Annual risk of tuberculous infection in Taiwan, 1996-1998

Tuberculosis is still an important public health issue in Taiwan, and monitoring the trend of annual risk of infection (ARI) with Mycobacterium tuberculosis is essential. In this study, we conducted tuberculin skin tests to estimate the prevalence and annual risk of M. tuberculosis infection in first-grade schoolchildren in Taiwan Province. Because mass bacille Calmette-Guérin (BCG) vaccination programs have been carried out here, only non-BCG-vaccinated students were tested. From September 1996 through June 1998, there were 520,866 registered first-grade elementary school students in Taiwan Province. Of them, 15,147 (2.9%) were non-BCG-vaccinated, as determined by the absence of a BCG scar. All of them were tested for M. tuberculosis infection with 1 tuberculin unit (0.1 mL injection) of purified protein derivative RT23, by means of the Mantoux technique. Among the tested schoolchildren, 430 (2.8%) had a positive tuberculin reaction. Thus, the calculated ARI was 0.44%. The ARI varied in different areas of Taiwan, being highest (1.04%) in Nantou County and lowest (0.14%) in Miaoli and Tainan Counties. The ARI in aboriginal areas (1.16%) was 2.7 times that in nonaboriginal areas (0.42%). Our results indicate that the M. tuberculosis ARI is still high in Taiwan. To achieve the World Health Organization target of less than 0.1% for industrialized countries, we must intensify tuberculosis control programs in Taiwan.

Short-course chemotherapy for isoniazid-resistant pulmonary tuberculosis

Standard short-course chemotherapy including isoniazid, rifampicin, pyrazinamide, and ethambutol has been the recommended treatment for tuberculosis in Taiwan since November 1990. The effectiveness of this treatment was evaluated retrospectively in 108 patients with isolates resistant to isoniazid alone and 115 patients with drug-susceptible pulmonary tuberculosis diagnosed and treated at the Taiwan Provincial Chronic Disease Control Bureau from November 1990 through December 1995. The success rate of treatment was 94.4% in patients with isoniazid-resistant Mycobacterium tuberculosis strains, which was not significantly different from the 97.4% rate in patients with susceptible strains. Of the patients treated successfully, no bacteriologic relapse was found in 97 patients with isoniazid-resistant strains or 103 patients with drug-susceptible strains 12 months after the end of chemotherapy. No significant advantage in treatment outcome was found in patients infected with isoniazid-resistant strains who received chemotherapy for more than 6 months (successful treatment rate, 95.0% vs 92.8%), but the failure rate was higher in patients with a previous history of antituberculosis therapy (17.6% vs 3.3%). We conclude that short-course chemotherapy is effective for isoniazid-resistant pulmonary tuberculosis and that there is no significant difference in treatment outcome between patients with or without isoniazid-resistant disease.

Screening of human immunodeficiency virus infection in pulmonary tuberculosis patients in Taiwan

To disclose the impact of human immunodeficiency virus (HIV) infection on the tuberculosis epidemic in Taiwan, we prospectively screened for HIV infection in patients with active pulmonary tuberculosis. A total of 378 patients who were admitted to the Taiwan Provincial Chronic Disease Control Bureau from January through December 1996 were enrolled. HIV serologic testing was performed by enzyme-linked immunosorbent assay (ELISA). A positive ELISA test was confirmed by Western blot analysis. One patient was infected with HIV. We conclude that the impact of HIV infection on the epidemic of tuberculosis in Taiwan is not significant at present.

Initial drug resistance of Mycobacterium tuberculosis in Taiwan

The prevalence and mortality rate of pulmonary tuberculosis in adults are high in Taiwan. Because the emergence of drug-resistant tuberculosis is one of the major causes of this sustained high tuberculosis mortality, surveillance of initial drug resistance is important. We tested Mycobacterium tuberculosis isolates from 1,935 newly diagnosed tuberculosis patients from January 1990 through December 1995 at the Taiwan Provincial Chronic Disease Control Bureau. The overall initial drug resistance rate was 12.3%; 8.7% of isolates were resistant to only one drug, 2.6% to two drugs, 0.7% to three drugs, and 0.3% to four drugs. The resistance rates to individual drugs were: streptomycin, 5.7%; isoniazid, 9.2%; ethambutol, 0.7%; and rifampin, 1.5%. The frequency of multidrug-resistant M. tuberculosis (resistant to at least isoniazid and rifampin) was 1.2%. In view of the high initial isoniazid resistance rate and low initial ethambutol resistance rate, ethambutol should be added to the regimen for the initial treatment of tuberculosis in Taiwan. The emergence of multidrug-resistant M. tuberculosis is ominous and should be considered when treating patients in Taiwan.

Serodiagnosis of tuberculosis. A study comparing three specific mycobacterial antigens

To compare the efficacy of different mycobacterial specific antigens and to assess the applicability of the combination of several different antigens in the diagnosis of tuberculosis, three ELISA tests derived by Antigen 60, 38kda, and Kp90 were evaluated in 594 Chinese patients (312 patients with active pulmonary tuberculosis and 282 control subjects). Quantified levels of sensitivity and specificity were compared with those in the nontuberculous control groups. Antigen 60 IgG (sensitivity and specificity, 80.77 and 88.4%) was more antigenic and more effective in its determination than was 38kda IgG (sensitivity and specificity, 64.21 and 80.74%) and Kp90 IgA (sensitivity and specificity, 62.58 and 66.3%). The clinical significance of the difference, however, was not striking: negative predictive value of Antigen 60, 38kda, and Kp90 was 93, 86 and 83%, respectively; positive predictive value of Antigen 60, 38kda, and Kp90 was 71, 54, and 39%, respectively. Combination of different antigens could improve the sensitivity and specificity by no more than 10%, with the sacrifice of the opposite parameter by no less than 20%. The same improvement in sensitivity could be easily achieved by adjusting the cutoff values in the ELISA test by a single antigen. We conclude that the sensitivity and specificity of presently available antigens for serodiagnosis of tuberculosis still remains limited at around 80%, which makes it a poor diagnostic tool for disease confirmation. In low incidence areas, its clinical value may be useful in disease exclusion. A combination of several different antigens provides no more improved diagnostic yield than what can be provided by cutoff value adjustment in a single antigen serologic test.

[Study of dermatomycosis and survey of pathogens in troops of Hainan area]

Subtropical area is the prevalent area of dermatomycosis with natural conditions suptable for the growth and proliferation of fungi causing suterficial dermatomycosis. Dermatomycosis not only brings about certain sufferings to the military personnel in peacetime, but also causes nonbattle loss in manpower in war time. In the present work, a survey of dermatomycosis in Hainan subtropical area of China and isolation of the pathogens were carried out. The results were as follows: The morbidity of superficial dermatomycosis was 34.1% and it was manifested clinically as tinea pedis, tinea versicolor, tinea corporis, tinea axillaris, tinea cruris, etc.; The main pathogen causing dermatomycosis in this area was Trichophyton rubrum which accounted for 50.4% of the pathogens isolated and the next was Trichophyton gypseum which accounted for 20.3%; Trichophyton rubrum could cause dermatomycosis of many sites of the body in this area, but the main lesious were tinea corporis and tinea cruris.

[Study of the relationship between the control of environmental microorganism and infection of patients with leukemia after trasplantation of bone marrow]

After the transplantation of bone marrow, patients with leukemia are easily infected by kinds of microorganism and die. In this paper, F-mice with the 60Co-gamma irradiation (maximum lethal dose) were transplanted bone marrow, then control the microorganism in the environment. Morever the laminar flow wards for the leukemia patient of bone marrow transplantation were designed according to the data combined with the clinic condition. There is no any infection in twelve patients with bone marrow transplantation from 1989 to 1993.

In vitro activity of ofloxacin against Mycobacterium tuberculosis

For the past 3 years, ofloxacin has been widely used in treating patients with drug-resistant tuberculosis in Taiwan. To study its usefulness in treating these patients, 139 isolates of Mycobacterium tuberculosis from patients treated at the Taiwan Provincial Chronic Disease Control Bureau from September 1994 to September 1995 were tested to determine the in vitro antituberculosis activity of ofloxacin. Of these, 131 had not been previously exposed to ofloxacin, and 130 (99.2%) were susceptible to ofloxacin. Sixty-four isolates were found to be susceptible to all conventional antituberculosis drugs, and all of these were also susceptible to ofloxacin. Of the remaining 67 isolates that were resistant to one or more conventional antituberculosis drugs, 66 (98.5%) were susceptible to ofloxacin. There was no association between susceptibility to ofloxacin and susceptibility to conventional antituberculosis drugs among the isolates tested. Of the eight isolates of M. tuberculosis previously exposed to ofloxacin, seven (87.5%) were resistant. Our results indicate that patients with multidrug-resistant strains of M. tuberculosis who have not received prior ofloxacin treatment may be safely treated with ofloxacin even without knowing the result of pretreatment ofloxacin susceptibility tests. We also found that ofloxacin resistance emerges frequently. Therefore, an adequate combination of antituberculosis drugs, along with ofloxacin, should be prescribed to prevent the development of resistance to ofloxacin.

[Study of relationship between the bacteria in air and the clinic infection]

The Source of infectious bacteria is the first problem in provension of infection considered by the medical workers. In this paper, with the method of bacteria plasmid analysis, chromosome DNA restriction fragment length polymorphism analysis, drug resistance experiment (antibacterial drug, sterilizing drug) and so on. We confirmed that staphylococci of nosocomi is mainly from air; but the gram-negative bacteria is mainly from the patient's pharyngeal portion; and cause hospital infection indirectly. The drug resistance of gram-negative from air was lower than the same gram-negative bacilli's isolated from the patient. Moreover, kill bacteria the infectious strain is same strain in air. Above-mentioed results provided the important basis for control of the hoslpital infection.

Treatment of multidrug-resistant tuberculosis in Taiwan

Eighty-seven patients with multidrug-resistant tuberculosis (MDR-TB) diagnosed between 1988 and 1990 were treated with isoniazid and at least three other effective second-line drugs based on in vitro susceptibility tests. Of these patients, 10% failed to adhere to the regimen and 43% remained sputum positive after 6 months of treatment. Only 47% showed sputum conversion within 6 months of treatment and 12% of them relapsed during the first year of follow-up. From September 1987 to July 1989, 36 patients with MDR-TB were treated with a regimen containing rifabutin, isoniazid and at least three other susceptible drugs. Only 47% achieved a sustained sputum conversion. Four died during treatment due to disease progression. From March 1992 to July 1993, 17 cases of MDR-TB were treated with an ofloxacin-containing anti-TB regimen for 12-24 months. Two failed to adhere to the regimen for more than 1 month during the first 6 months of therapy. Among the remaining 15, 26% failed to achieve sputum conversion, 73% achieved bacterial conversion, 9 within 1 month and the other 2 within 2 months. No significant adverse effect was associated with ofloxacin use. We concluded that ofloxacin is a better choice among the more toxic and less potent second-line drugs, and should be used along with other anti-TB drugs in treating patients with MDR-TB.

Percutaneous endovascular embolization of intracerebral arteriovenous malformations. Experience in 72 cases

Endovascular therapeutic embolization of arteriovenous malformations (AVMs) of the brain was performed in 72 patients between October 1986 and March 1993. From October 1986 to May 1991, 38 patients in this series were treated with isobuty1-2-cyanoacrylate (IBCA) glue. After June 1991, in the remaining 34 patients the embolic materials used included surgical silk (5-0), polyvinyl alcohol (PVA), ethanol, and estrogen. After treatment, 29 patients (40.3%) had complete angiographic obliteration of AVM, 15 (21%) transient neurologic postembolization deficit, and 3 (4%) permanent deficit without death. Embolic agents and procedures are discussed as to their curative effects, safety, normal perfusion pressure breakthrough (NPPB) problem, with silk mixture fluid being considered preferable.

[High yield techniques for bupleurum falcatum L]

The growth of plants may be controlled by clipping the aerial part. This may increase the yield of Bupleurum falcatum. Different methods of cultivation may result in different outputs of crude drugs. Compared with land plotting, deep ploughing and high ridging may increase the root weight of one-year-old plant by 28% and 50% respectively.

Suppression of hepatic natural killer activity by liver metastasis of cancer and restoration of killer activity by oral administration of a Basidomycetes-derived polysaccharide, PSK

PSK (Krestin) is a protein-bound polysaccharide with antitumor and immunomodulatory activity. In this study, the effects of the oral administration of PSK were investigated on the natural killer (NK) activity of liver-associated lymphocytes and their subfractions separated by density gradient centrifugation, in WKAH rats with liver metastasis of KDA hepatoma. PSK was administered orally, at a dose of 500 mg/kg once a day for 3 weeks. The NK activity of nonparenchymal liver cells (NPLC) and their subfractions, including large granular lymphocytes (LGL), was markedly augmented by this treatment. The effects of oral PSK were also examined in CDF1 mice with liver metastases of Colon 26 adenocarcinoma; the survival of tumor-bearing mice was prolonged and both metastatic foci and liver weight were decreased. These results suggest that PSK may be effective for the suppression of liver metastasis through activation of liver-associated NK cells.

Quantitative measurement of drug susceptibility of Mycobacterium tuberculosis for monitoring chemotherapy response

Changes in the degree of drug susceptibility of the bacterial population in tuberculosis patients during chemotherapy can be monitored by testing Mycobacterium tuberculosis isolates against various concentrations of drugs in 7H12 broth to determine radiometrically the minimal inhibitory concentration (MIC). The MICs were determined for multiple cultures isolated from 13 patients, of whom nine responded to chemotherapy within a few months, and four failed to respond at all. No changes in MICs were observed with the isolates obtained from the patients with a favorable response to chemotherapy. Determination of the MICs indicated that the failure in two cases out of four was associated with a steady increase in the degree of resistance of the patients' bacterial population. In two other failure cases, lack of change in the MIC values for multiple cultures suggests that the failure was associated with factors other than drug resistance. During the period of chemotherapy, quantitation of the degree of drug susceptibility in terms of broth-determined MICs may help to identify promptly those patients whose bacterial population is becoming resistant to the administered antimicrobial agents. For those patients who do not respond to chemotherapy, lack of change in the degree of resistance of their bacterial population may alert the physician to attempt to identify causes other than drug resistance for the chemotherapy failure.

Family factors affecting the outcome of tuberculosis treatment in Taiwan

Despite the progress of tuberculosis (TB) control, the failure of treatment mainly due to non-adherence to medical recommendations remains a major obstacle to the eradication of this disease in both industrialized and developing countries. We interviewed 397 active pulmonary TB cases (274 males and 123 females) in Taiwan and followed up their treatment outcomes. No significant differences were found between any of the groups of either sex on TB cognition scores. Positive correlations between cognition scores and compliance scores, between cognition scores and family apgar scores, and between compliance scores and family apgar scores were noted in this study. In males, the complete treatment group had a higher compliance score (mean +/- standard deviation = 13.45 +/- 2.80) and family apgar score (22.44 +/- 2.29) than the incomplete treatment group (11.61 +/- 3.21 and 14.77 +/- 3.92, respectively). In females, the complete treatment group had a higher cognition score (65.99 +/- 6.75), compliance score (13.65 +/- 2.55) and family Apgar score (22.78 +/- 2.30) than the incomplete treatment group (62.05 +/- 6.91, 11.70 +/- 3.04 and 14.84 +/- 3.80, respectively). In the logistic regression analysis, both the family Apgar score and compliance score were significantly related to the TB treatment outcomes. The subjects with a family Apgar score higher than 20 had a chance to complete treatment as high as 72-fold (95% confidence interval = 31.7-164.0) that of those with a score less than 20.(ABSTRACT TRUNCATED AT 250 WORDS)

Occupational exposure and respiratory morbidity among asbestos workers in Taiwan

To determine the prevalence of asbestos-related lung disease and the impairment of lung function among asbestos workers, we conducted a cross-sectional health survey of 459 workers in 33 asbestos-related factories in Taiwan. Each worker was asked about his medical and occupational history and was given a medical examination, chest roentgenogram and pulmonary function test. Manufacturing processes included production of asbestos cements, textiles, friction materials and insulation products. Exposure assessments were based on asbestos sampling and counting using a phase contrast microscope. The average age of the participants in the study was 41.6 years. They had an average of 8.1 years of dust exposure, with a range of one to 42 years. The majority had a cumulative asbestos exposure of less than 20 fiber years/mL. No case of asbestos-related lung disease was found during our investigation. No roentgenogram showed unequivocal changes of asbestosis. However, a multiple linear regression analysis of the pulmonary function test showed that both FVC and FEV1 decreased significantly with an increasing cumulative dose of exposure after controlling for age, height and smoking effects during analysis. FEV1/FVC and FEF25-75% were not affected by exposure dose. The absence of asbestosis and other asbestos-related lung diseases may be due to an inadequate induction time of asbestos exposure and a possible healthy selection of workers. We conclude that among workers in Taiwan, there is a significant effect on the respiratory system, especially pulmonary function, due to asbestos exposure.

Morbidity and mortality trends of pulmonary tuberculosis in Taiwan

An epidemiologic study of pulmonary tuberculosis was carried out to examine the secular trend and geographic variations of the incidence, prevalence and mortality of pulmonary tuberculosis in Taiwan. The prevalence and incidence rates declined-steadily from 1910 to 1980, but have remained unchanged during the last decade. Mortality also showed an 8.0% annual decrease from 1974 to 1986, but has remained constant without any apparent changes in recent years. Mortality for pulmonary tuberculosis is much higher in the aboriginal areas, where patients have a poor adherence to treatment and where a high prevalence of alcohol abuse exists. The mortality for pulmonary tuberculosis in Taiwan is higher than that in most developed countries, such as the U.K. and the U.S.A., but is lower than that in mainland China and the Republic of Korea.

The effect of hyperinflation on respiratory muscle strength and efficiency in healthy subjects and patients with asthma

We evaluated respiratory muscle strength and efficiency in 15 patients with asthma. There was a significant reduction in mean Plmax (89.3 +/- 4.7 versus 110.5 +/- 9.4 cm H2O, p less than 0.001) and efficiency (2.41 +/- 0.2 versus 4.2 +/- 0.6%, p less than 0.01). This reduction in strength and efficiency was seen only in the male patients. Following bronchodilator, there was a significant increase in Plmax (from 89.3 +/- 4.7 to 96.2 +/- 5.4 cm H2O, p less than 0.005) and efficiency (from 2.41 +/- 0.2 to 3.22 +/- 0.2%, p less than 0.001). There was no correlation between the change in strength and efficiency and the degree of improvement in FEV1 following bronchodilator. However, there was a significant correlation with the fall in lung volume. To determine whether hyperinflation would result in a reduction in respiratory muscle strength and efficiency, we induced a mean increase in end-expiratory lung volume of 0.66 L by applying continuous negative pressure around the chest in 10 healthy individuals. This was associated with a significant fall in Plmax (from 110.5 +/- 9.4 to 100.5 +/- 8.93 cm H2O, p less than 0.001) and efficiency (from 4.2 +/- 0.6 to 2.6 +/- 0.5%, p less than 0.005). The data suggest that the strength and efficiency of the respiratory muscles are reduced in asthmatic males but not in the females. The strength and efficiency of the respiratory muscles improve significantly following bronchodilator, and this improvement is related to reduction in lung volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficiency of the respiratory muscles in healthy individuals

We evaluated respiratory muscle performance by determining the energy cost of breathing against incremental threshold loads and calculating the efficiency of the respiratory apparatus for handling the added work. In five subjects, the energy cost of breathing against the loads, and thus the calculated efficiency of the respiratory muscles, was reproducible on repeated measurements. In all subjects, the calculated efficiency varied while breathing with low loads but was relatively constant at loads that resulted in a mouth pressure of 20 to 60% of the subjects' maximal static inspiratory pressure (PImax). The mean efficiency calculated between 20 to 60% of PImax in 30 normal subjects (15 males and 15 females) ranged between 1.54 and 7.98%. It was significantly greater in males (5.41 +/- 0.43%) (mean +/- SEM) than in females (2.41 +/- 0.17%). There was no relationship between efficiency and body size, but the efficiency correlated with inspiratory muscle strength (PImax). We suggest that measurement of the efficiency of the respiratory muscles over a spectrum of incremental threshold loads is a simple, noninvasive, and reproducible method of assessing respiratory muscle performance and may have clinical application.

Minimal inhibitory concentrations of isoniazid, rifampin, ethambutol, and streptomycin against Mycobacterium tuberculosis strains isolated before treatment of patients in Taiwan

Minimal inhibitory concentrations (MICs) of isoniazid (INH), rifampin (RMP), ethambutol (EMB), and streptomycin (SM) for susceptible "wild" M. tuberculosis strains isolated from Taiwanese patients were within the limits previously reported for strains isolated in the United States. The highest agar-determined MICs (in 7H10 and 7H11 agar) corresponded well with the critical concentrations established for these media. The highest MICs found radiometrically in 7H12 broth were significantly lower than the critical concentrations proposed for this medium. On the basis of an evaluation of the highest broth-determined MICs found in this and in the previous study (1), we suggest that the following MICs, when determined radiometrically, should be used as breakpoints to classify the strain as "susceptible": for INH, 0.1 microgram/ml or less; for RMP, 0.5 microgram/ml or less; for EMB, 4.0 micrograms/ml or less; for SM, 2.0 micrograms/ml or less.

Short-course chemotherapy of pulmonary tuberculosis in pneumoconiotic patients

This is the first prospective clinical trial recorded to date of short-course chemotherapy in pulmonary tuberculosis complicated by pneumoconiosis. Forty-eight anthrasillicotic and 11 silicotic patients with previously untreated pulmonary tuberculosis completed 9-month, short-course chemotherapy regimens: 2 months of daily streptomycin, isoniazid, rifampicin, and pyrazinamide followed by daily isoniazid and rifampicin for 7 months (2SHRZ/7HR). There were 3 treatment failures (5%). The remaining 56 patients (95%) all had their sputum converted within 4 months (mean, 1.5 months). Bacteriologic relapses were noted in 3 patients (5%) after 18 to 40 months of follow-up (mean, 28.4 months). The relapses occurred within 7 months after chemotherapy was stopped. There were 2 deaths from nontuberculosis causes during the follow-up period. Fifty-one patients (90%) remained bacteriologically sterile for 28.4 +/- 6.1 months. These results suggest that the 2SHRZ/7HR regimen is satisfactory in treating anthrasilicotic or silicotic patients with pulmonary tuberculosis, though antituberculosis chemotherapy seemed less effective in patients with pneumoconiosis than in those without pneumoconiosis.