[Factors related to the tuberculous patient and the study of contacts]

While the maximum priority of the programs for tuberculosis prevention and control is the identification and treatment of all the people with active tuberculosis, the second priority is the evaluation of their contacts. The goal of this study has been to evaluate the factors of the tuberculous patients associated with the study of their contacts.

The incident cases of tuberculosis occurred during the period 1992-1997 in the province of Lleida were studied. The variables of the study were: age, sex, place of residence, infection by HIV, parenteral drug use (PDU), excessive alcohol consumption, anatomical location of tuberculosis, existence of cavernous lesions in the chest X-ray, and microbiological result of the samples of respiratory secretions. The association of the dependent variable (study of the contacts in the incident cases of tuberculosis) with the rest of independent variables it was determined by the raw and adjusted odds ratio.

The prevalence of tuberculosis patients whose contacts were studied was 60.4% (63.1% in the bacilliferous cases and 51.9% in the non-bacilliferous cases, p=0.003). A higher number of patients whose contacts were studied was detected between those that were not HIV-infected (ORa: 4.53; 95% CI: 2.91-7.05), between those with lung as the anatomical localization of the tuberculous disease (ORa: 2.62; 95% CI: 1.70-4.05) and between those that did not showed excessive alcohol consumption (ORa: 1.69; 95 CI: 1.17-2.46).

The global prevalence of tuberculous whose contacts are studied should be increased, especially among the patients with sociosanitary risk (HIV, PDU and alcoholism), and among the patients with higher probability of transmission.