Role of QuantiFERON(®)-TB Gold In-Tube in tuberculosis contact investigation: experience in a tuberculosis unit.

BACKGROUND: Interferon-γ release assays (IGRAs) are increasingly used for the diagnosis of latent tuberculosis infection (LTBI). Because of the lack of a gold standard for the diagnosis of LTBI, IGRAs are compared to the tuberculin skin test (TST) and yield conflicting results. We assessed the usefulness of an IGRA test, QuantiFERON(®)-TB Gold In-Tube (QFT-G-IT), for diagnosing LTBI compared with TST in the setting of a contact screening study. METHODS: A prospective comparison between the QFT-G-IT and the TST in TB contact subjects in a low TB burden area was conducted sequentially between January 2006 and December 2012. RESULTS: A moderate concordance between the two tests (κ = 0.44 for TST cut-off of 5 mm and κ = 0.56 for TST cut-off of 15 mm) was found. A better agreement was shown in younger contacts and in non-vaccinated contacts when using a TST of 15 mm. Independent risk factors for a TST(+)/QFT-G-IT(-) discordance were history of BCG vaccination and age between 31 and 59 years. Discordance was also more frequent using a TST cut-off value of 5 mm. QFT-G-IT(+)/TST(-) was infrequent and was found in older contacts. CONCLUSIONS: Based on our data, we cannot recommend the use of QFT-G-IT as the only test to rule out LTBI, especially in older patients.

Experiencia de una unidad monográfica de tuberculosis: primeros 500 casos / Experience of a Monographic Tuberculosis Unit: The First 500 Cases

Introducción: La tuberculosis (TB) continúa siendo una enfermedad muy prevalente aunque desde el año 2002 el número de casos anuales muestra una tendencia decreciente en el mundo y también en nuestro país, donde la incidencia es muy variable entre comunidades autónomas. El objetivo principal de este estudio es describir la experiencia de una unidad monográfica de TB de un centro hospitalario de segundo nivel. Pacientes y métodos: Estudio descriptivo de los casos de TB diagnosticados en una unidad monográfica de un hospital secundario entre 2003 y 2011. Se recogieron datos demográficos, clínicos, epidemiológicos y microbiológicos para su análisis. Resultados: Se analizaron 500 casos de TB, encontrando una incidencia anual creciente en todos los subgrupos, incluyendo población autóctona e inmigrante. La mayoría (63,8%) eran varones, con una mediana de edad de 36 años (rango 8 meses-90 años). Un 39,8% de los pacientes era inmigrante. En un 11% de los casos existía coinfección con el virus de la inmunodeficiencia humana. La localización fue pulmonar en el 63,8% de los casos. La letalidad global fue del 5,8% sin encontrar diferencias significativas entre subgrupos (incluyendo población inmigrante y personas infectadas por el virus de la inmunodeficiencia humana). Conclusiones: A pesar de la tendencia descendente global en cuanto al número de casos de TB declarados, en nuestra serie esta es creciente en todos los subgrupos. La existencia de una unidad monográfica de TB junto con un exhaustivo programa de estudio de contactos podría explicar este hallazgo (AU)

Introduction: Tuberculosis (TB) remains a highly prevalent and potentially severe disease. However, since 2002 the annual incidence has been decreasing both worldwide and in Spain, where the incidence varies widely between regions. The main objective of this study is to describe the experience of a monographic TB unit in a second level hospital. Patients and methods: A descriptive study was carried out which included all cases of TB diagnosed in a monographic unit of a secondary hospital between 2003 and 2011. Demographic, clinical, epidemiological and microbiological data were recorded. Results: We analyzed 500 TB cases and found an increasing annual incidence in all subgroups, including native and immigrant populations. Most cases (63.8%) were male, with a median age of 36 years (range 8 months–90 years). In total, 39.8% of patients were foreign born. Coinfection with human immunodeficiency virus (HIV) was found in 11.0% of cases. The pulmonary form was most frequently diagnosed (63.8%). Overall mortality was 5.8% with no significant differences between groups (including foreign born and HIV positive patients). Conclusions: Although TB incidence is globally decreasing, in our study we found an increasing number of cases in recent years in all subgroups, which can be explained by this being a monographic unit with an intensive contact tracing program (AU)

Experience of a monographic tuberculosis unit: the first 500 cases.

INTRODUCTION: Tuberculosis (TB) remains a highly prevalent and potentially severe disease. However, since 2002 the annual incidence has been decreasing both worldwide and in Spain, where the incidence varies widely between regions. The main objective of this study is to describe the experience of a monographic TB unit in a second level hospital. PATIENTS AND METHODS: A descriptive study was carried out which included all cases of TB diagnosed in a monographic unit of a secondary hospital between 2003 and 2011. Demographic, clinical, epidemiological and microbiological data were recorded. RESULTS: We analyzed 500 TB cases and found an increasing annual incidence in all subgroups, including native and immigrant populations. Most cases (63.8%) were male, with a median age of 36 years (range 8 months-90 years). In total, 39.8% of patients were foreign born. Coinfection with human immunodeficiency virus was found in 11% of cases. The pulmonary form was most frequently diagnosed (63.8%). Overall mortality was 5.8% with no significant differences between groups (including foreign born and human immunodeficiency virus positive patients). CONCLUSIONS: Although TB incidence is globally decreasing, in our study we found an increasing number of cases in recent years in all subgroups, which can be explained by this being a monographic unit with an intensive contact tracing program.

Valor de QuantiFERON-TB Gold Test in Tube en el diagnóstico de tuberculosis pulmonar y extrapulmonar / Quantiferon-TB-gold in tube test in the diagnosis of pulmonary and extra-pulmonary tuberculosis

Introducción Los test de detección in vitro de Interferón-gamma frente a Mycobacterium tuberculosis (MTB) podrían ser una herramienta útil en el diagnóstico de enfermedad tuberculosa activa. Métodos Se realiza el test QuantiFERON-TB-Gold test in Tube (QFG-IT) en la sangre de 118 pacientes con tuberculosis pulmonar activa y se compara el resultado con la prueba de tuberculina. Resultados El estudio de QFG-IT fue positivo en 94 casos (79,7%), negativo en 17 (14,4%) e indeterminado en 7 (5,9%). QFG-IT negativo o indeterminado fue más frecuente en pacientes más ancianos (p=0,017) y en los casos de baciloscopia (..) (AU)

Introduction: The Interferon-gamma in vitro detection tests could be a useful tool in the diagnosis of active tuberculosis compared to Mycobacterium tuberculosis (MTB). Methods: The QuantiFERON-TB-Gold in Tube (QFG-IT) test was performed on the blood of 118 patients with active tuberculosis and the results compared with the tuberculin test. Results: The QFG-IT test was positive in (..) (AU)

[Quantiferon-TB Gold In-Tube test in the diagnosis of pulmonary and extra-pulmonary tuberculosis]. / Valor de QuantiFERON-TB Gold Test in Tube en el diagnóstico de tuberculosis pulmonar y extrapulmonar.

INTRODUCTION: The Interferon-γ in vitro detection tests could be a useful tool in the diagnosis of active tuberculosis compared to Mycobacterium tuberculosis (MTB). METHODS: The QuantiFERON-TB-Gold in Tube (QFG-IT) test was performed on the blood of 118 patients with active tuberculosis and the results compared with the tuberculin test. RESULTS: The QFG-IT test was positive in 94 cases (79.7%), negative in 17 (14.4%) and indeterminate in 7 (5.9%). A negative or indeterminate QFG-IT test was more common in older patients (P=0.017) and in cases with negative smear tests (P=0.041). The kappa agreement between the tuberculin and QFG-IT tests was 74.5% with a kappa value of 0.45 (SE:0.136). Thirteen of the patients studied were infected with HIV and the tuberculin was positive in 5 of the 12 cases (38.5%) in whom it was performed, with the QFG-IT being positive in 9/13 (69.2%). CONCLUSIONS: The QFG-IT test may be a useful complimentary tool to the tuberculin test in the diagnosis of tuberculosis.