Epidemiological Analysis of Tuberculous Lymphadenopathy in a District of Barcelona: Proposal of a Diagnostic Algorithm

Background: Barcelona (Spain) has experienced a dramatic change in its demography, which is reflected in the local epidemics of tuberculous lymphadenopathy (TL). The objective of the study is to analyze the associated risk factors to TL in a district of Barcelona with an incidence above 50 cases per 10,000 inhabitants/year, which will help to construct a diagnostic algorithm. Methods: single-centre retrospective cohort study of all cases of TL diagnosed between 1990 and 2009. Due to the demographic changes, we analyzed 2 separate study periods (1990-1999 and 2000-2009). Socio-demographic, clinical and diagnostic features were assessed and compared between both cohorts and the algorithm was constructed with these results. Data was obtained from all the patients diagnosed with TL in Hospital del Mar (Barcelona) and was sent to the Public Health Agency of Barcelona. Results: in the first study period, 152 patients had TL (73.7% Spanish-born) and in the second study period 147 (70.7% immigrants). In the first period, the percentage of male immigrants was 70.5% and 57.1% were younger than 35 years old but in the second study period, there was a 58.1% of Spanish-born female patients and 69.8% above 35 years old. The percentage of HIV co-infection decreased from 69.9% to 44.2% in the second period but use of immunosuppressive treatment increased to 9.3% in Spanish-born patients. Multivariate analysis showed intravenous drug use (OR 8.2; 95%CI: 3.4-19.8) and immigrant status (OR 4.8; 95%CI: 2.7-8.3) as risk factors associated to TL. Conclusion: male immigrants arriving from areas with high burden of TB, younger than 35 years old and Spanish-born women, older than 35 years old, with HIV infection (although with a lower proportion than before year 2000) or receiving immunosuppressive treatment, are the groups with an increased risk of TL in our district.