34 research outputs found
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
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
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
Relapse Associated with Active Disease Caused by Beijing Strain of Mycobacterium tuberculosis1
Risk for relapse was higher among persons of Asian–Pacific Islander descent