Improved consistency in dosing anti-tuberculosis drugs in Taipei, Taiwan.

BACKGROUND: It was reported that 35.5% of tuberculosis (TB) cases reported in 2003 in Taipei City had no recorded pre-treatment body weight and that among those who had, inconsistent dosing of anti-TB drugs was frequent. Taiwan Centers for Disease Control (CDC) have taken actions to strengthen dosing of anti-TB drugs among general practitioners. Prescribing practices of anti-TB drugs in Taipei City in 2007-2010 were investigated to assess whether interventions on dosing were effective. METHODOLOGY/PRINCIPAL FINDINGS: Lists of all notified culture positive TB cases in 2007-2010 were obtained from National TB Registry at Taiwan CDC. A medical audit of TB case management files was performed to collect pretreatment body weight and regimens prescribed at commencement of treatment. Dosages prescribed were compared with dosages recommended. The proportion of patients with recorded pre-treatment body weight was 64.5% in 2003, which increased to 96.5% in 2007-2010 (p<0.001). The proportion of patients treated with consistent dosing of a 3-drug fixed-dose combination (FDC) increased from 73.9% in 2003 to 87.7% in 2007-2010 (p<0.001), and that for 2-drug FDC from 76.0% to 86.1% (p = 0.024), for rifampicin (RMP) from 62.8% to 85.5% (p<0.001), and for isoniazid from 87.8% to 95.3% (p<0.001). In 2007-2010, among 2917 patients treated with either FDCs or RMP in single-drug preparation, the dosage of RMP was adequate (8-12 mg/kg) in 2571(88.1%) patients, too high in 282(9.7%), too low in 64(2.2%). In multinomial logistic regression models, factors significantly associated with adequate dosage of RMP were body weight and preparations of RMP. Patients weighting <40 kg (relative risk ratio (rrr) 6010.5, 95% CI 781.1-46249.7) and patients weighting 40-49 kg (rrr 1495.3, 95% CI 200.6-11144.6) were more likely to receive higher-than-recommended dose of RMP. CONCLUSIONS/SIGNIFICANCE: Prescribing practice in the treatment of TB in Taipei City has remarkably improved after health authorities implemented a series of interventions.

Is it appropriate to routinely use a nucleic acid amplification test for the diagnosis of tuberculosis?

The purpose of this study was to compare the usefulness of the nucleic acid amplification (NAA) test against conventional tests under normal laboratory operational conditions. The NAA test was performed on the first sputum specimen of all patients. Liquid media culture, solid media culture, and Ziehl-Neelsen stain for an acid-fast bacilli (AFB) smear were performed on three sputum specimens. The results were calculated using the gold standard of either the culture results or the clinical diagnosis. Of the 593 patients tested, 151 (25.5%) were diagnosed with pulmonary tuberculosis. The sensitivity of the first specimen only was 64% for the NAA test, 54% for the AFB smear, 77% for BACTEC MGIT 960 culture, 40% for Lowestain-Jensen (LJ) culture, and 25% for 7H11 culture. The sensitivity when using all three specimens increased to 63% for AFB smear, 87% for BACTEC MGIT 960 culture, 51% for LJ culture, and 40% for 7H11 culture. The specificity was 100% for all culture tests, 99% for the AFB smear, and 99.5% for NAA test. The mean turnaround time was 1.34 days for NAA, 0.59 days for AFB smear, 11 days for BACTEC MGIT 960 culture, 23 days for LJ culture, and 20 days for 7H11 culture. We conclude that the sensitivity of NAA is still far from ideal, and the test is not cost effective. Thus, the COBAS AMPLICOR PCR system is not suitable for routine use in microbiology laboratories.

Antituberculosis drug resistance among retreatment tuberculosis patients in a referral center in Taipei.

BACKGROUND AND PURPOSE: To determine the prevalence of antituberculosis drug resistance among retreatment tuberculosis patients in a referral center in Taipei. METHODS: We reviewed the register of susceptibility testing of the mycobacteriology laboratory of the Chronic Disease Control Bureau to identify patients with positive culture for Mycobacterium tuberculosis in the year 2000-2001. Medical charts were reviewed to determine patients' tuberculosis treatment histories. Patients who had multidrug-resistant (MDR) tuberculosis, defined as documentation of isolates resistant to at least isoniazid and rifampin, were identified. Retreatment tuberculosis patients without prior evidence of MDR tuberculosis were classified into 3 categories, i.e., relapse, treatment after default and treatment after failure, and the frequency and patterns of antituberculosis drug resistance were determined. RESULTS: A total of 317 patients who had received antituberculosis treatment for more than 1 month were identified. Among them, 183 were retreatment cases without prior evidence of MDR tuberculosis, including 93 with relapse, 57 with treatment after default, and 33 with treatment after failure. Among the 183 patients, the prevalence of resistance to any drug was 42.6%; 14.2% were resistant to 1 drug, 13.7% to 2 drugs, 7.1% to 3 drugs, 7.7% to 4 drugs or more, and 24.6% had MDR tuberculosis. The prevalence of any drug resistance among patients with relapse, treatment after default and treatment after failure was 33.3%, 42.1%, and 69.7%, respectively, while the prevalence of MDR tuberculosis in these groups was 12.9%, 19.3% and 66.7%, respectively. CONCLUSIONS: If susceptibility results are unavailable, the World Health Organization-recommended retreatment regimen may be used in retreatment tuberculosis patients. However, the high proportion of MDR tuberculosis among patients with treatment after failure poses a challenge to the efficacy of the retreatment regimen.

Pulmonary tuberculosis in the Taiwanese prison population.

BACKGROUND AND PURPOSE: Tuberculosis (TB) in prison is a serious public health problem that is fueled by overcrowding, poor nutrition and unsatisfactory medical services. To evaluate the magnitude of the TB epidemic in Taiwanese prisons, we analyzed the results of a screening program for TB among inmates. METHODS: A mass radiography screening was performed in 24 prisons and five jails from July 1998 through June 1999. The National TB Register was notified and treatment with a rifampin-based short-course anti-TB regimen was given for all cases identified in the screening. The outcome of treatment of TB inmates was determined from records of the National TB Register. RESULTS: A total of 51,496 inmates were screened. Pulmonary TB was diagnosed in 107 (258.7 per 100,000 population) inmates. Among them, 88 (82.2%) were newly diagnosed TB patients, 12 (11.2%) had a history of anti-TB treatment and were re-treated after screening, and seven (6.6%) had previously diagnosed TB and were receiving treatment at the time of screening. Of the 107 inmates with TB, 86 (80.4%) completed treatment, 17 (15.9%) were lost to follow-up due to release from prison, and four (3.7%) died (three of TB). During a mean of 26.2 +/- 4.4 months (range, 19.7-39.0 mo) post-registration follow-up, three patients who had completed treatment relapsed. CONCLUSIONS: The high prevalence of TB in prisons indicates that prison administrators and the national TB program in Taiwan need to strengthen their activity to control this disease. The establishment of a surveillance section of the national TB program to systematically collect data on TB in prisons may facilitate efforts to monitor and control TB both in prisons and the general population. Our findings also indicate that TB control in prisons should give top priority to improving mycobacteriology laboratory services to ensure the quality of sputum examinations.

rpoB genotypes of Mycobacterium tuberculosis Beijing family isolates from East Asian countries.

The 81-bp region of the rpoB gene in 66 Rif(r) Mycobacterium tuberculosis isolates from China, Japan, Korea, and Taiwan was analyzed. Twelve single-nucleotide substitutions in the rpoB gene were detected. The most prevalent mutations were at Ser-531 (52%), Asp-516 (17%), and His-526 (11%). Mutations were not found in seven (11%) of the isolates. Higher mutation rates in 50 Beijing family isolates were found than in other isolates for mutations at Asp-516 (18 and 12.5%, respectively) and His-526 (12 and 6.3%, respectively). The different rates of mutation may reflect the choice of rifamycin analogs.

Screening for pulmonary tuberculosis among military conscripts in Taiwan.

BACKGROUND AND PURPOSE: Military service is obligatory for young men who are medically fit in Taiwan. Each year, all 19-year-old men are notified to undergo a required health check to determine their eligibility for military service. This study determined the prevalence of pulmonary tuberculosis (TB) among military conscripts in 1997 and 1998 and evaluated the effect of the mass radiographic screening program for military conscripts on the reported TB case rate. METHODS: During the annual health check, all 19-year-old men in Taiwan undergo miniature (70 x 70 mm) chest roentgenography (CXR). Those who have suspicious lesions on miniature films are notified to undergo follow-up CXR (14 x 14 inch) and sputum examinations. All these data for the period from 1997 to 1998 were analyzed to determine the prevalence of pulmonary TB. To evaluate the effect of the mass radiographic screening program among military conscripts on the reported TB case rates, annual data for newly diagnosed pulmonary TB in 1997 and 1998 were obtained from the National TB Register and analyzed by age and sex. RESULTS: A total of 305, 140 men eligible for military service underwent the required examination in 1997 and 1998. Pulmonary TB was diagnosed in 237 (0.08%) of these men, and 21 (6.9/100,000) had positive bacteriologic findings. In 1997 and 1998, the annual reported TB case rates for males and females were similar in both children and young adults, except for an early peak among men aged 19 years. CONCLUSION: The screening program resulted in a significant increase in the reported TB case rate among males aged 19 years. However, a low bacteriologic confirmation rate implies the possibility of over-diagnosis with CXR. Mass radiographic screening at the health check for military conscripts is inefficient in detecting bacteriologically confirmed TB, an observation with implications for screening policy development by the national TB program.