Cumulative incidence, prevalence, seroconversion, and associated factors for SARS-CoV-2 infection among healthcare workers of a University Hospital in Bogotá, Colombia.

This study aimed to determine the cumulative incidence, prevalence, and seroconversion of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its associated factors among healthcare workers (HCWs) of a University Hospital in Bogotá, Colombia. An ambispective cohort was established from March 2020 to February 2021. From November 2020 to February 2021, SARS-CoV-2 antibodies were measured on two occasions 14-90 days apart to determine seroprevalence and seroconversion. We used multivariate log-binomial regression to evaluate factors associated with SARS-CoV-2 infection. Among 2,597 HCWs, the cumulative incidence of infection was 35.7%, and seroprevalence was 21.5%. A reduced risk of infection was observed among those aged 35-44 and ≥45 years (adjusted relative risks [aRRs], 0.84 and 0.83, respectively), physicians (aRR, 0.77), those wearing N95 respirators (aRR, 0.82) and working remotely (aRR, 0.74). Being overweight (aRR, 1.18) or obese (aRR, 1.24); being a nurse or nurse assistant (aRR, 1.20); working in the emergency room (aRR, 1.45), general wards (aRR, 1.45), intensive care unit (aRR, 1.34), or COVID-19 areas (aRR, 1.17); and close contact with COVID-19 cases (aRR, 1.47) increased the risk of infection. The incidence of SARS-CoV-2 infection found in this study reflects the dynamics of the first year of the pandemic in Bogotá. A high burden of infection calls for strengthening prevention and screening measures for HCWs, focusing especially on those at high risk.

Seroprevalence and seroconversion rates to SARS-CoV-2 in interns, residents, and medical doctors in a University Hospital in Bogotá, Colombia / Tasas de seroprevalencia y seroconversión al SARS-CoV-2 en internos, residentes y médicos en un Hospital Universitario de Bogotá, Colombia

Abstract Objectives: To determine the prevalence of antibodies to SARS-CoV-2 and the incidence of seroconversion in the first month of follow-up among interns, residents, and medical doctors attending patients at a University Hospital in Bogota (Colombia). Design or methods: A cross-sectional and a prospective study were performed during June, July, and August 2020 to assess seroprevalence and seroconversion rates using CLIA IgG for SARS-CoV-2. LFA IgG and IgM and ELFA IgM were also determined to explore concordance with CLIA IgG. Results: At baseline, 8 (2.28% 95%CI 1.16-4.43%) participants were IgG positive for SARS-CoV-2 by CLIA. At the end of the study, 21 (5.98% 95%CI 3.94-8.97%) individuals seroconverted by CLIA IgG. In all, 29 individuals had IgG by CLIA and of these 11 (3.13% 95%CI 1.76-5.52%) were asymptomatic. No associations with risk factors for infection were identified. CLIA IgG had moderate concordance (>962 samples) with LFA IgG and ELFA IgM, but minimal with LFA IgM. Conclusions: Our report is the first in Latina America on seroprevalence and seroconversion rates in medical healthcare workers. The relatively high rate (>3%) of asymptomatic health care workers with evidence of previous SARS-CoV-2 infection underscores the need to screen this population for infection to prevent infection/disease spread.

Resumen Objetivos: Determinar la prevalencia de anticuerpos frente al SARS-CoV-2 y la incidencia de seroconversión en el primer mes de seguimiento en internos, residentes y médicos que atienden pacientes en un Hospital Universitario de Bogotá (Colombia). Diseño y métodos: Se realizó un estudio transversal y prospectivo durante junio, julio y agosto de 2020 para evaluar las tasas de seroprevalencia y seroconversión utilizando CLIA IgG para SARS-CoV-2. También se determinaron LFA IgG e IgM y ELFA IgM para explorar la concordancia con CLIA IgG. Resultados: Al inicio del estudio, 8 (2,28% IC del 95% 1,16-4,43%) participantes fueron IgG positivos para SARS-CoV-2 por CLIA. Al final del estudio, 21 (5,98% IC 95% 3,94-8,97%) individuos seroconvirtieron por CLIA IgG. En total, 29 individuos tenían IgG por CLIA y de estos 11 (3,13% 95% IC 1,76-5,52%) eran asintomáticos. No se identificaron asociaciones con factores de riesgo de infección. El CLIA IgG tuvo una concordancia moderada (> 962 muestras) con LFA IgG y ELFA IgM, pero mínima con el LFA IgM. Conclusiones: Nuestro informe es el primero en América Latina sobre tasas de seroprevalencia y seroconversión en trabajadores médicos de la salud. La tasa relativamente alta (> 3%) de trabajadores de la salud asintomáticos con evidencia de infección previa por SARS-CoV-2 resalta la necesidad de realizar pruebas de detección de infección en esta población para prevenir la propagación de la infección.

Risk Factors And Prevention of Peritoneal Dialysis-Related Peritonitis.

BACKGROUND: Peritonitis is a major complication and the main cause of peritoneal dialysis (PD) failure. The aim of the present study was to evaluate peritonitis risk factors and its prevention with a new peritoneal educational program (NPEP). METHODS: We performed a retrospective analysis of a cohort of chronic PD patients, older than 16 years, who began PD in the period 1 January 1999 to 31 December 2015 at a Uruguayan PD center, with follow-up until 31 December 2016. RESULTS: The population included 222 cases (219 patients, 128 men), median age 59 (interquartile range [IQR] 47.0 - 72.0) years, median time on PD 17.5 (IQR 6.0 - 36.2) months. Ninety-five patients suffered 1 or more episodes of peritonitis, and they had been on PD for a longer period and had nasal-positive culture more frequently. A NPEP started in September 2008; patients who trained with it, as well as younger patients, had longer peritonitis-free survival. After the NPEP, global peritonitis rates decreased significantly (from 0.48 to 0.29 episodes/patient-year, respectively), particularly gram-positive bacteria and Staphylococcus aureus / coagulase-negative (CoNS) (from 0.26 to 0.12 and 0.21 to 0.07 episodes/patient-year, respectively). In the multivariate Cox analysis of peritonitis risk factors, survival to first peritonitis was significantly associated only with age (hazard ratio [HR] 1.024, 95% confidence interval [CI] 1.007 - 1.397, p = 0.007) and the NPEP (HR 0.600, 95% CI 0.394 - 0.913, p = 0.017). CONCLUSION: A multidisciplinary peritoneal educational program may improve peritonitis rates, independently of other risk factors.

Enterobacterias productoras de b-lactamasas de espectro-extendido y plásmido-ampc en aguas de riego, zona maica, cochabamba / Extended-spectrum b-lactamase and plasmid ampc b-lactamase-producing enterobacteriaceae in water sources for irrigation in maica's zone, cochabamba

Introducción: Las enterobacterias han ido adquiriendo mecanismos de resistencia a los antimicrobianos, como la producción de Beta Lactamasas de Espectro Extendido (BLEE) que otorga resistencia a varios beta-lactámicos. Estas bacterias, capaces de causar infecciones intrahospitalarias y comunitarias difíciles de tratar, se están diseminando y habitan reservorios ambientales, como aguas;y es considerado un problema de salud pública. Situación desconocida en nuestro medio. Objetivo: Identificar Enterobacterias productoras de BLEE y AmpC en agua de los ríos Tamborada y Rocha, utilizados para el riego de cultivos en la zona Maica de Cochabamba. Métodos: Estudio descriptivo, transversal y cuantitativo. Se analizaron 70 muestras de agua: 44 del rio Tamborada y 26 del Rocha. Las muestras se cultivaron en Agar MacConkey con Cefotaxima (2 μm/ml). Las bacterias que crecieron se identificaron con agar cromogénico y pruebas bioquímicas. Las cepas productoras de BLEE y tipo AmpC se determinaron por difusión y aproximación de discos: Cefotaxima, ceftazidima, Amoxicilina/Acido clavulánico para BLEE y Cefoxitin para AmpC. Resultados: Se aislaron 23 cepas de Escherichia coli (E. coli) productoras de BLEE (32,8%) de las 70 muestras y 22 muestras (resistentes a cefoxitin) que podrían tener además resistencia tipo AmpC. Conclusión: E. coli productoras de BLEE y probablemente AmpC están circulando en ambientes de nuestro medio como ser agua de Ríos Tamborada y Rocha, esto representa un problema de salud pública, más si consideramos que estas aguas son utilizadas en riego de verduras que abastecen los mercados de Cochabamba y pueden diseminar estas bacterias entre la población.

Introduction: Enterobacteria have been acquiring antimicrobial resistance mechanisms, such as the production of extended spectrum beta lactamases (ESBL) thatgives resistance to several beta-lactams.These bacteria, capable of causing intrahospital and community infections difficult to treat, are spreading and inhabit environmental reservoirs, such as water; and is considered a public health problem. Unknown situation in our environment. Objective: Identify Enterobacteria producing BLEE and AmpC in water from the Tamborada and Rocha rivers, used for irrigation of crops in the Maica area of Cochabamba. Methods: Descriptive, cross-sectional and quantitative study. 70 water samples were analyzed: 44 from the Tamborada river and 26 from Rocha.The samples were grown in MacConkey Agar with Cefotaxime (2 μm/ml). Bacteria that grew were identified with chromogenic agar and biochemical tests.The ESBL and AmpC type producing strains were determined by diffusion and approximation of discs: Cefotaxime, Ceftazidime, Amoxicillin/Clavulanic acid for ESBL; and Cefoxitin for AmpC. Results: 23 strains of ESBL-producing Escherichia coli (32.8%) were isolated from the 70 samples. 22 of these isolates (resistant to cefoxitin) could also have AmpC resistance. Conclusion: E. coli producers of ESBL and probably AmpC are circulating in our environment such as waters of Rocha and Tamborada rivers, which represent a public health problem, more if we consider that these waters are used in irrigation of vegetables that they supply Cochabamba markets and can spread these bacteria among the population.

Study of body fluid samples using flow cytometry: Six years of experience at the Hospital Universitario San Ignacio - Pontificia Universidad Javeriana, Bogota - Colombia / Estudio de muestras de fluidos corporales utilizando citometría de flujo: seis años de experiencia en el Hospital Universitario San Ignacio - Pontificia Universidad Javeriana Bogotá, Colombia / Estudo de amostras de fluídos corporais utilizando citometria de fluxo: seis anos de experiencia no Hospital Universitário San Ignacio - Pontificia Universidad Javeriana, Bogotá, Colômbia

Abstract Flow cytometry (FCM) was implemented in 2008 at the Pontificia Universidad Javeriana and later at the Hospital Universitario San Ignacio to examine special samples of patients with hematological malignancies and solid tumors other than bone marrow and peripheral blood for diagnosis and monitoring. This study describes the main findings of special sample evaluation over a six-year period. In all, 1070 samples of body fluids from patients with benign and malignant diseases were examined by FCM. These samples were stabilized with TransFixTM and stained with six-color immunophenotyping panels. Samples included cerebrospinal fluid, bronchoalveolar lavage, pleural fluid, pericardial fluid and ascite fluid from patients with acute and chronic leukemia, myelodysplastic syndromes, lymphomas, myeloma, autoimmune diseases, immunodeficiencies and solid tumors, among others. Flow cytometry provided important information for the classification and detection of minimal numbers of tumor cells in leukemia and lymphoma cases. This work represents the first national report describing FCM implementation in special samples for diagnosis and clinical monitoring of patients with malignant and benign pathologies.

Resumen La citometría de flujo fue implementada en 2008 en la Pontificia Universidad Javeriana y posteriormente en el Hospital San Ignacio con el fin de examinar, para diagnóstico y monitoreo, muestras especiales de pacientes con malignidades hematológicas y tumores sólidos, distintos de los de médula ósea y sangre periférica. Este estudio describe los principales hallazgos de la evaluación de estas muestras especiales en un periodo de seis años. En total, se examinaron por citometría de flujo 1070 muestras de fluidos corporales de pacientes con enfermedades malignas y benignas. Estas muestras se estabilizaron con TransFix™ y teñidas con paneles inmunofenotípicos de seis colores. Las muestras incluyeron líquido cefalorraquídeo, lavado broncoalveolar, fluido pleural, fluido pericárdico y fluido ascítico, provenientes de pacientes con leucemia aguda y crónica, síndromes mielodisplásicos, linfomas, mieloma, enfermedades autoinmunes, inmunodeficiencias y tumores sólidos, entre otras enfermedades. La citometría de flujo proporcionó información importante sobre la clasificación y detección de números mínimos de células tumorales en casos de leucemia y linfoma. Este trabajo representa el primer reporte nacional que describe la implementación de citometría de flujo en muestras especiales para diagnóstico y monitoreo clínico de pacientes con patologías malignas y benignas.

Resumo A citometria de fluxo foi implementada em 2008 na Pontificia Universidad Javeriana e posteriormente no Hospital San Ignacio com a finalidade de examinar amostras especiais de pacientes com malignidades hematológicas e tumores sólidos diferentes aos de medula óssea e sangue periférico para diagnóstico e monitoramento. Este estudo descreve as principais descobertas a partir da avaliação de amostras especiais em um período de 6 anos. Se examinaram por citometria de fluxo um total de 1.070 amostras de fluídos corporais de pacientes doenças malignas e benignas. Estas amostras se estabilizaram com TransFix™ e coradas com painéis imunofenotípicos de seis cores. As amostras incluíram fluído cérebro-espinhal, lavado broncoalveolar, fluído pleural, fluído pericárdico e fluído ascético, provenientes de pacientes com leucemias aguda e crónica, síndromes mielodisplásicos, linfomas, mielomas, doenças autoimunes, imunodeficiência, e tumores sólidos, entre outras doenças. A citometria de fluxo proporcionou informações importantes sobre a classificação e detecção de um número mínimo de células tumorais nos casos de leucemia e linfomas. Este trabalho representa o primeiro relato nacional que descreve a implementação de citometria de fluxo em amostras especiais para diagnóstico e monitoramento clínico de pacientes com patologias malignas e benignas.

Valores séricos de ácido fólico en un grupo de pacientes mayores de 18 años de edad en un hospital de alta complejidad / Serum Folic Acid Values in a Group of Patients over 18 Years of Age in a Highly Complex Hospital

Objetivo: establecer las concentraciones séricas de ácido fólico en un grupo de pacientes adultos. Métodos: medición del ácido fólico con inmunoanálisis en 1797 sujetos. Se calcularon medidas de tendencia central e índice de confianza al 95 %. Se compararon grupos etarios y sexos con pruebas no paramétricas. Resultados: la media global de ácido fólico sérico fue: 11,61 ng'ml (DE: 6,05). La media en mujeres fue de 11,87 ng'ml (DE: 6,09). La media en hombres fue de 11,31 ng'ml (DE: 6). Se reportaron los percentiles 5, 50 y 95 por sexo y edad. En el 2 % de los casos se encontró ácido fólico < 2 ng'ml (2 % de hombres y 3 % de mujeres). Discusión: las concentraciones séricas de ácido fólico son mayores en mujeres que en hombres (p = 0,024), lo que contrasta con la noción de déficit del micronutriente en el sexo femenino. Conclusiones: las cantidades descritas son un comparador adecuado para mediciones en muestras de población general.

Objective: lo establish the serum levels of folie acid in a group of adult patients. Methods: Measurement of folie acid using ¿mmunoassay in 1797 subjeets. Níeasures of central tendeney and 95% CI were calculated. Age groups and genders were compared with non-parametric tests. Results: The overall mean serum folate was: 11.61 ng'ml (SD: 6.05). The average for women was: 11.87 ng'ml (SD: 6.09). The average for men was: 11.31 ngml (SD: 6). Percentiles 5, 50, and 95 by sex and age are reported. In 2% of cases folie acid was found < 2 ng'ml (2% of men and 3% women). Discussion: Serum levels of folie acid are higher in women than in men (p=0.024), which contrasts with the notion of micronutrient defíciency in remides. Condusions: The presented measurements are an appropriate comparator described for measurements in general population samples.

High expression of ID family and IGJ genes signature as predictor of low induction treatment response and worst survival in adult Hispanic patients with B-acute lymphoblastic leukemia.

BACKGROUND: B-Acute lymphoblastic leukemia (B-ALL) represents a hematologic malignancy with poor clinical outcome and low survival rates in adult patients. Remission rates in Hispanic population are almost 30% lower and Overall Survival (OS) nearly two years inferior than those reported in other ethnic groups. Only 61% of Colombian adult patients with ALL achieve complete remission (CR), median overall survival is 11.3 months and event-free survival (EFS) is 7.34 months. Identification of prognostic factors is crucial for the application of proper treatment strategies and subsequently for successful outcome. Our goal was to identify a gene expression signature that might correlate with response to therapy and evaluate the utility of these as prognostic tool in hispanic patients. METHODS: We included 43 adult patients newly diagnosed with B-ALL. We used microarray analysis in order to identify genes that distinguish poor from good response to treatment using differential gene expression analysis. The expression profile was validated by real-time PCR (RT-PCT). RESULTS: We identified 442 differentially expressed genes between responders and non-responders to induction treatment. Hierarchical analysis according to the expression of a 7-gene signature revealed 2 subsets of patients that differed in their clinical characteristics and outcome. CONCLUSIONS: Our study suggests that response to induction treatment and clinical outcome of Hispanic patients can be predicted from the onset of the disease and that gene expression profiles can be used to stratify patient risk adequately and accurately. The present study represents the first that shows the gene expression profiling of B-ALL Colombian adults and its relevance for stratification in the early course of disease.

Platelets promote mitochondrial uncoupling and resistance to apoptosis in leukemia cells: a novel paradigm for the bone marrow microenvironment.

Here we report that leukemia cell lines and primary CD34+ leukemic blasts exposed to platelet rich plasma (PRP) or platelet lysates (PL) display increased resistance to apoptosis induced by mitochondria-targeted agents ABT-737 and CDDO-Me. Intriguingly, leukemia cells exposed to platelet components demonstrate a reduction in mitochondrial membrane potential (ΔΨM) and a transient increase in oxygen consumption, suggestive of mitochondrial uncoupling. Accompanying the ranolazine-sensitive increase in oxygen consumption, a reduction in triglyceride content was also observed in leukemia cells cultured with platelet components indicating that lipolysis and fatty acid oxidation may support the molecular reduction of oxygen in these cells. Mechanistically, platelet components antagonized Bax oligomerization in accordance with previous observations supporting an antiapoptotic role for fatty acid oxidation in leukemia cells. Lastly, substantiating the notion that mitochondrial uncoupling reduces oxidative stress, platelet components induced a marked decrease in basal and rotenone-induced superoxide levels in leukemia cells. Taken together, the decrease in ΔΨM, the transient increase in ranolazine-sensitive oxygen consumption, the reduction in triglyceride levels, and the reduced generation of superoxide, all accompanying the increased resistance to mitochondrial apoptosis, substantiate the hypothesis that platelets may contribute to the chemoprotective sanctuary of the bone marrow microenvironment via promotion of mitochondrial uncoupling.

Determinacion de valores de linfocitos TCD3+, CD3+/CD4+ y CD3+/CD8+ por citometria de flujo en adultos donantes de sangre del Hospital Universitario San Ignacio de Bogota / Determination of values of T-lymphocytes TCD3+, CD3+/CD4+ and CD3+/CD8+ for flow cytometry in donors blood adults of in Hospital Universitario San Ignacio, Bogota

Objetivo: determinar los valores de linfocitos T CD3+, CD3+/CD4+ y CD3+/CD8+ por citometría de flujo en una población adulta de donantes del Banco de Sangre del Hospital Universitario San Ignacio de Bogotá. Material y métodos: se seleccionaron 60 muestras de sangre periférica a las cuales se les analizó la población de leucocitos mediante los métodos de recuento manual total y diferencial, así como el recuento diferencial de linfocitos utilizando características morfológicas o la expresión de CD14 y CD45 por citometría de flujo. Las subpoblaciones de linfocitos fueron determinadas utilizando mareaje con tres fluorocromos para CD3, CD4 y CD8. Resultados: los porcentajes de linfocitos totales seleccionados mediante la expresión de CD45 o mediante el tamaño y la granularidad fueron similares. Los valores de linfocitos T CD3+ expresados en porcentaje presentaron un promedio de 64.9, con percentiles 5 y 95 de 50.1 - 79.4 y en valores absolutos (células/mi), el promedio fue 1358.8 células/mi, con percentiles de 743.7 - 2,259.8. Para los linfocitos TCD3+/ CD4+ en porcentaje el promedio fue de 33.8 con percentiles de 23.0 - 44.5, un promedio de 702 células con percentiles de 349.3 -1,256.3. Finalmente para los linfocitos T CD3+/CD8+ expresados en porcentaje el promedio fue 28.3 con percentiles 16.3 - 41.7 y un promedio de 555.6 células/ul con percentiles 225.7 y 1,011.2. Conclusiones: utilizando la metodología descrita en la que se combina sistemas automatizados y manuales, se demostró que los valores de linfocitos T son similares a los reportados a nivel nacional como internacional.