Factores de riesgo de bacteriemia en niños con cáncer y neutropenia febril / Risk factors for bacteremia in children with cancer and febrile neutropenia

La bacteriemia representa una importante causa de morbimortalidad en pacientes oncológicos. Durante el episodio de neutropenia inducida por quimioterapia, un 15%­25% de los pacientes tendrá bacteriemia. Objetivo: identificar factores de riesgo asociados con bacteriemia en pacientes oncológicos pediátricos con neutropenia y fiebre. Material y métodos: estudio de cohorte prospectivo. Se incluyeron pacientes con enfermedades hematooncológicas y neutropenia febril, internados en un hospital pediátrico de alta complejidad entre julio de 2018 y mayo de 2019. Se excluyeron receptores de trasplante de médula ósea. Se compararon las características clínicas según se documentara bacteriemia (B) o no. Resultados: Se incluyeron 160 pacientes (p). Eran varones 93 (58%). La mediana de edad fue 81,5 meses (RIC 36-127,5). La enfermedad de base (EB) más frecuente fue: leucemia linfoblástica aguda (LLA) 88 (55%). Se identificaron 20 (12,5%) pacientes con bacteriemia (B). En el análisis univariado hubo asociación entre B y LMA (p=0,003) y la internación en UCI (p=0,0001). En el modelo multivariado, ajustado por el resto de las variables, se identificaron la LMA (OR 8,24, IC95% 2,5-26,4; p<0,001) y la tiflitis (OR 5,86, IC95% 1,2-27,3; p=0,02) como factores relacionados con bacteriemia. Los principales microorganismos identificados fueron: estreptococos del grupo viridans 6 (30%), Escherichia coli 4 (20%) y estafilococos coagulasa negativos 3 (15%). Quince (75%) fueron bacteriemias secundarias a un foco clínico. El foco más frecuente fue el mucocutáneo (n=7, 35%). En esta cohorte de niños con cáncer y neutropenia febril, los factores asociados con bacteriemia fueron: la LMA, la tiflitis y la internación en UCI (AU)

Bacteremia is an important cause of morbidity and mortality in oncology patients. During an episode of chemotherapy-induced neutropenia, 15%-25% of patients will develop bacteremia. Objective: to identify risk factors associated with bacteremia in pediatric oncology patients with neutropenia and fever. Material and methods: prospective cohort study. Patients with hematology-oncology diseases and febrile neutropenia, admitted to a tertiary-care pediatric hospital between July 2018 and May 2019 were included. Bone marrow transplant recipients were excluded. Clinical characteristics were compared according to whether or not bacteremia was recorded. Results: 160 patients were included of whom 93 (58%) were male. Median age was 81.5 months (IQR 36-127.5). The most common underlying disease was acute lymphoblastic leukemia (ALL) in 88 patients (55%). Twenty (12.5%) patients with bacteremia were identified. In univariate analysis, an association was found between bacteremia and acute myeloid leukemia (AML) (p=0.003) and ICU admission (p=0.0001). In the multivariate model, adjusted for the remaining variables, AML (OR 8.24; 95%CI 2.5-26.4; p<0.001) and typhlitis (OR 5.86; 95%CI 1.2-27.3; p=0.02) were identified as factors related to bacteremia. The main microorganisms identified were viridans group streptococci in 6 (30%), Escherichia coli in 4 (20%), and coagulase negative staphylococci in 3 (15%). In 15 cases (75%), bacteremia was secondary to a clinical focus. The most frequent focus was mucocutaneous (n=7, 35%). In this cohort of children with cancer and febrile neutropenia, the factors associated with bacteremia were AML, typhlitis, and ICU admission (AU)

Adsorption kinetics and Box-Behnken design optimization for organic dyes on tungsten oxide.

Transition metal oxides have been applied to degrade organic dyes found in water bodies via photocatalysis. To do it, however, is essential that the dye molecules adsorb onto the metal oxide surface. Thus, optimizing the adsorption capacity of the adsorbent increases the probability of reaction between oxidation radicals and organic dye molecules and maximizes the effectiveness per gram of photocatalyst. With this in mind, we studied the adsorption behavior of Methylene Blue (MB) and Acid Orange 7 (AO7), two commonly found pollutants, as a function of dilution's pH, WO3 load, and initial dye concentration. We found out that WO3 adsorbs up to 80% of MB at pH = 6, and 13% of AO7 at pH = 2, although it is unable to adsorb AO7 at the natural pH of the dye dilution. Assuming a pseudo-second order kinetics model for the analysis of the MB adsorption amount, we determined a rate constant k2 = 6 × 10-2(g · mg-1)/min for the adsorption process. We put forward a molecular model for adsorption, driven by concentration gradients and electrostatic interactions. Finally, from a statistical analysis, we determined that pH is the most significant factor for the adsorption of MB and AO7 on WO3, reinforcing the notion that electrostatic interactions are the main mechanism driving the adsorption process. The Box-Behnken design optimization also evinces the key playing role of WO3 load in the adsorption percentage of AO7 and let us establish the optimal load required to maximize adsorption.

[Prevalence of injury of the medial collateral ligament of the knee assessed by magnetic resonance]. / Prevalencia de lesión del ligamento colateral medial de la rodilla valorada por resonancia magnética.

INTRODUCTION: The medial collateral ligament (MCL) is one of the main stabilizers of the knee, but its injury occurs in conjunction with other ligaments. OBJECTIVE: To determine the prevalence of MCL lesions by magnetic resonance imaging, their degrees and associated lesions in our institution. MATERIAL AND METHODS: Retrospective study from January to April 2018 where KNEE MRIs were evaluated where the MCL lesion was presented to evaluate the degree and type of associated injuries. RESULTS: We included 368 studies, prevalence of isolated MCL lesion of 3.07%, grade I and grade II, prevalence of concomitant MCL lesions was 17.66% grade I (75%), grade II (15%) and grade III (3%). Associated injuries were medial meniscus injury (46.15%), anterior cruciate ligament injury (30.7%), isolated bone contusion (18.46%), chodral injuries (37.58%), medial vastus injury (14.51%), patellar medial retinacular injury (14.51%), vastus lateral injury (9.23%), posterior cruciate ligament injury (6.15%), lateral meniscus injury (4.61%), iliotibial band tenosynovitis (4.61%), medial facet avulsion fracture (3.07%), Pes Anserine tenosynovitis (3.07%). CONCLUSION: Prevalence of 17.66% of the MCL injuries in our hospital by magnetic resonance, the first 2 degrees predominate, with a wide spectrum of associated knee injuries.

INTRODUCCIÓN: El ligamento colateral medial (LCM) es uno de los principales estabilizadores de la rodilla, pero su lesión se presenta en conjunto con otras lesiones ligamentarias. OBJETIVO: Determinar la prevalencia de lesiones del LCM por resonancia magnética, sus grados y lesiones asociadas en nuestra institución. MATERIAL Y MÉTODOS: Estudio retrospectivo de Enero a Abril de 2018, se evaluaron resonancias magnéticas de rodilla donde se presentó lesión del LCM para evaluar grado y tipo de lesiones asociadas. RESULTADOS: Se incluyeron 368 estudios, prevalencia de lesión aislada del LCM de 3.07%, una grado I y una grado II, la prevalencia de lesiones de LCM concomitantes fue de 17.66%, grado I (75%), grado II (15%) y grado III (3%). Las lesiones asociadas fueron lesión del menisco medial (46.15%), lesión del ligamento cruzado anterior (30.7%), contusión ósea aislada (18.46%), lesiones condrales (37.58%), lesión de vasto medial (14.51%), lesión del retináculo medial patelar (14.51%), lesión del vasto lateral (9.23%), lesión del ligamento cruzado posterior (6.15%), lesión del menisco lateral (4.61%), tenosinovitis banda iliotibial (4.61%), fractura de avulsión de la faceta medial (3.07%), tenosinovitis de la Pes Anserinus (3.07%). CONCLUSIÓN: Prevalencia de 17.66% de lesiones del LCM en nuestro hospital por resonancia magnética, predominan los dos primeros grados con un espectro amplio de lesiones asociadas de la rodilla.

Características clínicas y evolutivas de niños con infección por SARS-CoV-2 en un hospital de alta complejidad: estudio de cohorte / Clinical and outcome characteristics of children with SARS CoV-2 infection in a tertiary-care hospital: a cohort study

Introducción: Las infecciones por SARS-CoV-2 representan un problema de salud pública a nivel mundial. En los niños se reporta menor incidencia y cuadros clínicos más leves. Se realizó el presente estudio con el objetivo de describir las características clínicas y evolutivas de los niños con diagnóstico de infección por SARS CoV-2 en el Hospital Juan P. Garrahan. Material y métodos: estudio de cohorte prospectivo. Se incluyeron todos los pacientes con diagnóstico confirmado por PCR de COVID-19 desde 20.4.20 hasta el 3.07.21 y con seguimiento en el hospital de Pediatría Juan P. Garrahan. Resultados: n: 1644. Eran varones 836 (51%). La mediana de edad fue 75 meses (RIC 22- 143). Tenían alguna enfermedad de base previa al diagnóstico de COVID-19: 884 pacientes (53,7%), la más frecuente fue la enfermedad oncohematológica. Estaban asintomáticos 423 pacientes (25,7%). De los pacientes sintomáticos, 1071 (65,1%) presentaron cuadro leve, 5 (0,3%) moderado, 69 (4,2%) grave y 76 (4,6%) crítico. La fiebre fue el hallazgo más frecuente n: 782; (47,5%). Se internaron 900 pacientes (54,7%), 33 en UCI (2%). Fallecieron 7 pacientes (0,4%), todos ellos con comorbilidades graves. Conclusiones: En este estudio de cohorte de niños con infección por SARS-CoV-2 confirmada, predominaron los pacientes con enfermedad de base y las formas leves de COVID-19. El ingreso a UCI fue menor al 2%. Fallecieron 7 pacientes (0.4%) todos ellos con comorbilidades y coinfecciones (AU)

Introduction: SARS-CoV-2 infections represent a worldwide public health problem. A lower incidence and milder clinical pictures are reported in children. The aim of this study was to describe clinical and outcome characteristics of children diagnosed with SARS-CoV-2 infection at Hospital de Pediatría Juan P. Garrahan. Methods: A prospective cohort study was conducted. All patients with a PCR-confirmed diagnosis of COVID-19 seen between 20.4.20 and 3.07.21 and followed-up at Hospital de Pediatría Juan P. Garrahan were included. Results: n: 1644; 836 males (51%) were male. Median age was 75 months (IQR, 22-143). Overall, 884 patients (53.7%) had an underlying disease prior to COVID-19 diagnosis, most frequently hematologic/ oncologic disease. 423 patients (25.7%) were asymptomatic. Of the symptomatic patients, 1071 (65.1%) had mild, 5 (0.3%) moderate, 69 (4.2%) severe, and 76 (4.6%) critical disease. Fever was the most frequent finding (n: 782; 47.5%). A total of 900 patients (54.7%) were admitted, 33 of whom to the ICU (2%). Seven patients (0.4%) died, all with severe comorbidities. Conclusions: In this cohort study of children with confirmed SARSCoV-2 infection, patients with underlying disease and mild forms of COVID-19 predominated. ICU admission occurred in less than 2%. Seven patients (0.4%) died, all of them with comorbidities and coinfections. (AU)

Epidemiología de COVID-19 / Epidemiology of COVID-19

El 31 de diciembre de 2019, en el estado de Wuhan, al sur de China, se notificaron los primeros casos de una enfermedad nueva que se denominó COVID-19. Se identificó al virus SARS-CoV-2 como el agente etiológico. Esta enfermedad fue declarada pandemia por la OMS en marzo 2020. El objetivo de este trabajo es describir la epidemiología de la COVID-19 y las características particulares de los niños con esta enfermedad. El SARS-CoV-2 es un virus ARN que pertenece a la familia Coronaviridae. Su trasmisión es principalmente interhumana a través de pequeñas gotitas respiratorias y también mediante aerosoles. En la clínica puede presentarse de forma asintomática o con un cuadro grave de distrés respiratorio. Puede haber manifestaciones cutáneas, gastrointestinales y/o cardiovasculares entre otras. En los niños se describió un síndrome inflamatorio denominado síndrome inflamatorio multisistémico asociado a SARS-CoV-2 (SIMS). La evidencia sobre el rol de los niños en la transmisión de la enfermedad es creciente. En la Argentina, desde el inicio de la pandemia hasta junio 2021, se notificaron más de 4 000 000 de casos confirmados de COVID-19 y, 90 000 personas fallecidas. Las infecciones por SARS-CoV-2 representan un desafío sanitario global. El rol de los niños como dispersores de la enfermedad y su real carga de enfermedad continúan en estudio (AU)

On December 31, 2019, in the state of Wuhan, southern China, the first cases of a new disease named COVID-19 were reported. The SARS-CoV-2 virus was identified as the etiologic agent. This disease was declared a pandemic by the WHO in March 2020. The aim of this study was to describe the epidemiology of COVID-19 and the particular characteristics of children with this disease. SARS-CoV-2 is an RNA virus belonging to the Coronaviridae family. Its transmission is mainly human-to-human through small respiratory droplets and aerosols. Clinically, it may present asymptomatically or with severe respiratory distress. There may be cutaneous, gastrointestinal and/or cardiovascular manifestations, among others. In children, SARS-CoV-2-associated multisystemic inflammatory syndrome (MIS) has been described. There is growing evidence on the role of children in the transmission of COVID-19. In Argentina, from the onset of the pandemic until June 2021, more than 4 000 000 confirmed cases of COVID-19 and 90 000 deaths have been reported. SARSCoV-2 infections represent a global health challenge. Research on the role of children as disease spreaders and their actual disease burden is ongoing (AU)

Epidemiología de las meningitis bacterianas en niños en un hospital pediátrico: 2011-2016 / Epidemiology of bacterial meningitis in children at a pediatric hospital: 2011-2016

Introducción: Las meningitis bacterianas en niños son causa de importante morbimortalidad. Los principales agentes etiológicos son Neisseria meningitidis, Streptococcus pneumoniae y Haemophilus influenzae. En los últimos años, luego de la introducción sucesiva de vacunas conjugadas al calendario nacional de inmunizaciones, se ha visto un cambio en la epidemiología de estas infecciones. Objetivo: Describir las características clínicas, epidemiológicas y evolutivas de los niños hospitalizados con meningitis bacteriana confirmada microbiológicamente entre 2011 y 2016 en un hospital de tercer nivel de complejidad. Materiales y métodos: Cohorte retrospectiva. Se incluyeron niños entre 1 mes de vida y 17 años con cuadro clínico compatible con meningitis bacteriana y cultivo positivo y/o PCR en líquido cefalorraquídeo y/o hemocultivos positivos para Neisseria meningitidis, Streptococcus pneumoniae y Haemophilus influenzae b. Se registraron las características demográficas, clínicas y evolutivas hasta los 30 días del egreso. Se utilizó mediana y rango intercuartilo (RIC) para variables continuas y porcentaje para variables categóricas. Se utilizó Stata 10. Resultados: n=65. Edad: mediana de 9 meses (RIC 4-35). Varones: 58% (n=38). Se identificó Neisseria meningitidis en un 48% (n=31), Haemophilus influenzae b en un 26% (n=17) y Streptococcus pneumoniae en un 26% (n=17). El 26% (n=17) de los pacientes presentaba alguna comorbilidad. Tuvieron hemocultivos positivos el 62% (n = 40) de los pacientes y 86% (n=55) de los líquidos cefalorraquídeos. Todos los pacientes recibieron tratamiento antimicrobiano con ceftriaxona tanto como tratamiento empírico como definitivo y 92% (n=60) recibieron corticoides empíricos. La mediana de días de internación fue de 11 (RIC 8-17). El 28% (n=18) requirió cuidados intensivos, y el 8% (n=5) falleció. Durante el período de estudio se observó que la frecuencia de meningitis por Streptococcus pneumoniae disminuyó en el final del estudio (9% en 2016 vs 60% en 2011), mientras que la frecuencia de meningitis por Neisseria meningitidis en 2016 fue mayor que al inicio del período (64% en 2016 vs. 40% en 2011). La frecuencia de identificación de Haemophilus influenzae b se mantuvo estable. Conclusiones: Las meningitis bacterianas confirmadas por Neisseria meningitidis, Streptococcus pneumoniae y Haemophilus influenzae b prevalecieron en niños menores de 12 meses. En esta cohorte se observó un predominio de las infecciones por Neisseria meningitidis en los últimos años, y una disminución en la frecuencia de meningitis por Streptococcus pneumoniae en el período post introducción de la vacuna conjugada 13 valente al calendario nacional de inmunizaciones. (AU)

Introduction: In children, bacterial meningitis is an important cause of morbidity and mortality. The main etiological agents are Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae. Over the last years, the successive introduction of conjugated vaccines in the national immunization calendar has led to a change in the epidemiology of these infections. Objective: To describe the clinical and epidemiological features and outcome of children admitted because of microbiologically confirmed meningitis seen between 2011 and 2016 at a tertiary care hospital. Material and methods: A retrospective cohort study was conducted. Children between 1 month of life and 17 years of age with clinical features compatible with bacterial meningitis and positive cultures and/or PCR in cerebrospinal fluid (CSF) and/or positive blood cultures for Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae b were included. Demographic, clinical, and outcome features were recorded until 30 days after discharge. Median and interquartile range (IQR) were calculated for continuous variables and percentages for categorical variables. The Stata 10 program was used. Results: n=65. Age: median was 9 months (IQR 4-35). Boys: 58% (n=38). Neisseria meningitidis was identified in 48% (n=31), Haemophilus influenzae b in 26% (n=17), and Streptococcus pneumoniae in 26% (n=17). Overall, 26% (n=17) of the patients presented with comorbidities. Positive blood cultures were found in 62% (n = 40) and positive CSF cultures in 86% (n=55) of the patients. All patients received antimicrobial treatment with ceftriaxone both empirically and as final treatment and corticosteroids were empirically started in 92% (n=60). Median hospital stay was 11 days (IQR 8-17). Overall, 28% (n=18) required intensive care and 8% (n=5) of the patients died. The incidence of meningitis due to Streptococcus pneumoniae was observed to diminish at the end of the study period (9% in 2016 vs 60% in 2011), while the incidence of meningitis due to Neisseria meningitidis in 2016 was higher than at the end of the study period (64% in 2016 vs. 40% in 2011). The frequency of identification of Haemophilus influenzae b remained stable. Conclusions: Confirmed bacterial infections due to Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae b were prevalent in infants younger than 12 months of age in this cohort of patients. Infections due to Neisseria meningitidis predominated over the last years and the incidence of meningitis due to Streptococcus pneumoniae diminished after the introduction of the 13 valent conjugated vaccine was introduced in the national immunization calendar.(AU)

Statistical comparison of the slopes of two regression lines: A tutorial.

Comparing the slopes of two regression lines is an almost daily task in analytical laboratories. The usual procedure is based on a Student's t-test although literature differs in whether the standard errors of the slopes or the standard errors of the regressions should be employed to get a pooled standard error. In this work fundamental concepts on the use of the Student's test were reviewed and Monte Carlo simulations were done to ascertain whether relevant differences arise when the two options are considered. It was concluded that for small sample sets (as it is usual in analytical laboratories) the Student's t-test based on the standard error of regression models must be used and special attention must be paid on the equality of the models variances. Finally, alternative approaches were reviewed, with emphasis on a simple one based on the analysis of the covariance (ANCOVA).