Silicotuberculosis: long-term outcome after short-course chemotherapy.
METHODS
A medical facility for approximately 90,000 gold miners employed on 24 South African gold mines.


OBJECTIVE
To establish the long-term risk attributable to silicosis of relapse from pulmonary tuberculosis treated with short-course chemotherapy.


METHODS
A consecutive sample of gold miners with pulmonary tuberculosis allocated to receive rifampicin, isoniazid, pyrazinamide and streptomycin given on weekdays for 5 months. Radiographs were assessed at the time of diagnosis for the presence of silicosis. All of the men were followed for at least 5 years after completing their treatment, or until they left mine service or suffered a relapse of tuberculosis.


RESULTS
The sample included 549 men of whom 167 had silicosis. The incidence density for relapse in silicosis was 1.55 (95% CI 0.97, 2.48) times that for the men without silicosis. There was no difference in the pattern of relapse over time between the two groups: the mean period to relapse in the men with silicosis was 2.6 years (SD 1.89 years) and for the men without silicosis was 3.1 years (SD 2.23 years) (P = 0.6).


CONCLUSIONS
Silicosis causes a small increase in the risk of relapse of tuberculosis. Relapses in both groups were not confined to the first 2 years after completion of treatment.
Cowie
R L
RL
Department of Medicine, Ernest Oppenheimer Hospital, Welkom, South Africa.
D000328:Adult; D000995:Antitubercular Agents / Q000008:administration & dosage*; D004359:Drug Therapy, Combination / Q000008:administration & dosage*; D005500:Follow-Up Studies; D006801:Humans; D007538:Isoniazid / Q000008:administration & dosage; D008297:Male; D011718:Pyrazinamide / Q000008:administration & dosage; D012008:Recurrence; D012293:Rifampin / Q000008:administration & dosage; D012830:Silicotuberculosis / Q000188:drug therapy*; D013307:Streptomycin / Q000008:administration & dosage; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy
D000995:Antitubercular Agents; D011718:Pyrazinamide; D007538:Isoniazid; D012293:Rifampin; D013307:Streptomycin