Demora diagnóstica como principal factor contribuyente a un importante brote de tuberculosis en una universidad / Diagnostic delay as main contributing factor to a large outbreak of tuberculosis in a university

OBJETIVO: Describir las características epidemiológicas de un importante brote de tuberculosis en el ámbito universitario y los principales factores de riesgo asociados. MÉTODO: Se realizó un análisis descriptivo de los datos recogidos de las personas enfermas y de los contactos. Para el estudio de contactos se siguieron las pautas establecidas en el Programa de Tuberculosis de la Comunidad Autónoma del País Vasco. Seis de las cepas del brote fueron enviadas al Centro Nacional de Microbiología para su tipado molecular. RESULTADOS: El número total de casos del brote fue de 11. La tasa de infección tuberculosa en el aula del caso índice, incluidas las personas enfermas, fue del 88,1% (59 infectados y solo 8 no infectados). La demora diagnóstica del caso índice fue de 260 días, y en los otros 8 casos sintomáticos osciló entre 10 y 70 días. El patrón obtenido por las 2 técnicas de genotipado fue idéntico en las 6 cepas estudiadas. CONCLUSIONES: La gran demora diagnóstica del caso índice auténtico, que se diagnosticó en el estudio de contactos, y las malas condiciones de ventilación del aula determinaron el alto número de casos secundarios asociados a este brote

OBJECTIVE: To describe the epidemiological characteristics of a large tuberculosis outbreak in the university environment and the main risk factors associated with it. METHOD: A descriptive analysis of the data collected from sick individuals and their contacts was made. For the contact tracing, the guidelines established in the Tuberculosis Programme of the Autonomous Community of the Basque Country were followed. Six of the outbreak strains were sent to the National Centre of Microbiology for molecular typing. RESULTS: The total number of cases of the outbreak was 11. The rate of tuberculosis infection in the classroom of the index case, including the sick individuals, was 88.1% (59 infected and only 8 uninfected). The diagnostic delay of the index case was 260 days, and in the other 8 symptomatic cases it ranged between 10 and 70 days. The pattern obtained by the 2 genotyping techniques was identical in the 6 strains studied. CONCLUSIONS: The long diagnostic delay of the authentic index case, which was diagnosed in the contact tracing, and the poor ventilation conditions of the classroom, determined the high number of secondary cases associated with this outbreak

Diagnostic delay as main contributing factor to a large outbreak of tuberculosis in a university. / Demora diagnóstica como principal factor contribuyente a un importante brote de tuberculosis en una universidad.

OBJECTIVE: To describe the epidemiological characteristics of a large tuberculosis outbreak in the university environment and the main risk factors associated with it. METHOD: A descriptive analysis of the data collected from sick individuals and their contacts was made. For the contact tracing, the guidelines established in the Tuberculosis Programme of the Autonomous Community of the Basque Country were followed. Six of the outbreak strains were sent to the National Centre of Microbiology for molecular typing. RESULTS: The total number of cases of the outbreak was 11. The rate of tuberculosis infection in the classroom of the index case, including the sick individuals, was 88.1% (59 infected and only 8 uninfected). The diagnostic delay of the index case was 260 days, and in the other 8 symptomatic cases it ranged between 10 and 70 days. The pattern obtained by the 2genotyping techniques was identical in the 6 strains studied. CONCLUSIONS: The long diagnostic delay of the authentic index case, which was diagnosed in the contact tracing, and the poor ventilation conditions of the classroom, determined the high number of secondary cases associated with this outbreak.

Estudio comparativo de QuantiFERON ®-TB Gold IT frente a tuberculina para el diagnóstico de la infección tuberculosa latente en estudios de contactos / Comparative performance of QuantiFERON ®-TB Gold IT versus Tuberculin Skin Test among contact investigations for latent tuberculosis infection

Fundamento y objetivo: Hasta hace poco, la única técnica disponible para diagnosticar la infección tuberculosa latente (ITL) era la tuberculina (PPD). QuantiFERON®-TB Gold In-Tube (QF), al igual que otros métodos diagnósticos basados en la liberación de interferón-γ (IGRA), aparecen como una alternativa a la PPD. El objetivo del estudio es comparar ambas técnicas (PPD y QF) para evaluar la utilidad diagnóstica y factibilidad del uso rutinario de QF en estudios de contactos. Pacientes y método: Estudio descriptivo prospectivo de concordancia entre PPD y QF a partir de contactos de pacientes con tuberculosis confirmada mediante cultivo entre mayo de 2007 y febrero de 2008 en Bizkaia y Araba, estimándose la concordancia mediante el estadístico kappa (κ).Resultados: Se hallaron 376 contactos: 8 niños (edad ≤ 14 años) de alto riesgo, 30 niños de riesgo bajo-medio, 46 adultos (edad > 14 años) de alto riesgo y 270 adultos de riesgo bajo-medio. Un total de 160 contactos (42,5%) fueron PPD+ para PPD ≥ 5mm, 141 (37,5%) para PPD ≥ 10mm y 95 (25,3%) para PPD ≥ 15mm. Mediante QF se obtuvieron 94 positivos, 279 negativos y tres indeterminados. Aunque en conjunto hay buena concordancia para PPD ≥ 10mm (κ=0,53; p < 0,0001), hubo pobre concordancia cuando el caso índice era no bacilífero para PPD ≥ 5mm (κ=0,28; p<0,001) y en contactos de alto riesgo para PPD ≥ 15mm (κ=0,048; p=0,36). Conclusiones: Frente a PPD, los IGRA constituyen una excelente herramienta en Salud Pública para el diagnóstico de la ITL, proporcionando un diagnóstico más específico, reduciendo el número potencial de tratamientos y mejorando el aprovechamiento de recursos sanitarios (AU)

Background and objective: Until recently, the only tool for detection of latent tuberculosis infection (LTI) was the tuberculin skin test (PPD). QuantiFERON®-TB Gold In-Tube (QF), as well as other Mycobacterium tuberculosis-specific interferon-γ release assays (IGRAs), appears to be an alternative or adjunct to the PPD. The goal of the study was to compare QF with PPD to evaluate de accuracy of QF for routinely identifying LTI in contact investigations. Patients and method:We performed a descriptive and prospective study with contacts of culture-confirmed tuberculosis source cases in Bizkaia and Araba from May 2007 through February 2008 who underwent QF and PPD. Concordance between both tests was analyzed using the kappa statistic (κ). Results: 376 contacts were found: 8 were high-risk children (age < 15), 30 low-medium risk children, 46 high-risk adults (age>14) and 270 low-medium risk adults. PPD was positive in 160 subjects (42.5%) at PPD ≥ 5mm, 141 (37.5%) at PPD ≥ 10mm and 95 (25.3%) at PPD ≥ 15mm. In QF analysis 94 subjects were positive, 279 negative and 3 indeterminate. Overall agreement between QF and PPD was good at PPD ≥ 10mm (κ=0.53; p<0.0001) but agreement was poor when the index case had positive baciloscopy at PPD ≥ 5mm (κ=0.28; p<0.001) and high-risk contacts at PPD ≥ 15mm (κ=0.048; p=0.36). Conclusions: IGRAs are an accurate indicator of LTI, providing a more specific way of diagnostic and reducing the number of subjects to be treated. QF appears to be a valuable public health tool with potential advantages over the PPD and improving resources (AU)

[Comparative performance of QuantiFERON(®)-TB Gold IT versus tuberculin skin test among contact investigations for latent tuberculosis infection]. / Estudio comparativo de QuantiFERON(®)-TB Gold IT frente a tuberculina para el diagnóstico de la infección tuberculosa latente en estudios de contactos.

BACKGROUND AND OBJECTIVE: Until recently, the only tool for detection of latent tuberculosis infection (LTI) was the tuberculin skin test (PPD). QuantiFERON(®)-TB Gold In-Tube (QF), as well as other Mycobacterium tuberculosis-specific interferon-γ release assays (IGRAs), appears to be an alternative or adjunct to the PPD. The goal of the study was to compare QF with PPD to evaluate de accuracy of QF for routinely identifying LTI in contact investigations. PATIENTS AND METHOD: We performed a descriptive and prospective study with contacts of culture-confirmed tuberculosis source cases in Bizkaia and Araba from May 2007 through February 2008 who underwent QF and PPD. Concordance between both tests was analyzed using the kappa statistic (κ). RESULTS: 376 contacts were found: 8 were high-risk children (age < 15), 30 low-medium risk children, 46 high-risk adults (age>14) and 270 low-medium risk adults. PPD was positive in 160 subjects (42.5%) at PPD ≥ 5mm, 141 (37.5%) at PPD ≥ 10mm and 95 (25.3%) at PPD ≥ 15 mm. In QF analysis 94 subjects were positive, 279 negative and 3 indeterminate. Overall agreement between QF and PPD was good at PPD ≥ 10mm (κ=0.53; p<0.0001) but agreement was poor when the index case had positive baciloscopy at PPD ≥ 5mm (κ=0.28; p<0.001) and high-risk contacts at PPD ≥ 15 mm (κ=0.048; p=0.36). CONCLUSIONS: IGRAs are an accurate indicator of LTI, providing a more specific way of diagnostic and reducing the number of subjects to be treated. QF appears to be a valuable public health tool with potential advantages over the PPD and improving resources.

Resultados del tratamiento antituberculoso en seis comunidades autónomas españolas / Results of anti-tuberculosis treatment in six autonomous regions in Spain

FUNDAMENTO: Analizar los resultados del tratamiento antituberculoso. PACIENTES Y MÉTODO: Se realizó un estudio de cohortes retrospectivo en 6 comunidades autónomas (CCAA), Asturias, Cataluña, Galicia, La Rioja, Murcia y País Vasco, utilizando la cohorte de casos iniciales de tuberculosis identificados a través del PMIT que no se encontraran en prisión en el momento del diagnóstico (abril 1996-mayo 1997). La información se obtuvo de la historia clínica, y se siguieron las definiciones y normas para el análisis recomendadas para Europa. RESULTADOS: Cumplieron los criterios de inclusión en el estudio un total de 4.899 enfermos tuberculosos, de los que 4.240 (86,6 por ciento) tenían información suficiente en la historia clínica para conocer el resultado del tratamiento. Se constató un resultado satisfactorio en 3.417 pacientes (69,7 por ciento), 438 (8,9 por ciento) murieron antes de iniciar el tratamiento o durante su transcurso y 1.044 (21,4 por ciento) cumplieron la definición de resultado potencialmente insatisfactorio. Se hallaron variaciones importantes por CCAA y también según nacionalidad, grupo de edad, infección por el VIH, uso de drogas por vía parenteral, antecedentes de alcoholismo y localización de la enfermedad. CONCLUSIONES: De acuerdo a la información obtenida en este estudio, los resultados del tratamiento antituberculoso en las áreas analizadas no alcanzan los niveles recomendados por la Organización Mundial de la Salud (OMS) para lograr un control efectivo de la enfermedad. Sería preciso, por tanto, analizar las causas y plantear medidas para mejorar la situación (AU)