Transmission of tuberculosis and predictors of large clusters within three years in an urban setting in Tokyo, Japan: a population-based molecular epidemiological study.

OBJECTIVE: Molecular epidemiology is a promising tool for understanding tuberculosis transmission dynamics but has not been sufficiently utilised in Asian countries including Japan. The aim of this study was to estimate the proportion of TB cases attributable to recent transmission and to identify risk factors of genotype clustering and the development of large clusters within 3 years in an urban setting in Japan. DESIGN AND SETTING: Long-term cross-sectional observational study combining the characteristics of patients with culture-positive TB notified in Shinjuku City, Tokyo (2002-2013), with genotype data of Mycobacterium tuberculosis. PRIMARY OUTCOME MEASURE: Genotype clustering rate and association between genotype clustering status and explanatory variables. RESULTS: Among 1025 cases, 515 were localised within 113 genotype clusters. The overall clustering rate was 39.2%. Significantly higher rates were found in patients aged <40 years (adjusted odds ratio (aOR)=1.73, 95% CI 1.23 to 2.44), native Japanese individuals (aOR=3.90, 95% CI 2.27 to 6.72), full-time workers (aOR=1.63, 95% CI 1.17 to 2.27), part-time/daily workers (aOR=2.20, 95% CI 1.35 to 3.58), individuals receiving public assistance (aOR=1.81, 95% CI 1.15 to 2.84) and homeless people (aOR=1.63, 95% CI 1.02 to 2.62). A significant predictor of large genotype clusters within 3 years was a registration interval ≤2 months between the first two cases in a cluster. CONCLUSION: Our results indicated that a large proportion of patients with culture-positive TB were involved in the recent TB transmission chain. Foreign-born persons still have a limited impact on transmission in the Japanese urban setting. Intensified public health interventions, including the active case finding, need to focus on individuals with socioeconomic risk factors that are significantly associated with tuberculosis transmission and clusters with shorter registration intervals between the first two cases.

[EFFECT OF EDUCATIONAL LEAFLETS ON KNOWLEDGE AND ATTITUDE TO TUBERCULOSIS AMONG HOMELESS PERSONS IN TOKYO, JAPAN].

SETTING: Delay in seeking care is one of the critical issues in tuberculosis (TB) control among homeless persons in Japan. Yet knowledge of and attitude towards TB among homeless persons have remained unclear and limited efforts have been made to disseminate information related to TB among homeless persons. OBJECTIVE: To evaluate the effect of TB leaflets, produced and distributed to homeless persons by a group of ex-homeless TB patients, and to understand what homeless persons know about TB. DESIGN: Self-administered questionnaire was conducted among homeless persons before and after distribution of the TB leaflets. Changes in the responses to each question were also subjected to principal component analysis to group questions into types according to response patterns and identify constructs of TB-related knowledge. RESULTS: Results of 88 participants were analyzed. TB knowledge score related to risks and symptoms significantly improved after the intervention (from 54.3% to 70.6%, p < 0.05), while knowledge on treatment cost did not. Two components were identified, namely, the "improvement in TB impression" and "improvement in TB knowledge". CONCLUSION: TB leaflets were effective in improving certain aspects of TB knowledge. However, its effect on knowledge regarding treatment cost, which may be crucial in improving delay, was limited and thus the messages need to be revised.

[Importance of monitoring the drug dosage and treatment duration for the management of tuberculosis patients at public health centers].

PURPOSE: On the basis of actual field data, we investigated the importance of monitoring the drug dosage and treatment duration for the supportive care of patients with tuberculosis who were being treated at public health centers. PATIENTS & METHODS: Data of the drug dosage of principal anti-tuberculosis drugs and the treatment duration for the registered patients with tuberculosis at the Shinjuku-ku Public Health Center were analyzed. RESULTS: The actual dosage of rifampicin and isoniazid according to the "recommended" dosage was administered to 57.3% (67/117) and 82.0% (114/139), respectively, patients with tuberculosis registered at the Shinjuku-ku Public Health Center. In contrast, in patients with tuberculosis who were treated at a highly specialized tuberculosis hospital, the rates were 81.0% (98/121) and 93.5% (86/92), respectively; for both drugs, the rates were significantly higher in this hospital than in the Shinjuku-ku Public Health Center. For the treatment duration, of 92 patients registered at the Shinjuku-ku Public Health Center who could have completed standard treatment in the standard duration, the actual treatment durations were shorter than the standard duration in 15.2% of the patients (14/92; -32 to -1 days), and longer than the standard duration in 77.2% (71/92; 2 to 146 days); the total superfluous treatment days for the latter 71 patients were 1,877 days. The treatment durations were more than 2 weeks shorter or longer than the standard duration for 31 patients, and in 71.0% (22/31) of these patients, no specific reason could be determined as to why the treatment durations were not standard. CONCLUSION: In a significant number of patients, the drug dosage and treatment duration were not according to the standard values. By using this data about the management of the drug dosage and treatment duration for the supportive care of patients with tuberculosis treated at public health centers, we may improve quality of the provided supportive care.

[On-the-street DOTS for a homeless tuberculosis patient--case report of a patient who had difficulties with TB treatment adherence].

PURPOSE: A homeless patient with tuberculosis (TB), who had often quit his TB treatment in mid-course and then gone homeless again, succeeded in completing his treatment for over 10 months through on-the-street DOTS ("Bluesky DOTS" is another expression). Based on the analysis of this case, we have discussed how to provide effective countermeasures to non-compliant TB patients. METHOD: An episode of a successful on-the-street DOTS for a 70-year-old homeless man with sputum smear positive pulmonary TB was qualitatively analyzed, with a view toward patient's empowerment. RESULT: The patient had had human-relations problems in his life, and trouble with medical and welfare service staff. During his hospital admissions, he repeatedly self-discharged or was forced to discharge due to violent behavior against staff. Public health nurses at Shinjuku public health center visited the patient frequently at the hospital, and tried to build a good relationship with the patient from the beginning of the treatment. Following a two and half month interruption of the TB treatment after he disappeared from the hospital, he was discovered staying outside at a canal side in the area, and on-the-street TB treatment was carried out, with good cooperation with the hospital and social welfare office. Directly observed TB medication was given to him by a public health nurse and another health center staff member for 293 days, at the park near his living place. The patient often rejected the medication, particularly when he was hungry, but offering lunch to him was a very effective incentive. Through comprehensive supports to the patient, he gradually changed his attitude, and on his own came to consider his health and his future. DISCUSSION: We have analyzed a successfully treated case of a homeless TB patient who had difficulties in maintaining a social life and had not been cooperative in complying with the medication. The level of independence improved during the course of on-the-street DOTS with incentive and other supports. He became receptive to TB treatment and became self-supportive during the course of DOTS, with food as an incentive. This indicates that on-the-street DOTS was successful not only for the treatment completion but also contributed to empowering the TB patient. This approach of adjusting the service to the patient's needs fostered a positive relationship with all stakeholders.

[Use of a risk assessment inventory in implementation of the community DOTS in Shinjuku, Japan].

PURPOSES: To investigate the effectiveness of a risk assessment for implementing the DOTS of outpatients in the Japanese city of Shinjuku. SUBJECTS: A total of 435 patients with tuberculosis or latent tuberculosis infection who were registered in the city of Shinjuku between 1 April 2005 and 31 December 2007. METHODS: Soon after their diagnosis or registration and again 4 months thereafter, the patients were interviewed by the public health nurse in charge using a risk assessment inventory that had 17 scales related to the risk of defaulting from the treatment. Based on the results of the risk assessment, the patients were provided with an appropriately adapted DOTS. RESULTS: Out of all patients, 386 (88.7%) were assessed twice, of whom 338 (77.7%) were those with active disease. The patients were classified into three groups according to their risk scales: high-, medium-, and low-risk groups. There was no change in the risk grouping during the 4 months in 307 (90.8%) patients. However, in 12 patients (3.6%) the risk level was increased after 4 months, because of the development of side effects and problems with regular outpatient visits. The common methods of support in drug taking were daily DOT at the health center for patients in the high-risk group, and DOT at pharmacy shops once or twice weekly with self-medication on the other days for patients in the medium-risk group. For the low-risk group, the public health nurses made interview once or twice a month. There was no significant difference in the treatment success rate, default rate, or mortality rate among these three groups. DISCUSSION: The treatment outcome suggests that the community DOTS in this area may be effective. It was important to assess possible risks in treatment for each patient in order to identify the support needs and means. Also, it is necessary to develop a good risk assessment inventory scale.

[Tuberculosis control in Shinjuku Ward, Tokyo--promoting the DOTS program and its outcome].

OBJECTIVES: The objectives were to report how to promote tuberculosis (TB) control including DOTS (Directly Observed Treatment, Short-course) programs, and to evaluate the results of TB control programs in Shinjuku Ward (Shinjuku-ku). SETTING AND CHARACTERISTICS: Inhabitants and TB patients in Shinjuku Ward. Shinjuku Ward is located in the center of metropolitan Tokyo and has typical urban TB problems, such as high incidence rate and TB among foreigners and the homeless. The TB incidence rates in Shinjuku Ward decreased from 83.9 per 100,000 population in 1999 to 42.5 per 100,000 population in 2006, however, the rates were still two times higher than the national average. Therefore, one of the important TB programs in Shinjuku has been to actively detect cases among high-risk groups such as foreigners and the homeless. METHODS: We observed the trend of case detection rates by health examination with chest X-ray among different high-risk groups, and compared the treatment outcomes before and after DOTS program execution. We also reviewed the changes of re-treatment rates and drug resistance rates. RESULTS: The case detection rates of TB by health examinations of foreign students at Japanese language schools decreased from 0.49% in 1996 to 0.13% in 2006 (p = 0.021). Although the case detection rates decreased, they were still about 26 times higher than those of Japanese students. While, the case detection rates among the homeless remained high with 4.7%, 3.3%, 4.5% and 3.6% in 1999-2002, respectively, since 2003, however, they had decreased and no TB cases were detected in 2005-2006. The DOTS program for homeless TB patients has been carried out since 2000 and that for the foreigners since 2003. The rates of defaulting during treatment before DOTS were very high among both homeless patients (21.4%) and foreigners (29.8%) in 1998-1999. However, after the introduction of DOTS program, those rates declined to 10.4% (p = 0.014) among the homeless and 7.8% (p = 0.002) among foreigners in 2002-2004. The proportion of newly notified patients with previous TB treatment and those with multi-drug resistant TB (MDR-TB) have also decreased after the introduction of DOTS programs. From 2000-2002 to 2003-2006, the re-treatment rates decreased from 19.4% to 10.0% (p < 0.001) and MDR-TB rates decreased from 1.6% to 0.2% (p = 0.042), respectively. DISCUSSION: The key points of TB control in Shinjuku Ward are to detect TB cases early especially among the high-risk groups, and to assist all TB patients to complete their treatment. In order to expand this strategy, besides promoting active case findings among high-risk groups, we have developed many types of DOTS programs, considering each patient's lifestyle and cooperating with school teachers at schools, pharmacists at pharmacies, home-care specialists at homes or facilities for the elderly, and so on. Among others, a major premise for the homeless and some other socially disadvantaged patients was to guarantee the provision of medicine and living by introducing social welfare services, before starting DOTS programs. This approach might have helped to reduce the defaulting rate, relapse rate and MDR-TB rate.

[Implementation and evaluation by a population-based RFLP analysis in an urban area, Shinjuku city, Tokyo--the possibility of application for contact investigations].

OBJECTIVES: The objectives were to examine Mycobacterium tuberculosis transmission patterns by RFLP analysis in Shinjuku city, and to elucidate more effective methods of contact investigations. METHODS: We applied RFLP analysis to 389 M. tuberculosis isolates from 402 TB patients registered in Shinjuku city from September 2002 though August 2006. RESULTS: Forty-six clusters consisting of 155 TB patients (average 3.4 people per cluster) were identified (proportion of clustering: 39.8%). The clustering rates were 34.5% among general patients, and 57.8% among homeless patients, and the latter was higher than that of non-homeless patients (odds ratio: 2.6, 95% CI; 1.6-4.1, p < 0.001). On the other hand, the clustering rates were only 19.4% among foreigners (odds ratio: 0.5, 95% CI; 0.2-1.2, p = 0.090). Twenty-eight of 46 clusters (60.9%) were consisted of mixture of general patients, homeless patients and foreigner patients. Thus, RFLP analysis can detect the transmission route which can not be identified by the routine contact examination, thus enabling contact investigations extended to the appropriate persons. DISCUSSION: The homeless clustering rate was significantly high. This suggests that the proportion of transmission among the homeless patients might be high. However, many clusters were composed of a mixture of homeless patients and non-homeless patients, so transmission patterns are not easy to identify. It is not always true that transmission of tuberculosis to non-homeless patients took place from homeless patients. Clustering rates among homeless patients are high, therefore taking countermeasures for the homeless patients is an effective way to prevent the spread of tuberculosis. Introduction of RFLP analysis is a practical epidemiological methodology to investigate the source of infection and transmission route of infection, and can be applied to contact investigations. If RFLP analysis can be applied in a larger area, yearly changes of notification rates and molecular epidemiological clustering rates will provide indices for preventive measures against tuberculosis.