Extrapulmonary tuberculosis: epidemiology and risk factors

RESUMEN

Objetivo: Conocer la epidemiología y los factores de riesgo asociados con la tuberculosis extrapulmonar(EPTB).Método: Los casos de tuberculosis (TB) diagnosticadas entre 1991-2008 en una población caucásica fueron clasificados como EPTB o TB pulmonar (PTB). De todos los casos, 63,7% fueron seguidos en una consulta monográfica de TB. Se utilizó un protocolo estandarizado para la recogida de los datos, incluyendo sexo, edad, vacunación con BCG, contacto con algún paciente con PTB, tabaquismo, alcoholismo, diabetes mellitus, corticoides/fármacos inmunosupresores e infección por el VIH. Se compararon las variables entre los grupos de EPTB y de PTB. El análisis estadístico se basó en un estudio de regresión logística. Se calcularon los odds ratio (OR) y sus intervalos de confianza (IC) del 95%.Resultados: Entre 2.161 casos diagnosticados, 1.186 fueron PTB y 705 EPTB. La incidencia global de TB disminuyó desde 79.9/100.000 en 1992 hasta 27.1/100.000 en 2008, p<0,05. El número de casos de EPTB disminuyó de forma más lenta que el de PTB. La proporción de EPTB aumentó desde 30,6% de los casos en 1991-1996 hasta 37,6% en 2003-2008 (la localización ganglionar aumentó un 27%), p<0,05 en un ji al cuadrado de tendencia. En el estudio multivariante, ser mujer (OR 2,04; IC 95% 1,56-2,66) y la edad (OR1,02; IC 95% 1,01-1,022) se asociaron con EPTB mientras que el alcoholismo (OR 0,33; IC 95% 0,20-0,52),

ABSTRACT

Objective To describe the epidemiology and risk factors associated with extra-pulmonary tuberculosis (EPTB).Method Cases of tuberculosis (TB) diagnosed from 1991 to 2008 in a Caucasian population were classified as EPTB or pulmonary TB (PTB). Of all cases, 63.7% were followed up in a specialist TB unit. A standardised protocol for data collection was used, including gender, age, BCG vaccination, contact with PTB patient, smoking habit, alcohol abuse, diabetes mellitus, immunosuppressive drugs/steroids and HIV-status. These variables were compared between EPTB and PTB groups. Statistical analysis was based on logistic regression. Odds ratios (OR) and their 95% confidence intervals (CI) were calculated. Results Among the 2,161 cases diagnosed, 1,186 were PTB and 705 EPTB. The overall TB incidence had fallen from 79.9/100,000 in 1992 to 27.1/100,000 in 2008, P<.05. The number of EPTB cases decreased more slowly than PTB. EPTB increased from 30.6% of cases in 1991-1996 to 37.6% in 2003-2008 (lymphatic site increased 27%), by trend test P<.05. At multivariate level, being female (OR 2.04; 95% CI 1.56-2.66) and age (OR 1.02; 95% CI 1.01-1.022) were associated with EPTB, while alcohol abuse (OR 0.33; 95% CI 0.20-0.52), smoking habit (OR 0.45; 95%CI 0.34-0.59), contact with PTB patients (OR 0.57; 95% CI 0.44-0.76) and BCG vaccination (OR 0.64; 95% CI 0.44-0.92) had a protective effect. The proportion of female gender and age of patients increased over time, whilst there was a decrease in BCG vaccinated patients. Conclusions Whilst there has been a reduction in the overall incidence of TB, the proportion of EPTB increased. The proportional increase in EPTB could be explained by an increase in life expectancy and the predominance of women in the population, and by a decline in BCG vaccinated patients(AU) el tabaquismo (OR 0,45; IC 95% (..) (AU)