Sociodemographic predictors and temporal trends of extrapulmonary tuberculosis as an AIDS-defining disease in Spain

Abstract

Objective: To identify the factors associated with the presentation of extrapulmonary tuberculosis (EPTB) in AIDS diagnosis and to analyse its temporal trend.

Design: Analysis of AIDS surveillance data.

Methods: The study was based on AIDS cases diagnosed in Spain between 1988 and 1993, and reported up to September 1994. The proportion of patients presenting with EPTB at AIDS diagnosis was analysed by sociodemographic characteristics and year of diagnosis.

Results: Of the 22,445 AIDS cases diagnosed in Spain from 1988 to 1993, 6526 patients (29.1%; 95% confidence interval, 28.5-29.7) presented with EPTB at diagnosis, making it the most frequent AIDS-defining disease. The highest proportions of EPTB reported at AIDS diagnosis were observed for injecting drug users (IDU; 35.4%) and the heterosexual transmission category (23.5%). The proportion of EPTB was lower in women [relative risk (RR), 0.85; P < 0.001], and higher in 15-29-year-olds (34.2%) and patients with a prison record (44.3 versus 25.4%; RR, 1.75; P < 0.001). AIDS patients resident in provinces with high respiratory TB mortality rates among the general population exhibited a higher proportion of EPTB (RR, 1.45; P < 0.001). The effect of any one variable was maintained by controlling for all others. The proportion of patients with EPTB at AIDS diagnosis revealed a downward trend from 1988 to 1993 (P = 0.007), which was observed in IDU and heterosexuals but not in homosexual/bisexual men (P = 0.421).

Conclusions: Factors such as injecting drug use, prison record or residence in high TB-endemic areas are associated with a greater frequency of EPTB at AIDS diagnosis. These factors must be considered for specific prophylaxis to be efficiently applied.