Concurrent Silicosis and Pulmonary Mycosis at Death

To examine risk for mycosis among persons with silicosis, we examined US mortality data for 1979–2004. Persons with silicosis were more likely to die with pulmonary mycosis than were those without pneumoconiosis or those with more common pneumoconioses. Health professionals should consider enhanced risk for mycosis for silica-exposed patients

A double-blind placebo-controlled clinical trial of 3 anti-tuberculosis chemoprophylaxis regimens in patients with silicosis in Hong Kong

A double-blind placebo-controlled trial of antituberculosis chemoprophylaxis was undertaken in silicotic subjects In Hong Kong where there is a high prevalence of both silicosis and tuberculosis. During 1981 to 1997, 679 Chinese men with silicosis, with no history of previous antituberculosis chemotherapy and no evidence of active tuberculosis, were admitted to the trial and have been studied for between 2 and 5 yr. They were allocated at random to four series–rifampin for 12 wk (R3), isoniazid and rifampin for 12 wk (HR3), isoniazid alone for 24 wk (H6), or placebo (PI)-in a double-blind design with matching placebos for isoniazld and rifampin as appropriate. Active pulmonary tuberculosis developed more frequently during the 5 yr in the placebo series than in the three chemoprophylaxis series (p < 0.01, log-rank test), but there were no significant differences between the chemoprophylaxis series. The estimated proportions of patients with active pulmonary disease in the placebo series were 9% at 2 yr, 15% at 3 yr, 20% at 4 yr, and 27% at 5 yr. In contrast, in the three chemoprophylaxis series combined they were 5, 8, 10, and 13% respectively. Thus, although chemoprophylaxis halved the proportion of patients in whom tuberculosis developed, this proportion was still substantial. There was no evidence that chemoprophylaxis led to the selection of drug-resistant strains of bacilli. Adverse effects were reported with a similar frequency in all four series, suggesting that few were drug related. During the first 12 wk, hepatic toxicity was reported in 8 (1%) patients (3 HR3, 3 H6, and 2 PI), but only 1 (H6) had symptomatic hepatitis. The serum alanine aminotransferase concentrations during chemoprophylaxis were higher in the HR3 and H6 series than in the R3 series (p < 0.001); there was no significant difference between the R3 and PI series. In conclusion, more effective antituberculosis chemoprophylaxis regimens for silicotic subjects are needed; rifampin on Its own probably carries a very low risk of hepatic toxicity

A controlled clinical comparison of 6 and 8 months of antituberculosis chemotherapy in the treatment of patients with silicotuberculosis in Hong kong. American Review of Respiratory Diseases

Patients with silicotuberculosis have been reported to respond poorly to antituberculosis chemotherapy. Therefore, in a study in Hong Kong, 240 Chinese male patients with both silicosis and pulmonary tuberculosis were all prescribed treatment three times weekly with streptomycin, lsoniazid, rifampln, and pyrazinamide, allocated at random to be given for a total duration of either 6 (M6 reglmen) or 6 months (M8 regimen) In a concurrent comparison. Those with a history of previous antituberculosls chemotherapy received ethambutol as well for the first 3 months. The intake in the M6 regimen was terminated when preliminary results showed that It was Inadequate, and a further 63 patients were assigned to the M8 series. Of 91 assessable patients In the concurrent comparison with susceptible strains pretreatment, 44% were culture negative at 1 month, 80% at 2 months, and 98% at 3 months, and 1 had an unfavorable bacteriologic response during chemotherapy. Durlng 3 yr of assessment, bacteriologic relapse after chemotherapy occurred in 22% of the M6 compared wlth 7% of the M8 patients (p < 0.025, log-rank test). Inadequate chemotherapy was received by 12% of the 240 patients in the concurrent comparison because of default and by 22% because of adverse effects, but by 3 yr 92% of patients with susceptible strains pretreatment in each series had a favorable status followlng retreatment for relapse or for initially inadequate chemotherapy when required. The results show that patlents with silicosis require at least 8 months of treatment

A study of the characteristics and course of sputum smear-negative pulmonary tuberculosis

A total of 302 Chinese patients were diagnosed on clinical and radiographic grounds by chest physicians from the Hong Kong Chest Service as having radiographically active pulmonary tuberculosis, but had sputum negative for acid-fast bacilli on 5 recent microscopical examinations. They were not given antituberculosis chemotherapy until active disease had been confirmed by positive bacteriological findings, or by radiographic or clinical deterioration during close observation. Of the 283 patients assessed up to 30 months, 200 (71 %) had active disease confirmed and had chemotherapy started during the 30 months. A further 42 (15 %) had evidence of changing lesions on serial chest radiography, and hence of recently active disease. A number of characteristics of the patients and of their bacteriological and radiographic status were tested singly and in combination for association with the presence of active disease confirmed on admission or at any time during the 30 months. Patients with radiographic lesions which were larger and classified as “active” on independent radiological assessment, and with a history of blood-streaked sputum or frank haemoptysis were more likely to have unquestionably active disease on admission or at some time during the 30 months, than patients without these characteristics

A Controlled Trial of 2-Month, 3-Month, and 12-Month Regimens of Chemotherapy for Sputum Smear-Negative Pulmonary Tuberculosis: The Results at 30 Months

Of 1,033 Chinese patients with radiologically active pulmonary tuberculosis but with sputum negative for acid-fast bacilli on 5 initial microscopic examinations, 370 (36%) had 1 or more initial sputum cultures that yielded tubercle bacilli. All patients were randomly allocated to (1) selective chemotherapy, antituberculosis chemotherapy not being started until active disease had been confirmed, or to (2) daily streptomycin, isoniazid, rifampin, and pyrazinamide for 2 months or (3) the same 4 drugs daily for 3 months, or to (4) a 12-month control regimen. In patients with 1 or more of their initial sputum cultures positive, the short-course regimens were inadequate, being followed by bacteriologic relapse rates of 15 and 9%, respectively, during 30 months, compared with 0% in the control series. In patients with all their initial cultures neg ative, the corresponding relapse rates were 4, 2, and 0%, and in the selective chemotherapy series, 53% of the patients had treatment started during the 30 months because active disease was confirmed (bacteriologically in 40%). It is important to continue studying short-course chemotherapy for smear. negative patients because in many countries they represent a high proportion of those treated

Sputum-smear-negative pulmonary tuberculosis: Controlled trial of 3-month and 2-month regimens of chemotherapy

Of 1072 Chinese patients with radiographically active pulmonary tuberculosis and no microscopic evidence of acid-fast bacilli in sputum examinations, only 691 (64%) were sputum-culture negative. All patients were randomly allocated to selective chemotherapy (antituberculosis chemotherapy not being started until the activity of the disease had been confirmed), to daily streptomycin, isoniazid, rifampicin, and pyrazinimide for 2 months or 3 months, or to a standard 12-month control regimen. During the subsequent 12 months, 64% of the patients in the selective chemotherapy series started antituberculosis chemotherapy. Both 2-month and 3-month regimens were inadequate for patients whose pretreatment sputum cultures were positive (relapse-rates 14% and 7%, respectively, in patients with drug-sensitive strains) but in the patients whose first cultures were negative the relapse-rate was only 1% after both short-term regimens

A controlled trial of 2-month, 3-month and 12-month regimens of chemotherapy for sputum-smear-negative pulmonary tuerculosis results at 60 months

Of 1,019 Chinese patients with radiologically active pulmonary tuberculosis but with sputum negative for acid-fast bacilli on 5 initial microscopic examinations who were studied for 5 yr, 364 (36%) had 1 or more initial sputum cultures positive for Mycobacterium tuberculosis. All 1,019 patient’s were randomly allocated to (1) selective chemotherapy (antituberculosis chemotherapy not being started until the disease had been confirmed to be active); or to (2) daily streptomycin, Isoniazid, rifampin, and pyrazinamide for 2 months; or (3) for 3 months; or to (4) a standard 12-month control regimen. In the 364 patients with 1 or more of their initial sputum cultures positive, the short-course regimens were inadequate, being followed by relapse rates of 32 and 13%, respectively, during 60 months, compared with 5% in the control series. In the 655 patients with all their initial cultures negative, the corresponding relapse rates were 11, 7, and 2%. In the selective chemotherapy series, 57% of the patients had treatment started during the 60 months because their disease was confirmed to be active

Relapse Associated with Active Disease Caused by Beijing Strain of Mycobacterium tuberculosis1

Risk for relapse was higher among persons of Asian–Pacific Islander descent