Short course chemoprophylaxis with rifampicin, isoniazid and pyrazinamide for tuberculosis evaluated in gold miners with chronic silicosis: a double-blind placebo controlled trial.

SETTING: A medical facility for approximately 90,000 gold miners employed on 24 South African gold mines. OBJECTIVE: To evaluate the effectiveness of rifampicin, isoniazid and pyrazinamide given for 3 months for the prevention of tuberculosis in men with silicosis. DESIGN: A randomised double-blind placebo controlled trial with active 4-year follow up of subjects by routine radiographic screening. RESULTS: A total of 382 gold miners with silicosis were randomised to receive rifampicin 600 mg, isoniazid 400 mg and pyrazinamide 1.25 g daily as Rifater or a placebo. These men have been followed for 4 years since the end of the treatment period. Eleven men who received the combination tablet and 15 men who received the placebo tablet have developed tuberculosis (chi 2 df1 = 0.66, P = 0.4). CONCLUSION: This multi-drug short course chemoprophylaxis regimen has failed to prevent tuberculosis in miners with silicosis. Even if a larger study had demonstrated a statistically significant effect of the regimen as compared with placebo, the rate of tuberculosis in the men who received the three-drug regimen was unacceptably high.

[Roentgenological diagnosis of silicotuberculosis]. / Rentgenodiagnostika silikotuberkuleza.

Possibilities of roentgenologic method of examination with the use of roentgenography and tomography in the diagnosis of current forms of silicotuberculosis and tuberculosis in workers of the industries highly exposed to silicosis are analysed. ++Clinico-roentgenological+ pictures of 305 patients were studied in their dynamics for the period of 3 to 10 years. Being characterized by a benign course, silicotuberculosis is most often diagnosed in persons who left their work. A follow-up at least at 6-month intervals is of great importance in assessing its activity.

An attempt to eradicate silicotuberculosis in Ottawa County, Oklahoma.

In 1974 and 1975, a selective tuberculosis screening program was conducted in a small mining community in Ottawa County, Oklahoma. Former miners, 50 years of age and over, who had abnormal chest radiographs consistent with silicosis or inactive tuberculosis and positive tuberculin skin tests, were offered isoniazid preventive therapy. Since the project ended, morbidity from silicotuberculosis has declined but silicotuberculosis has continued to occur. In this report, we examine the reasons for the failure to eradicate this disease from the community.

[Aspects of tuberculosis prevention in the industrial environment]. / Aspecte ale luptei antituberculoase in mediul industrial.

The dynamics were studied of the tuberculous endemy in a limited area of the Cluj-Napoca District over a period of 5--16 years. An industrial environment was considered in comparison with a non-industrial one in the vicinity. The results show a marked decrease in the incidence of tuberculosis in the industrial environment (from 710 0/0000 in 1961 to 102 3/0000 in 1976), but, at the same time, it was demonstrated that morbidity due to tuberculosis is higher as compared with the non-industrial area (318 0/0000 as compared with 49 0/0000). The importance is discussed, of some particular factors of the industrial environment, such as pneumoconioses -- of which the most important are those due to silica -- which are significant risk factors for tuberculosis. A close cooperation is recommended, between enterprise physicians and pneumophtysiologists working in territorial polyclinics.

[Preventive chemotherapy in persons with silicosis and silicotuberculosis (author's transl)]. / Präventive Chemotherapie bei Silikose und Silikotuberkulose

In some countries extensive research is carried out on preventing tuberculous disease by administration of INH. In GDR since about 1960 chemopreventive measures were taken in cases of silicosis and silicotuberculosis too. More than 2000 patients of the Magdeburg Pneumoconiosis Center were followed-up from 1960 to 1969. The high risk of tuberculous disease of 21% in the group of silicosis patients without administration of INH could be reduced to 14% after preventive administration of INH. However, such clear effects were observed only under optimal conditions, that is sufficient dosage, duration and reliability of treatment. On the base of these results and other publications patients with silicosis with and without tuberculous residues should be included into the programmes of preventive chemotherapy of the chest clinics.