agents from HRFN episodes in children with cancer in a 5 years period. This information could help for a better approach in the empirical antimicrobial therapy in this population.


Introducción: Conocer la etiología de los episodios de neutropenia febril de alto riesgo (NFAR) en pacientes con cáncer tiene importancia para implementar tratamientos antimicrobianos ajustados a la epidemiología local, lo que tiene impacto en la morbilidad y mortalidad. Objetivo: Describir la etiología de las bacteriemias en niños con cáncer y NFAR en el período 2004-2009, en la red PINDA de Santiago (Región Metropolitana), Chile, y comparar estos agentes y su susceptibilidad antimicrobiana con un estudio previo realizado en el período 1994-1998. Material y Métodos: Se registraron prospectivamente los agentes causantes de bacteriemia y su susceptibilidad a antimicrobianos de los pacientes bajo 18 años de edad en tratamiento quimioterápico por cáncer, ingresados con diagnóstico de NFAR a los seis hospitales de la red, durante el período 2004-2009. Resultados: De 839 episodios de NFAR, 181 tuvieron hemocultivos positivos, correspondientes a cocáceas grampositivas (56%), bacilos gramnegativos (42%) y levaduras (2%). Los agentes más frecuentemente aislados fueron: Staphylococcus coagula-sa negativa (25%), Escherichia coli (20%), Streptococcus grupo viridans (14%), Staphylococcus aureus (13%) y Pseudomonas spp (9%). Al comparar los dos períodos de tiempo, destacan los siguientes cambios significativos: disminución en frecuencia relativa de Staphylococcus coagulasa negativa (desde 44 a 25%), aumento de Streptococcus spp (desde 4 a 17%), y aumento de la resistencia de Staphylococcus coagulasa negativa a oxacilina (desde 55 a 77%). Conclusiones: Se dan a conocer los principales agentes etiológicos de los episodios de NFAR y la susceptibilidad a antimicrobianos en un período de cinco años. Esto permite racionalizar el manejo antimicrobiano empírico de los episodios de NFAR en esta población.


Asunto(s)
Adolescente , Niño , Femenino , Humanos , Masculino , Bacteriemia/microbiología , Fiebre/microbiología , Bacterias Gramnegativas/clasificación , Bacterias Grampositivas/clasificación , Neoplasias/microbiología , Neutropenia/microbiología , Antibacterianos/farmacología , Chile , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/aislamiento & purificación , Bacterias Grampositivas/efectos de los fármacos , Bacterias Grampositivas/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Estudios Prospectivos
20.
Rev Chilena Infectol ; 29(6): 595-9, 2012 Dec.
Artículo en Español | MEDLINE | ID: mdl-23412026

RESUMEN

UNLABELLED: Infections with varicella-zoster virus (VVZ) in immunocompromised children imply a high mortality. There is no data about VVZ seroprevalence in children with cancer in our country. AIM: To determine the prevalence of VVZ antibodies in children with cancer who have undergone chemotherapy or have undergone a hematopoietic stem cell transplant. METHODOLOGY: collaborative, multicenter study. Serum samples were collected from 281 children with cancer and episodes of febrile neutropenia from 6 hospitals belonging to the public health network in the Metropolitan Region between June 2004 and August 2006. These samples were stored at -70 ° C, and 200 of them were randomly chosen and analyzed to determine VVZ IgG (ELISA). RESULTS: 179 samples from 179 children, 65% male. Ninety eighth/179 (55%) were positive, 72/179 (40%) negative and 9/179 (5%) indeterminate. Stratified by age, seropositive percentage was: 1 to 4 years 32%, 5-9 years 42%, 10-14 years 78%, over 15 years 88%. CONCLUSION: Forty percent of children treated for cancer are seronegative to VVZ infection, a frequency that decreases with age. These results support the adoption of preventive measures to avoid infection in this population of children at risk of developing a serious and possibly fatal illness.


Asunto(s)
Varicela/epidemiología , Herpesvirus Humano 3/inmunología , Huésped Inmunocomprometido/inmunología , Neoplasias/inmunología , Adolescente , Anticuerpos Antivirales/sangre , Varicela/diagnóstico , Varicela/inmunología , Niño , Preescolar , Chile/epidemiología , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Lactante , Masculino , Prevalencia , Estudios Seroepidemiológicos
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