[Tuberculosis in a social health care center: epidemiologic study and prevention activities]

The high prevalence of infection and the often atipic presentation of tuberculosis in older people constitute an important risk factor for the nosocomial spread of the infection in the long-term care hospitals.

After a tuberculosis case, in a patient with positive sputum smears, in a long-term care hospital with 220 beds, we established a preventive programme that was based on: a) the determination, by the tuberculin test, of the prevalence of tuberculosis infection; b) the early detection of new cases of the disease, and c) the evaluation of the indications of the chemoprophylaxis.

The global prevalence of the tuberculosis infection was 44%. 16% of the patients with a significant reaction to tuberculin showed lung fibrosis in the X-ray of the thorax and 27% of them were diagnosed as active tuberculosis. During the first year of the study, the rate of illness between the infected cases was 6.45%. After 2 years the conversion rate of the tuberculin test was 6.25%.

Tuberculosis is an endemic infection in our long-term care hospital and the diagnostic delay of the active illness is an important risk factor for its dissemination. The difficulty of the interpretation of the response to the tuberculin test in old people, the evidence of the hidden illness in patients with lung fibrosis and some physic-psychological conditions of those patients, make the application of the chemoprophylaxis difficult.