Caracterización de los procedimientos para la realización de hemocultivos en pacientes adultos, en instituciones hospitalarias del Área Metropolitana del Valle de Aburrá / Characterization of procedures for performing blood cultures in adult patients, in hospitals of the Metropolitan Area of Aburrá Valley

Objetivo: Caracterizar procedimientos para la toma, análisis, reporte y aseguramiento de la calidad en hemocultivos en pacientes adultos, en instituciones hospitalarias. Material Y método: Estudio descriptivo en 15 Hospitales de Medellín y alrededores. Se empleó un formulario semiestructurado para recolectarla información, se utilizó SPSS(r) para el análisis. Resultados: Todas las instituciones tienen protocolos basados en fuentes de autoridad reconocida; con diferencias importantes en procesos pre-analíticos y postanalíticos. Los Productos más empleados para la antisepsia fueron gluconato declorhexidina al 2-4%(66,7%) Y alcohol isopropílico o etílico al 70% (20,0%),Con discrepancias en los tiempos de acción. El 73,3% emplea guantes estériles y la misma proporción usa sistema abierto (jeringa) para la venopunción. En el 46,6% se toman dos botellas aerobias y una anaerobia por episodio y en 33,3% dos botellas aerobias. El 66,6% lleva un indicador de contaminación, 53,3% de positividad y 26,6% de volumen de sangre. La tasa promedio de hemocultivos contaminados durante el semestre de seguimiento fue 1,61%. Conclusión: Se observa heterogeneidad en los procedimientos, especialmente en fases pre-analítica y post-analítica. En La búsqueda de la excelencia y la seguridad del paciente son necesarios protocolos estandarizados e indicadores para medir y controlar el desempeño de los hemocultivos.

Objective: To characterize the procedures that are performed for the collection, analysis, reporting and quality assurance of blood cultures in adult patients in hospital institutions. Material and Methods: Descriptive study in 15 hospitals of Medellin and its surroundings. A semi-structured collection instrument was used to collect the information provided by each hospital; SPSS(r) was used for the analysis. Results: All Institutions have protocols based o nauthorized sources; there were important differences in the pre-analytic and post-analytic processes. The Products employed for skin antisepsis were2-4% Chlorhexidine gluconate (66.7%)And70% Isopropyl or ethyl alcohol(20.0%), with discrepancies in product action times. 73.3% use sterile gloves and an equal proportion uses an open system (syringe) for venipuncture. Two aerobic and one anaerobic bottles are taken per episode in adult patients in 46.6% of institutions and only two aerobic bottles in 33.3% of them. Indicators of contamination were used by 66.6 % of institutions, of positivity in 53.3% and of blood volume in 26.6%. The average rate of contaminated blood cultures during the follow-up period was 1.61%. Conclusion: Heterogeneity in the procedures was observed especially in the pre-analytic and post-analytical phases. In the pursuit of excellence and patient safety, standardized protocols and the use of indicators to measure and control the performance of blood cultures are needed.

Validation and clinical application of a molecular method for the identification of Cryptococcus neoformans/Cryptococcus gattii complex DNA in human clinical specimens

ABSTRACT The diagnosis of cryptococcosis is usually performed based on cultures of tissue or body fluids and isolation of the fungus, but this method may require several days. Direct microscopic examination, although rapid, is relatively insensitive. Biochemical and immunodiagnostic rapid tests are also used. However, all of these methods have limitations that may hinder final diagnosis. The increasing incidence of fungal infections has focused attention on tools for rapid and accurate diagnosis using molecular biological techniques. Currently, PCR-based methods, particularly nested, multiplex and real-time PCR, provide both high sensitivity and specificity. In the present study, we evaluated a nested PCR targeting the gene encoding the ITS-1 and ITS-2 regions of rDNA in samples from a cohort of patients diagnosed with cryptococcosis. The results showed that in our hands, this Cryptococcus nested PCR assay has 100% specificity and 100% sensitivity and was able to detect until 2 femtograms of Cryptococcus DNA.

Validation and clinical application of a nested PCR for paracoccidioidomycosis diagnosis in clinical samples from Colombian patients

Paracoccidioidomycosis is a systemic and endemic mycosis, restricted to tropical and subtropical areas of Latin America. The infection is caused by the thermal dimorphic fungus Paracoccidioides brasiliensisand Paracoccidioides lutzii. The diagnosis of paracoccidioidomycosis is usually performed by microscopic examination, culture and immunodiagnostic tests to respiratory specimens, body fluids and/or biopsies; however these methods require laboratory personnel with experience and several days to produce a result. In the present study, we have validated and evaluated a nested PCR assay targeting the gene encoding the Paracoccidioides gp43membrane protein in 191 clinical samples: 115 samples from patients with proven infections other than paracoccidioidomycosis, 51 samples as negative controls, and 25 samples from patients diagnosed with paracoccidioidomycosis. Additionally, the specificity of the nested PCR assay was also evaluated using purified DNA isolated from cultures of different microorganisms (n= 35) previously identified by culture and/or sequencing. The results showed that in our hands, this nested PCR assay for gp43 protein showed specificity and sensitivity rates of 100%. The optimized nested PCR conditions in our laboratory allowed detection down to 1 fg of P. brasiliensisDNA.