[Tuberculosis epidemiology in area 15 of the Spanish autonomous community of Valencia: evolution from 1987 through 2001]

Abstract

Objectives: To describe the evolution of tuberculosis epidemiology in Area 15 of the Autonomous Community of Valencia.

Material and methods: Cases of tuberculosis were identified by active case finding in Area 15 from January 1987 through December 2001. Clinical and epidemiological data were extracted from case records and a patient interview.

Results: Four hundred seventy-six diagnosed cases of mycobacterial infection were identified (459 tuberculosis, 16 atypical, and 1 mixed); 423 tuberculosis patients were residents of Area 15. The mean annual incidence rate was 24.6/100 000 population, representing a rate decrease of 41.5% from 1990. The most frequent risk factors were smoking (38%), alcoholism (20%), human immunodeficiency virus (HIV) infection (18%), and contact with a tuberculosis patient (14%). The site of tuberculosis involvement was the lung in 61% (49% bacillus positive, with a nonsignificant trend to decrease over time), nonpulmonary in 26%, and mixed in 13%. The radiographic pattern observed most often was pulmonary infiltrates (67%), and lower lobe involvement tended to increase over time. Diagnosis was by acid-fact bacillus stain for 77%, clinical picture for 16%, and histological for 7%. Isoniazid resistance was detected in 1.5% and rifampicin resistance in 0.3%. Patients were hospitalized during diagnosis in 79% of cases; the mean stay was 18 days.

Conclusions: The incidence of tuberculosis has decreased in spite of the HIV pandemic. Risk factors have not changed, bacteriological diagnosis has improved, and the location of pulmonary infiltrates has changed. No influence of immigration on the incidence rate of tuberculosis has been detected to date.