Introduction: Tuberculosis (TB) is an underreported condition to the Communicable Diseases Control System (CDCS). The objective of this work was to estimate the actual incidence of tuberculosis and the epidemiological characteristics of the diseases in the Zaragoza province.
Material and methods: Retrospective study in which the capture-recapture method was used to estimate the number of tuberculosis cases, by using the microbiology laboratories and the CDSC as data sources. The socio-demographic and clinical characteristics of diagnosed patients throughout three years in this province were analyzed.
Results: The mean annual incidence rate of TB was 22.02 per 100,000 inhabitants according to microbiological data, and 48.5 per 100,000 according to the capture-recapture method. A total of 569 patients were studied, and 400 of them were males (70.3%). The mean age was 43.2 years, and the 25-34 year-old group had the highest number of cases (27.9%). Twenty-three percent of cases were co-infected with HIV, and 77.4% were parenteral drug abusers, and 4.4% immigrants.
Conclusions: The capture-recapture method has demonstrated to be useful to know the relevance of TB in our setting. The actual incidence of tuberculosis was higher than that pointed out by the CDCS. Relevant differences were observed regarding incidence rates by age and sex groups. HIV infection and immigration do not appear to explain the frequency of this disease in our setting.