TB-related technical enquiries received in Japan, 2017-2019

SETTING

Japan, an intermediate TB burden country.

OBJECTIVE

To review TB-related technical enquiries received at the Research Institute of Tuberculosis, Japan, from January 2017 to December 2019.

DESIGN

This was a cohort study.

RESULTS

A total of 2,197 enquiries were analysed. On average, 61.0 enquiries/month (range: 42-81) were received. The enquiry rates were highest for the Yamanashi (4.65/100,000 population) and Ishikawa (4.55) Prefectures, and lowest in the Yamagata (0.46) and Tochigi (0.56) Prefectures. The main organisations the enquirers belonged to were local governments (n = 1,585, 72.1%) and healthcare facilities (n = 307, 14.0%). The enquirers were medical doctors (n = 391, 17.8%), nurses (n = 1,207, 54.9%), other healthcare professionals (n = 57, 2.6%), the general public (n = 168, 7.6%) and others/unknown (n = 374, 17.0%). The most frequent enquiries were about TB diagnosis and treatment (n = 501, 22.8%), including laboratory diagnosis (n = 88, 4.0%), TB treatment in general (n = 93, 4.2%) and management of comorbidities (n = 86, 3.9%), followed by contact investigations (n = 385, 17.5%) and TB in foreigners (n = 344, 15.7%).

CONCLUSION

As the most frequent enquiries were about diagnosis and treatment of TB, the health ministry of Japan should maintain a few specialised TB institutions with TB physicians to provide technical assistance.

Characteristics of migrants to Japan with TB and implications for pre-migration TB screening

Background

Japan plans to introduce pre-entry tuberculosis (TB) screening for those traveling from the Philippines, China, Vietnam, Nepal, Indonesia, and Myanmar, who are intending to stay in Japan for more than 90 days, in 2020. According to its screening algorithm, migrants will be screened by chest X-ray and those with abnormal findings will be asked to undergo sputum testing. We analyzed the characteristics of foreign-born TB patients coming from the above six countries, to identify some potential issues.

Methods

Data on foreign-born patients who had been newly notified with active pulmonary TB (PTB) in 2018 and 2017, and who had entered Japan in the same year they were notified, was extracted from the Japan TB Surveillance system. We assumed that these patients approximated to those hypothetical migrants who would be detected by pre-entry TB screening, and analyzed them by basic socio-demographic characteristics, radiological findings, and bacteriological test results.

Results

In 2017 and 2018, a total of 1,915 foreign-born PTB patients were notified from the above six countries. Of them, 19.9% (n = 381) had entered Japan in the same year they were notified. Among the 381, 23.9% (n = 50) had cavitary lesion, 27.3% (n = 57) were smear positive, and 48.9% (n = 73) were culture positive. 34.4% (n = 72) were both smear and culture negative, and the diagnosis would have depended on radiographical presentation. However, among the 72, the majority i.e. 87.5%, presented with non-cavitary pulmonary involvement.

Conclusions

Considering that approximately a third of TB patients who would may detected by the pre-entry screening are likely to be bacteriologically negative, Japan must ensure that the clinics conducting the pre-entry TB screening have access to high-quality radiography with expert interpretations, such as teleradiology and computer-assisted reading.

Key messages

A third of TB patients who would may detected by the pre-entry screening are likely to be bacteriologically negative. It is critical that clinics conducting screening have access to high-quality radiography with expert interpretations, such as teleradiology and computer-assisted reading.

Western Pacific Regional Green Light Committee: progress and way forward

•

The Western Pacific Regional Green Light Committee (rGLC WPR) was established in 2011 to promote scale-up of programmatic management of drug-resistant tuberculosis (PMDT).

•

rGLC WPR has generated greater awareness of regional challenges and has encouraged local solutions to regional problems.

•

PMDT should be part and parcel of routine TB programme activity.

•

Challenges and bottlenecks have varied according to the different stages of PMDT implementation, requiring different types of technical assistance.

•

Regional initiatives should be dynamic and responsive to the needs of countries.

The Western Pacific Regional Green Light Committee (rGLC WPR) was established in 2011 to promote the rational scale-up of programmatic management of drug-resistant tuberculosis (PMDT). We reflect on its achievements, consider the challenges faced, and explore its potential future role. Achievements include the supervision and support of national PMDT action plans, increased local ownership, contextualized guidance, and a strong focus on regional capacity building, as well as a greater awareness of regional challenges. Future rGLC activities should include (1) advocacy for high-level political commitment; (2) monitoring, evaluation, and supervision; (3) technical support and contextualized guidance; and (4) training, capacity building, and operational research. Regional activities require close collaboration with both national and global efforts, and should be an important component of the new Global Drug-resistant TB Initiative.

Permanent employment or public assistance may increase tuberculosis survival among working-age patients in Japan

OBJECTIVES

To measure the effect of employment and health insurance status on the survival of working age tuberculosis (TB) patients in Japan.

METHODS

Retrospective cohort analysis of new smear-positive pulmonary TB patients aged 15-59 years registered in the Japanese national TB surveillance system between 2007 and 2010. We performed univariate and multivariate Cox proportional hazard model analysis. The survival curves for employment and health insurance status were calculated using Kaplan-Meier analysis.

RESULTS

Of 9097 patients studied, 267 (2.9%) died of TB within 12 months. After adjustment with a multivariate model, employment and health insurance status were independently associated with increased risk of TB death: unemployment (HR 2.80, 95%CI 2.11-3.72), absence of insurance (HR 1.48, 95%CI 1.02-2.15). The analysis of survival curves indicated that those with public assistance had almost the same survival rate as insured patients in the unemployed group. Permanent workers (employed >30 days) had the highest survival rates, followed by casual workers (employed <30 days) and the unemployed in the insured group.

CONCLUSION

Patients with permanent jobs had better survival rates than unemployed patients and casual workers. Despite being unemployed, receiving public assistance could improve survival. Health measures are required for the unemployed and casual workers.

Development and validation of a tuberculosis prognostic score for smear-positive in-patients in Japan

BACKGROUND

No scoring system has ever been used to estimate the prognosis of individual tuberculosis (TB) patients.

OBJECTIVE

To develop and validate a tuberculosis prognostic score.

METHODS

This retrospective cohort study conducted in Japan comprised the development (n = 179; mean age 65.9 ± 18.8 years) and validation (n = 244; mean age 64.3 ± 20.1 years) of a tuberculosis prognostic score among patients with newly diagnosed smear-positive non-multidrug-resistant pulmonary tuberculosis without human immunodeficiency virus infection. The score (raw score) was defined by modifying a logistic regression formula using known risk factors as independent variables and in-patient death as a dependent variable.

RESULTS

The raw score was calculated as follows: age (years) + (oxygen requirement, 10 points) - 20 × albumin (g/dl) + (activity of daily living: independent, 0 point; semi-dependent, 5 points; totally dependent, 10 points). The raw scores were grouped into risk groups 1 (raw score < -30) to 5 (raw score ≥ 60) using 30-point intervals. Every increase in risk group was equivalent to a 7.3-fold increase in the odds ratio for in-hospital death (P < 0.001). The area under the receiver operating characteristics curve by risk group for in-patient death was 0.875 (P < 0.001).

CONCLUSIONS

In this study we were able to develop and validate a tuberculosis prognostic score.

Epidemiological impact of mass tuberculosis screening: a 2-year follow-up after a national prevalence survey

OBJECTIVE

To assess the epidemiological impact of mass tuberculosis (TB) screening in the community and the prognosis of bacteriologically negative individuals with abnormal findings on chest radiography (CXR).

METHODS

A follow-up study consisting of two parts--a register match of notified TB cases with 22,160 participants in a national TB prevalence survey, and a repeat medical examination for the subjects of a prevalence survey with abnormal findings on CXR--was conducted 2 years after the prevalence survey in Cambodia.

RESULTS

Thirty-four cases with new smear-positive TB were detected by register match, giving a standardised notification ratio of 0.38 (95%CI 0.27-0.52). An additional seven new smear-positive TB cases and 93 new smear-negative, culture-positive TB cases were detected by medical examination. The incidence rates of bacteriologically positive TB were 8.5% per year (95%CI 6.3-11.2) in cases with a CXR suggestive of active TB and 2.9% per year (95%CI 2.2-3.7) in those with a CXR with other abnormalities.

CONCLUSIONS

Detection and treatment of smear-negative, culture-positive TB cases as well as smear-positive TB cases was associated with a rapid reduction in subsequent incidence of new smear-positive TB. Sputum culture-negative individuals with abnormal CXR findings are at a high risk of disease progression, and require follow-up and potentially preventive treatment.

Abstract P3-06-26: Serum anti-p53 antibody titers predict pathological response to preoperative chemotherapy in women with HER2 positive or triple negative breast cancer

Background: In SABCS 2009, we reported that the high level of serum anti-p53 antibody titers was associated with response to preoperative chemotherapy in cases with primary breast cancer (SABCS 2009). Prognostic meaning of pathological complete response (pCR) after preoperative chemotherapy differs among various subtype, and there is a close relationship between pCR and prognosis in cases with HER2 positive or triple negative disease. The aim of this study is to evaluate the association between the high level of serum anti-p53 antibody titers and pCR in patients with HER2-positive or triple negative breast cancer.

Patients and Methods: In this study, we analyzed 196 women with operable early stage breast cancer (T1-T3, N0-1) treated with preoperative chemotherapy and definitive curative surgery since 2002 to 2011. All of the patients received four cycles of FEC (fluorouracil 500 mg/m2, epirubicin 100 mg/m2, cyclophosphamide 500 mg/m2 q3w) followed by four cycles of docetaxel (75 mg/m2 q3w). The serum anti-p53 antibody titers were assessed by ELISA with the anti-p53 EIA Kit II (MESACUP anti-53 Test: MBL) in the pre-treatment serum samples. The test's cut-off value was determined to be 1.3 IU/ml based on reference distribution in healthy control individuals. The association between serum anti-p53 antibody titers and pCR was analyzed.

Results: The subtype of tumors of 196 patients were classified to 86 of ER+/HER2−, 24 of ER+/HER2+, 29 of ER−/HER2+ and 57 of ER−/HER2−. The pCR was achieved 49 of 196 patients (25%). The pCR rate were 7%(6/86), 33%(8/24), 48%(14/29) and 37%(21/57) in the subtype of ER+/HER2−, ER+/HER2+, ER−/HER2+ and ER−/HER2− respectively. The range of serum anti-p53 antibody titers in the serum samples of 196 patients was between 0.40 and 5610 (the median was 0.40 and the average was 85.2). Excluding 86 cases with ER+/HER2−, relationship between serum anti-p53 antibody titers and pCR was evaluated. According to serum anti-p53 antibody titers with the patients of pCR, cut-off value of serum anti-p53 antibody titers was set to be 6 IU/ml. The pCR was observed in nine of 12 cases (75%) with high serum anti-p53 antibody titers, which was significantly higher than those with low titers (35%: 34/98; p = 0.01). Multivariate analysis showed that the only high anti-p53 antibody titer was an independent predictive factor for pCR due to preoperative chemotherapy (p = 0.01).

Conclusion: p53 mutation analysis using serum anti-p53 antibody titers might be a useful predictive test for response to preoperative chemotherapy in patients especially with HER2 positive or triple negative breast cancer.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-06-26.

P5-13-21: Japanese Patients with Discordance in Estrogen Receptor between Primary Breast Cancer and Recurrent Tumor Have a Poorer Outcome

Background Decisions of systemic treatment for recurrent breast cancer are usually based on the estrogen receptor (ER), progesterone receptor (PR), and HER2 receptor status of the primary tumor. Recently, discordance in receptor status between primary and recurrent tumors has been reported. The objective of this study was to compare receptor status between the primary and recurrent tumor, and to evaluate overall survival (OS) after the diagnosis of recurrence between patients with discordant and concordant receptor status.

Material and Methods Patients with recurrent breast cancer treated at National Kyushu Cancer Center between January 2004 and May 2011 were reviewed retrospectively. Primary and recurrent lesions were analyzed for ER and PR by immunohistochemistry (IHC) and HER2 by IHC or fluorescence in situ hybridization (FISH). OS in discordant and concordant groups for each receptor was estimated by Kaplan-Meier method and compared by log-rank test.

Results Among 283 recurrent breast cancer patients both primary and recurrent tumor information for ER, PR, and HER2 was available in 69. Among these, recurrent biopsy specimens were obtained from locoregional recurrence in 72.5% and from distant metastases in 27.5%. Discordant rate in receptor status between the primary and recurrent tumor was 36.2%. Discordant rate in ER, PR, and HER2 was 14.4%, 23.1%, and 4.3%, respectively. Two-year OS after the diagnosis of recurrence in discordant and concordant ER group was 66.7% and 84.7%, respectively. The discordant ER group had significantly worse OS than the concordant ER group (P = 0.040). There was no significant difference in OS between the discordant and concordant PR group (P = 0.950).

Conclusions Because discordance of receptor status between primary and recurrent tumors may exist, tissue confirmation of receptor status of recurrent tumor should be considered. Japanese patients with discordant ER between primary and recurrent tumor had a poorer outcome.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-13-21.

Efficacy and safety of pregabalin for treating neuropathic pain associated with diabetic peripheral neuropathy: a 14 week, randomized, double-blind, placebo-controlled trial

AIMS

To evaluate the efficacy, safety and pharmacokinetics of pregabalin in treating neuropathic pain associated with diabetic peripheral neuropathy in Japanese patients.

METHODS

A randomized, double-blind, placebo-controlled, multicentre 14 week clinical trial was conducted. Japanese patients with diabetic peripheral neuropathy (n = 317) were randomized to receive placebo or pregabalin at 300 or 600 mg/day. The primary efficacy measure was a change of mean pain score from baseline to end-point from patients' daily pain diaries.

RESULTS

Significant reductions in pain were observed in patients treated with pregabalin at 300 and 600 mg/day vs. placebo (P < 0.05). Improvements in weekly pain scores were observed as early as week 1 and were sustained throughout the study period (300 and 600 mg/day difference from placebo at study end-point, -0.63 and -0.74, respectively). Pregabalin produced significant improvements in weekly sleep interference scores, the short-form McGill Pain Questionnaire, the Medical Outcomes Study-Sleep Scale, the 36-item Short-Form Health Survey scale, and the Patient and Clinical Global Impression of Change. Patient impressions of numbness, pain and paraesthesia were also significantly improved. Regarding treatment responders, 29.1 and 35.6% of patients treated with 300 and 600 mg/day, respectively, reported ≥ 50% improvement in mean pain scores (vs. 21.5% for placebo). Pregabalin was well tolerated; somnolence (26%), dizziness (24%), peripheral oedema (13%) and weight gain (11%) were the most common adverse events and generally were reported as mild to moderate.

CONCLUSIONS

Pregabalin was effective in reducing pain and improving sleep disturbances due to pain, and was well tolerated in Japanese patients with painful DPN.

Abstract P3-14-12: High Risk of Recurrence in Japanese Patients with HER2-Positive T1N0 Breast Cancer

Background: The necessity of adjuvant trastuzumab therapy for patients with T1N0M0 tumors remains controversial. The objective of this study is to determine the risk of recurrence in Japanese women with T1N0 HER2- positive tumors compared with HER2-negative tumors. Methods: Among 1,180 patients with breast cancers diagnosed at our institution between 2001 and 2007, we reviewed 464 T1N0M0 diseases in which HER2 status was evaluated by IHC or gene amplification, who had not received trastuzumab in the adjuvant setting. Recurrence free survival (RFS) was estimated using the Kaplan-Meier method and compared with the log-rank test. Cox proportional hazards models were used to determine the association of each group with the risk of recurrence. Results: Seventy-nine (17%) of 464 patients had HER2-positive tumors and remaining 385 (83%) were HER2-negative diseases. Patients who had HER2-positive tumors tended to be younger (P=0.015), have more hormone receptor-negative tumors (P&lt;0.001), and have higher histological grade (P&lt;0.001). At a median follow-up of 46 months, 18 patients had experienced recurrences. The 5-year recurrence-free survival (RFS) rates were 88.2% and 97.2% in patients with HER2-positive and HER2-negative tumors, respectively (P&lt;0.001). In patients with T1bN0 tumors and T1cN0 tumors, HER2-positive group had worse RFS than HER2-negative group (P=0.004 and P=0.002, respectively), while there were no differences in the RFS between patients with T1aN0 HER2-positive and HER2-negative tumors (P=0.835). In a multivariate analysis, HER2 status was identified as one of the independent risk factors to predict RFS in patients with T1N0M0 breast cancers (hazard ratio 5.23; 95% CI, 2.07 to 13.21; P&lt;0.001). Conclusion: Japanese women with T1bcN0M0 HER2-positive breast cancer have a significant high risk of recurrence, and adjuvant trastuzmab therapy should be considered for those patients.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-14-12.

Risk of relapse and failure after retreatment with the Category II regimen in Nepal

SETTING

Kathmandu Valley urban area, Nepal.

OBJECTIVE

To study the probabilities of failure and relapse and of amplifying drug resistance to isoniazid (INH) and rifampicin (RMP) after the Category II retreatment regimen.

DESIGN

Cohort study of smear-positive tuberculosis (TB) retreatment cases.

RESULTS

Of 250 cases started on Category II retreatment, 209 were relapse cases; of these, 18 were INH-resistant RMP-susceptible, 18 were INH+RMP-resistant and nine were culture-negative. Of 19 return after interruption cases, two were INH-resistant RMP-susceptible and one was INH+RMP-resistant. Among 22 failures, no case was INH-resistant RMP-susceptible, six were INH+RMP-resistant and 14 were culture-negative. No INH-susceptible RMP-resistant cases were observed. Among 182 INH+RMP-susceptible cases, one failed and four relapsed during follow-up. Two of the five cases became INH+RMP-resistant and the remaining three remained susceptible. Among 20 INH-resistant RMP-susceptible cases, two failed and none relapsed. One of the two became INH+RMP-resistant and the other case remained INH-resistant RMP-susceptible.

DISCUSSION

The proportion of resistance among retreatment cases in Kathmandu Valley was not high. The risk of relapse with amplification of RMP resistance among INH-resistant RMP-susceptible cases on the Category II retreatment regimen was 5% (1/20), and that among INH+RMP-susceptible cases was 1% (2/182).

Use of the QuantiFERON-TB Gold test for screening tuberculosis contacts and predicting active disease

OBJECTIVE

To evaluate the performance of the QuantiFERON(R)-TB Gold (QFT-G) test for screening tuberculosis (TB) contacts and estimating their risk of progressing to active TB disease.

METHODS

Data on clinical progression to active disease were collected from public health centres 2 years after close contacts of TB cases had been QFT-G-tested.

RESULTS

Among 3102 contacts observed, 419 were QFT-G-positive, and isoniazid (INH) treatment was initiated in 323. Twenty (4.8%) of these 419 developed TB disease. Among 2683 QFT-G-negative persons, 19 were diagnosed with TB (0.7%) during the average follow-up period of 1.6 years. The estimated sensitivity of QFT-G in detecting contacts who would progress to active TB was 51%, or 64% allowing for the effects of INH treatment. Among the QFT-G-negative contacts, all those who developed TB disease were contacts of highly infectious cases. Large-scale tuberculin skin testing was not available.

CONCLUSIONS

TB incidence among QFT-G-positive contacts was higher than among QFT-G-negative contacts, but the number of TB cases among QFT-G-negative contacts is non-negligible, especially among contacts of highly infectious cases.

Minimally invasive video-assisted thoracoscopic lobectomy for better clinical outcomes in peripheral T1NO lung cancer

It is an unresolved issue whether various thoracotomies affect clinical outcomes. In addition, a wide variety of technical approaches of video-assisted thoracic surgery depend on the facility. We reviewed 152 consecutive patients with clinical T1N0M0 lung cancer that underwent three types of lobectomy with systematic mediastinal lymphadenectomy in a single institute: 46 conventional thoracotomies (OPEN), 50 anterolateral small thoracotomies mainly using the thoracoscope as a light guide (ASSIST), and 56 minimum thoracotomies in which only a thoracoscope view was used (PURE). Total discharge from the chest drainage tube, length of hospital stay, and post-thoracotomy pain were significantly less in PURE than in OPEN and ASSIST. The results of mediastinal lymphadenectomy were equivalent. The 3-year survival rates were also similar among the three groups. We conclude that good clinical outcomes, especially reduced post-thoracotomy pain, seemed to correlate with the lesser degree of destruction of the chest wall with the identical quality as an acceptable cancer operation in PURE.

Trends of delays in tuberculosis case finding in Japan and associated factors

SETTING

Nationwide tuberculosis (TB) registry in Japan, 1987-2002.

OBJECTIVE

To clarify the trends of patient's delay (PD), doctor's delay (DD) and total delay (TD), their relation and factors associated with the delays.

DESIGN

Longitudinal study on trends in delays. Among patients with symptomatic smear-positive pulmonary TB, those with long PD (> or =2 months), DD (> or =1 month) and TD (> or =3 months) were analysed.

RESULTS

Long PD rates increased until around 1997, whereas long DD rates decreased markedly from 1995 to 1999. Long TD rates increased until 1997, and decreased slightly thereafter. Men aged 30-59 years had higher rates of long PD, and the long PD rates increased through the 16-year observation period. Day labourers receiving or applying for welfare benefit had the highest rate of long TD, 46.5% during 1995-2002. Teachers and medical doctors showed the greatest increase in long TD rates through the period.

CONCLUSION

Long TD was influenced more by PD than DD, and showed an upward trend. However, the long TD rate has declined slightly owing to the recent reduction in long DD. The reduction in DD since 1995 occurred immediately after the introduction of new technology in bacteriological examinations.

Development of acquired drug resistance in recurrent tuberculosis patients with various previous treatment outcomes

SETTING

Chiang Rai province, Northern Thailand.

OBJECTIVE

To study the probability of acquiring drug resistance to isoniazid (H) and rifampicin (R) on recurrence after treatment success, default and failure, among sputum smear-positive pulmonary tuberculosis (TB) patients treated with standardised short-course chemotherapy.

DESIGN

Retrospective analysis of registration records of TB patients from May 1996 to December 2000 in Chiang Rai, where routine drug susceptibility testing (DST) is conducted for surveillance purposes. Patients registered twice or more were examined.

RESULTS

Of 59 cases treated with HRZE/HR who underwent DST at the time of registration, 31 were fully susceptible to H and R at first registration, of whom four acquired drug resistance to H or R. Of 13 cases resistant to H or R at first registration, 11 became multidrug-resistant (MDR). The remaining 15 patients were original MDR cases. Among 28 MDR or H- or R-resistant cases, six reverted from resistant to susceptible.

DISCUSSION

A high proportion of patients with H- or R-resistant TB became MDR after treatment with 2HRZE/HR. Using this regimen, MDR may increase in a population with a high prevalence of H or R resistance. We are unable to explain why some drug-resistant cases became drug-susceptible. Further investigation is necessary.

Current epidemiological trend of tuberculosis in Japan

OBJECTIVE

To observe the recent epidemiological trend of tuberculosis and to determine the factors related to the deteriorating trend in incidence and mortality rates in Japan.

DESIGN

Descriptive analyses of tuberculosis notification rates and mortality rates by age, sex, year and birth-cohort.

RESULTS

The decline in the tuberculosis notification rate has started slowing down since around 1980. Among the cohorts born before 1950, the trend of notification rate by age has levelled off since around 1980. The reduction in the tuberculosis mortality rate has also recently begun to slow down, but later and to a lesser extent than that of the notification rate. Although deaths due to tuberculosis occur mostly among the elderly, the rate of decline in mortality among middle-aged males has slowed down recently. The trend in the mortality rate of birth-cohorts has recently shown an upward trend with age.

CONCLUSION

A major cause of the current stagnation of the decline in notification rates is the increase in the elderly population with a high prevalence of tuberculosis infection in the past, who are more likely to develop the disease as they approach biological senescence. Other possible causes are a gradual shift of the tuberculosis problem to socio-economically deprived segments of the urban population, and behavioural changes causing delay in case-finding.

Change of migration time and separation window accompanied by field-enhanced sample stacking in capillary zone electrophoresis

When field-enhanced sample stacking was used in capillary zone electrophoresis (CZE) analysis of cations, the decrease of migration time and the reduction of separation window was observed with increase of sample plug length. A simple equation expressing the migration velocity in the stacking process was derived to explain the above phenomenon. From experiments and theoretical consideration, we confirmed that this effect was caused by the higher potential gradient and larger eletroosmotic flow (EOF) mobility at the sample plug than those at the supporting electrolyte. A mathematical model appropriate for the computer simulation of such a system was studied considering the experimental results, and it was concluded that electroosmotic velocity (v(eof)) should be introduced to the equation of continuity as a constant.

Prevalence of drug-resistant tuberculosis in an HIV endemic area in northern Thailand

SETTING

Chiang Rai Province in Northern Thailand, where human immunodeficiency virus (HIV) infection has been prevalent since the 1990s.

OBJECTIVE

To observe the prevalence of drug-resistant tuberculosis (TB) and investigate the factors related to the level of drug resistance in an HIV endemic area.

DESIGN

Population-based surveillance study covering the whole province.

METHOD

Drug susceptibility testing was performed at the Thai Ministry of Public Health laboratory for all sputum smear-positive TB patients diagnosed in hospitals in Chiang Rai Province over a 25-month period in 1996-1998. Patient characteristics were obtained through interview by trained personnel. HIV testing was performed with informed consent.

RESULTS

Among the 1077 incident patients without previous history of treatment, the proportion of patients with resistance to isoniazid was 13.2%, 10.8% to rifampicin, 15.6% to streptomycin, and 5.8% to ethambutol. Multidrug resistance (MDR), i.e., resistance to at least both isoniazid and rifampicin, was observed in 6.3%. Factors associated with primary MDR-TB were HIV positivity (OR 2.2, 95%CI 1.3-3.9), age <50 years (OR 2.0), and treatment in the provincial hospital (OR 2.3), compared to patients treated in the community and private hospitals. Stratified analysis shows a significantly high prevalence of primary MDR-TB among HIV-positive patients treated in the provincial hospital against HIV-negative patients or HIV-positive patients in other hospitals.

CONCLUSION

The prevalence of primary MDR-TB in this area was high. It is necessary to strengthen TB control activities in order to reduce the burden of MDR-TB.

[Limits of nucleic acid amplification tests for diagnosis of smear negative pulmonary tuberculosis]

STUDY OBJECTIVES

To assess the usefulness of commercial kits of nucleic acid amplification test (NAAT) for diagnosis of smear negative (SN) pulmonary tuberculosis.

DESIGN AND PATIENTS

Retrospective study of patients who were diagnosed as, or suspected of pulmonary tuberculosis during 3 years from January 1996 to December 1998 in Fukujuji Hospital which has 100 beds for tuberculosis patients.

MEASUREMENTS AND RESULTS

145 smear-negative culture-positive pulmonary tuberculosis patients are entered to our analysis. The DNA-based amplification test kit (Amplicor Mycobacterium Tuberculosis Test (AMPL), Roche Diagnostic Systems, Basel, Switzerland) detected 39.2% (20/51, 95% confidence interval (CI): 25.8-52.6%) of smear-negative culture-positive (SNCP) pulmonary tuberculosis cases. The RNA-based amplification test kit (Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (AMTDT), Gen-Probe Inc., San Diego, Calif., USA) detected 40.5% (15/37, 95% CI: 24.7-56.3%) of SNCP pulmonary tuberculosis cases. For both NAATs (AMPL and AMTDT), between two groups with and without the NAAT at diagnosis of SNCP pulmonary tuberculosis, there was statistical difference in culture-positive rate (proportion of positivity in sputum culture tests at diagnosis), but no statistical difference in maximum number of colony of Mycobacterium tuberculosis (MTB). When stratified for the culture-positive rate, adjusted sensitivity for SNCP patients was 44.2% (AMPL) and 40.4% (AMTDT) respectively. On the other hand, among 245 patients with sputum AMPL positive results during the 3 years, 8 were smear-negative culture-negative (SNCN), only one out of these 8 cases was judged as true active tuberculosis without treatment. Among 89 patients with sputum AMTDT positive results, 7 were SNCN, and 3 out of them were judged as true active tuberculosis without treatment.

CONCLUSION

Usefulness of commercial NAAT kits (AMPL and AMTDT) to diagnosis SN pulmonary tuberculosis is limited in the point of sensitivity.

[Cost effectiveness analysis of isoniazid preventive therapy to the contacts of tuberculosis patients under Japanese settings]

The target for isoniazid preventive therapy against tuberculosis in Japan has been contact persons of tuberculosis patients with the age of less than 30. This paper discusses about the cost effectiveness analysis of preventive therapy with the mathematical model. The effectiveness was measured with averted tuberculosis cases, averted death, averted loss of DALY (disability adjusted life years), averted loss of healthy years of life. With all indicators, isoniazid preventive therapy was effective if preventive chemotherapy is given to persons younger than 70 years old and with the higher probability of new infection than 20%, and if it is given following the present criteria of tuberculin testing for preventive therapy in Japan. The total medical cost is cheaper among persons with the preventive therapy than those without the preventive therapy, if the probability of new infection among the contact persons is more than 29% at the age of 40. The isoniazid preventive therapy for health care workers, whose prevalence of infection is higher than the average population, was also effective in both cases with and without baseline tuberculin testing. However, the positive predictive value of criteria of preventive therapy highly depends on the probability of new infection.

Standardization of capillary zone electropherograms obtained by using field enhanced sample stacking

Migration times in a capillary zone electropherogram obtained by using the field enhanced sample stacking technique are strongly affected by the injected sample volume. That is, the migration times significantly decrease with the increase of the sample volume. To avoid inaccurate qualitative analysis due to the above phenomena, the time axis of the electropherograms was converted into an effective mobility axis using our conversion method taking account of the temperature increase in the separation tube and relaxation of the potential gradient of the separation field. After the conversion, accurate qualitative analysis was possible in spite of drastic change of the migration time, suggesting our conversion method could be successfully used for the standardization of electropherograms obtained even by using the stacking effect. The cause of the decrease of the migration time in the stacking process was briefly discussed.

New method for standardization of electropherograms obtained in capillary zone electrophoresis

A new method for standardization of electropherograms obtained by capillary zone electrophoresis was proposed, where the migration time axis was replaced by the effective mobility axis. The mobility increase due to temperature increase by Joule heating and the relaxation effect of the potential gradient were eliminated successfully by introducing a temperature coefficient for mobility expression and a delay time, respectively. The precision of the mobility evaluated by the proposed conversion methods was evaluated for a model sample. By using the conversion method, almost the same electropherograms could be obtained even from the electropherograms originally obtained by using different hardware conditions.

[Epidemiology and control activities of tuberculosis in Japan]

Tuberculosis has declined in Japan for 50 years, however it is more prevalent than other developed countries and speed of decline is much slower recently in Japan than in European countries in 1950-80s when the incidence rate was almost the same as that in Japan now. Most of old cases were reactivation and most of young cases were those soon after new infection. Early case detection and treatment and cutting the chain of transmission is necessary for the reduction of young cases. The defaulter rate among smear positive new cases is 3.6% and is higher among non-skilled workers. DOT has not been widely done on outpatient clinic basis but should be considered for those who cannot stay in hospitals.

[Cross-contamination of Mycobacterium tuberculosis culture in clinical laboratories]

For many years, it has been thought that positive culture of M. tuberculosis is a definitive diagnostic evidence of tuberculosis and cross-contamination of M. tuberculosis culture in clinical laboratories is rare. However recently introduced RFLP analysis has enabled us to identify a strain of M. tuberculosis, and many cases of the cross-contamination in clinical laboratories confirmed by RFLP analysis have been reported. In this report, we present the first case of the cross-contamination confirmed by RFLP in Japan. In our case, 5 patients without any personal link to each other were suspected based on clinical findings to have cross-contaminated results of M. tuberculosis culture. All their specimens were processed on the same day, and were smear negative and culture positive with only a small number of colonies (less than 8 colonies). The sputum from the suspected source of contamination processed on the same day was strongly positive for AFB smear and heavily culture positive. The RFLP patterns of these 6 patients were identical, so it was concluded that the positive cultures of the sputum from the 5 patients who were not expected to be culture positive on clinical findings were caused by the cross-contamination in our hospital laboratory. We review all the charts of patients with M. tuberculosis culture positive results in the same year of this case, but we didn't find no other cases suspected of the cross-contamination. Then we reviewed the literature of M. tuberculosis culture cross-contamination. The patterns of the cross-contamination are divided into two. One is associated with malfunction of a sampling needle in the BACTEC 460 system and the other associated with the initial processing of the specimens, mostly involving reagents such as NaOH solution. Cross-contaminated specimens are usually smear negative with only a few colonies (less than 5), and processed just after the source specimen of the contamination in most reported cases, but not in all. In almost half of them the cross-contamination results had significant influence on the clinical management. The frequency of the cross-contamination is estimated around 1% of the patients with M. tuberculosis culture positive results. For early detection of the cross-contamination, not only clinicians but also laboratory staffs have important role and close cooperation between them is mandatory. To prevent the contamination, it is advisable to process smear positive and probable culture positive specimens separately from others, and not to use a large same container of reagents for processing of different specimens.

[Current epidemiological trend of tuberculosis among foreigners in Japan]

In Japan, the proportion of foreign patients among the total tuberculosis patients is still very small, but their problems in tuberculosis case finding and treatment require intensive control activities as in other low prevalence countries with higher proportion of foreign-born cases. The latest national survey for the foreign tuberculosis patients conducted in 1996 shows the epidemiological status between 1990 and 1993. The number of foreign tuberculosis patients in 1993 was 484, consisting of 1.0% of the total new patients in Japan. The new case rate among foreigners was estimated to be 53 per 100,000 against 38 for whole Japan in 1993. Compared with the figure in the 1993 survey, the number of foreign patients declined from 585 in 1992 to 484 in 1993. However, the number of bacillary positive tuberculosis patients in 1992 was 230 and almost the same as in 1992. The decline or stagnation of total number of tuberculosis patients can be due either to the decrease in the foreign population inflow into Japan (real decline), or partially to the reduction of overdiagnosis in X ray examination and the possible loss of some cases in the 1996 survey method. A manual sorting method from the registration cards was used at each public health center, since there is no item of country of origin in the routine tuberculosis surveillance system, and some cards might have already been displaced by the time of the survey for patients who were excluded from the registry, either cured, died or defaulted. The average treatment completion rate (1991-93) among foreign patients was 51%, which was much lower than the national figure of 81% for the same years. Moreover the rate showed deteriorating trend by year. For more accurate information, the foreigner's data must be taken in the national tuberculosis surveillance system and control activities for foreigners need to be strengthened.

[Six-months chemotherapy (2HRZS or E/4HRE) of new cases of pulmonary tuberculosis--six year experiences on its effectiveness, toxicity, and acceptability]

The incidence of tuberculosis in Japan, 33.7 per 100,000 in 1997, is very high compared with USA or Western European countries. The decrease in the incidence has slowed down from the early 1980s, and the average annual rate of decrease has been 3.8% in the last 5 years. About 9 percent of tuberculosis patients defaulted from the nine-month regimen (6HRS or E/3HR) in urban areas. Regimens shorter than nine-month are needed to achieve high effectiveness of tuberculous chemotherapy. Out of 1128 new pulmonary tuberculosis patients, six-hundred twenty started treatment with six-month (2HRZS or E/4HRE) in Fukujuji Hospital, JATA, in Tokyo from January 1991 to December 1996. Out of 620, four-hundred twenty eight were both smear and culture positive, 136 were smear negative and culture positive and 56 were bacilli negative. Out of 564 bacilli positive cases, 530 were susceptible to INH and RFP. Out of 530 drug susceptible cases three hundred ninety-three patients completed the regimen. Ninety-three percent of these patients had converted to negative at two months of chemotherapy and all of them at five months. Out of 450, two-hundred ninety five completed 6-month regimen, one-hundred fifty-five were changed their regimen or prolonged duration of chemotherapy. Out of 295, nine patients (3.1%) relapsed after the completion of 6-month chemotherapy. Mean follow-up period was 17.2 months and the median was 15.5 months. The relapse rate was 2.2 per 100 person-years. Six of the relapsed cases were complicated with Diabetes Mellitus. Relapse rate was higher in patients with Diabetes Mellitus than in patients without (6/54, 7.9 per 100 person-years vs 3/237, 0.8 per 100 person-years) (p < 0.001). Drug-induced hepatotoxicity was defined as elevated serum transaminase level with clinical symptoms of hepatitis or elevated serum transaminase level more than 5 times of upper limit of normal range with or without symptoms. Drug-induced hepatotoxicity developed in 43 (8.0%) of 535 with initial normal liver function test results, this rate was similar to that in patients treated with nine-month regimen (34/420, 8.1%). But the frequency of hepatotoxicity of more than 400 IU/ml of serum transaminase level was higher in patients treated with PZA-containing regimen than with nine-month regimen (16/536, 3.0% vs 4/420, 1.0%), but this deference was not statistically significant. Hepatotoxicity developed in 13/85 (15.3%) of patients treated with PZA-containing regimen with abnormal liver function tests at the beginning of chemotherapy, and this frequency was similar to 7/65 (10.8%) in patients with nine-month regimen. The relapse rate in patients with Diabetes Mellitus was statistically higher than in without Diabetes Mellitus (7.9 vs 0.8 per 100 person-years). We concluded that the six-month regimen was highly effective, but the frequency of severe hepatotoxicity was relatively higher than in nine-month regimen and the duration of chemotherapy was not enough for patients complicated with Diabetes Mellitus. Further study is needed for sufficient chemotherapy in patients with Diabetes Mellitus.

[Severe hypoxia due to persistent left supra vena cava draining to the left atrium after weaning from cardiopulmonary bypass in a patient with endocardial cushion defect]

We report a case of severe hypoxia after weaning from cardiopulmonary bypass in a ten-month-old patient with endocardial cushion defect. The severe hypoxia was improved abruptly when the persistent left supra vena cava (PLSVC) was ligated. The hypoxia, therefore, was considered to be caused by venous blood which was directly drained into the left atrium through the PLSVC. In cases with large right-to-left shunt which is difficult to explain only by intracardiac shunt, attention must be paid to existence of PLSVC directly draining into the left atrium.

[Comparison of double-segment technique with single-space technique for cesarean section using combined spinal epidural anesthesia]

In patients scheduled for cesarean section (c-section) using combined spinal epidural anesthesia (CSEA), we compared the cephalad spreading speed during double-segment technique (DST) with that of single-space technique (SST) of CSEA. In the patients of SST group (n = 169), a 17-G Tuohy needle was introduced at the L 3-4, and then a long spinal needle was inserted through the Tuohy needle. In the patients of DST group (n = 16), a Tuohy needle was introduced at the T 11-12, and a spinal needle was inserted at the L 3-4. After 0.3% hyperbaric dibucaine 1.0 ml was injected through the spinal needle, 1.5% mepivacaine 10 ml was injected through the epidural catheter in both the groups. The analgesic level was measured at 5-min intervals, and blood pressure and complaints of patients were also recorded. The cephalad spread of analgesia was significantly higher in DST group than in SST group at 5 and 10 min after the administration of local anesthetics. Two patients in SST group, epidural catheterization was not possible. There were no difference in the incidences of hypotension, nausea and dyspnea between the groups. We conclude from these results that DST for CSEA is preferable to SST for c-section.

[Multidrug-resistant tuberculosis. 3. Epidemiology of drug-resistant tuberculosis in Japan]

In Japan, the frequency of drug-resistant tuberculosis has been investigated every 5 years since 1950s and increase of initial and acquired drug resistance has not been observed. However, the mathematical model analyse of time trend of prevalence of drug-resistant tuberculosis and frequency of initial drug resistance in Korea shows that there is little difference of infectivity and/or proportion of clinical breakdown between susceptible bacilli and resistant ones. The prognosis of isoniazid (INH) and rifampicin (RFP) resistant tuberculosis cases in Fukujuji Hospital was investigated. 367 cases including 50 initial drug resistant cases were analyzed with life table analysis. 50% of all cases and 70% of initial drug resistant cases became negative, 13% of all cases and 4% of initial drug resistant cases remained as positive, 37% of all cases and 27% of new cases died. Among cases who did not convert negative within one year, 41% of all cases and 34% of initial drug resistant cases died. The prognosis of INH and RFP resistant tuberculosis cases were still not satisfactory.

Endothelium-dependent and -independent vasodilation of isolated rat aorta induced by caffeine

Caffeine (10(-4)-10(-3) M) induced concentration-dependent relaxations of phenylephrine-precontracted rat aortic rings with endothelium. Endothelial denudation significantly, but only partially, attenuated caffeine-induced relaxation. Pretreatment with NG-nitro-L-arginine, oxyhemoglobin, and methylene blue attenuated the relaxations to an extent similar to endothelial denudation. Guanosine 3',5'-cyclic monophosphate (cGMP) and adenosine 3',5'-cyclic monophosphate (cAMP) contents of aortic strips with endothelium increased significantly after exposure to caffeine (10(-3) M). Endothelial denudation attenuated caffeine-induced cGMP increase. Pretreatment with ryanodine (2 x 10(-5) M), which has been shown to combine with receptors on endoplasmic reticulum (ER) of endothelium, attenuated caffeine-induced relaxation and cGMP content increase of rings with endothelium. Pretreatment with caffeine potentiated sodium nitroprusside-induced relaxations and cGMP increase of rings without endothelium. These results demonstrated that caffeine-induced relaxation comprises two components. In the endothelium-dependent mechanism, caffeine promotes nitric oxide synthesis in endothelium by release of Ca2+ from ER through a ryanodine-sensitive Ca2+ channel, and the suppression of cGMP degradation also contributes to the relaxation. In the endothelium-independent mechanism, caffeine acts as a 3',5'-cyclic-nucleotide phosphodiesterase inhibitor.

[Efficacy of the standard regimen for initial treatment of pulmonary tuberculosis: results of long-term followed-up]

In 1986, the regimen with isoniazid, rifampicin and streptomycin or ethambutol for 9 or 6 months was introduced as the standard therapy for the initial treatment of pulmonary tuberculosis in Japan. Since then, several reports have been published on the relapse rate after such standard regimen, but follow-up observation was limited to relatively short period in these studies, except one study. Further, none of these studies reported overall efficacy rate of the treatment which was the most important index to evaluate the regimen. So we investigated the deaths, defaults, treatment failures, and relapses during and after the initial treatment of pulmonary tuberculosis patients to calculate the efficacy rate. Three hundred and six patients with newly diagnosed pulmonary tuberculosis, who had admitted to Fukujuji Hospital and started initial treatment with standard regimen, were followed-up, retrospectively. At the start of the initial treatment, mean age of the male patients were 47.0 and those of the female patients were 42.2 years old (male: 232 cases, female: 74 cases). Of the total 306 patients, 84.5% were basically positive and 50.7% were cavitary tuberculosis. Resistance to isoniazid, rifampicin, streptomycin and ethambutol was noticed in 3.5%, 0.4%, 4.3% and 0.4% of the patients tested. Their medical records in Fukujuji Hospital were reviewed, and for the patients who had not visited the hospital more than one year letters were sent to request to visit the hospital and to answer to questionnaire. The questionnaire were also sent to the referred hospitals and the concerned health-centers. Of 306 patients enrolled in the present investigation, 7 have dropped out.(ABSTRACT TRUNCATED AT 250 WORDS)

Severe respiratory depression after epidural morphine in a patient with myotonic dystrophy

We describe a patient with myotonic dystrophy who underwent cholecystectomy, and developed severe respiratory depression following epidural administration of morphine to provide postoperative analgesia. At preoperative assessment, he demonstrated near normal vital capacity and maximal voluntary ventilation, but the presence of chronic ventilatory failure with a resting value of PaCO2 51 mmHg. Anaesthesia was produced by a combination of epidural and light general anaesthesia without intravenous anaesthetics, narcotics or neuromuscular relaxants. Five hours after epidural administration of 2 mg morphine, the patient developed severe respiratory depression with a PaCO2 of 93 mmHg. Intravenous naloxone resulted in transient improvement in minute volume, suggesting that epidural morphine was responsible for the depression. Epidural morphine can cause unexpected respiratory depression, even at a small dose, because of the sensitivity of the respiratory centre to morphine in patients with myotonic dystrophy.

[Influence of bronchoscopic examinations on the statistics of tuberculosis incidence]

The frequency of the modes of bacteriological examinations other than direct sputum smear were observed for a total of 955 "smear-positive" pulmonary tuberculosis cases which were notified at 7 health centres in the Metropolitan and suburban areas during 1986-1990. Of them 21 cases (2.2%) were examined for the specimens obtained by bronchofiberscopic procedures, and in 4 cases (0.4%) gastric juice was taken. The proportion of the non-sputum positivity as seen above was higher in females than in males, but it was uniform across all age group. Non-cavitary cases showed higher proportion of the non-sputum positivity than cavitary cases. There was wide variation in the frequency of these aggressive modes of examination among health centres, probably indicating the difference in the extent to which hospitals are interested in these modes of examination in each health center area. In addition to the above observed cases, there were 60 cases with direct smear positive finding of mycobacteria other than tuberculosis (MOTT). They account for 5.9% of all of 1,015 new notifications of AFB-smear positive cases. It is possible that these non-sputum "smear positive" cases, as well as the MOTT-smear positive cases may be underestimated in our study, because of the notification form not necessarily requesting to enter the type of bacteriological examinations. They may contribute to the recent upward trend of incidence rate of smear positive tuberculosis in Japan to a considerable extent.(ABSTRACT TRUNCATED AT 250 WORDS)

[Drug-induced psychiatric disturbance by lidocaine]

Lidocaine is widely used as an antiarrhythmic agent. One of the side effects of lidocaine is disorientation. Measurement was made of the plasma level of lidocaine in twelve consecutive cases. Lidocaine infusion had been given to these cases for more than twenty-four hours. Measurements were then made of the frequency of psychiatric disturbance. Psychiatric disturbances were recognised in six cases and the plasma levels in four cases among them were more than 5 micrograms.ml-1. The psychiatric disturbances disappeared within three hours after the cessation of lidocaine infusion. When disorientation occurs in a patient who receives lidocaine treatment, drug-induced psychiatric disturbance should be suspected.