Age-period-cohort analysis on tuberculosis cases in Japan, 1953-2022.

Background: Age-period-cohort (APC) analysis has been employed to differentiate long-term trends in the incidences of communicable diseases, including tuberculosis (TB), into the effects of age, birth year, and calendar period. However, no such study was hitherto conducted for Japan, which has 70 years of surveillance data. Therefore, we conducted APC analysis for TB in Japan. Methods: The national TB data for 1953-2022 were analyzed using the log-transformed linear model of APC analysis. Results: Annual age-and sex-standardized notification rates of TB peaked at 599.0 per 100 000 population in 1955 and fell by 99% to 4.5 in 2022. Adjusting for the effects of the birth cohort and period, the relative age-effect risk of TB peaked at 20-29 years and went down toward 60-69 years. Regarding the birth cohort effect, the TB risk showed a turning point in approximately 1913 for the central years of birth. Another change appeared in 1963 when the decline of the risk slightly stagnated; then, it started declining again at a rate as fast as in 1923-1953. Period effects showed a hump in the late 1950s and early 1960s, then sharply declined to the late 1970s, and reached a near plateau level until 2022. Conclusion: Our results highlight the continuing peak in TB disease risk for young adults and sharp decrease in disease risk in the 1960s and 70s. The introduction of anti-TB drugs in the 1950s and early 1970s had the most important impact on the epidemiology of TB in Japan.

Tuberculosis in older adults: case studies from four countries with rapidly ageing populations in the western pacific region.

BACKGROUND: The Western Pacific Region has one of the fastest-growing populations of older adults (≥ 65 years) globally, among whom tuberculosis (TB) poses a particular concern. This study reports country case studies from China, Japan, the Republic of Korea, and Singapore reflecting on their experiences in managing TB among older adults. FINDINGS: Across all four countries, TB case notification and incidence rates were highest among older adults, but clinical and public health guidance focused on this population was limited. Individual country reports illustrated a range of practices and challenges. Passive case finding remains the norm, with limited active case finding (ACF) programs implemented in China, Japan, and the Republic of Korea. Different approaches have been trialled to assist older adults in securing an early diagnosis, as well as adhering to their TB treatment. All countries emphasised the need for person-centred approaches that include the creative application of new technology and tailored incentive programs, as well as reconceptualisation of how we provide treatment support. The use of traditional medicines was found to be culturally entrenched among older adults, with a need for careful consideration of their complementary use. TB infection testing and the provision of TB preventive treatment (TPT) were underutilised with highly variable practice. CONCLUSION: Older adults require specific consideration in TB response policies, given the burgeoning aging population and their high TB risk. Policymakers, TB programs and funders must invest in and develop locally contextualised practice guidelines to inform evidence-based TB prevention and care practices for older adults.

Epidemiology of latent tuberculosis infection in Japan-born and foreign-born children in Japan.

Objective: This study aims to compare the epidemiology of notifications of latent tuberculosis infection (LTBI) among Japan-born and foreign-born children in Japan between 2010 and 2020, and to assess the language used during LTBI case interviews with parents or caregivers of foreign-born children with LTBI during 2019. Methods: Our study consisted of two parts: (1) an analysis of national data from the Japan Tuberculosis Surveillance (JTBS) system on the epidemiology of LTBI among Japan-born and foreign-born children in Japan, and (2) a survey of staff at public health centres that had registered at least one foreign-born child aged ≤ 14 years with LTBI. Data were extracted from the JTBS system for all children aged ≤ 14 years who were newly notified as having LTBI between 2010 and 2020, and analysed to determine trends, characteristics and treatment outcomes. Staff at relevant public health centres completed a self-administered survey. Results: A total of 7160 Japan-born and 320 foreign-born children were notified as having LTBI between 2010 and 2020. Compared with Japan-born children, foreign-born children notified as having LTBI were more likely to be older, have their mother or sibling as their source of infection and have LTBI detected via a routine school health check. At case interviews, the use of language interpretation services was limited, even when both parents were non-Japanese. No interview was directly conducted with children themselves, not even with school-aged children. Discussion: Foreign-born children and their parents may be unfamiliar with the system of testing for TB infection and the diagnosis of LTBI in Japan in school settings. Public health centres are required to provide education to patients and their families and care that takes into account cultural and linguistic differences. However, the provision of language support during case interviews may need strengthening.

Practices and attitudes towards tuberculosis and latent tuberculosis infection screening in people living with HIV/AIDS among HIV physicians in Japan.

BACKGROUND: Tuberculosis (TB) continues to be the leading cause of death for people living with HIV/AIDS (PLHIV), and HIV is the strongest known risk factor for progression to active TB disease for persons with latent TB infection (LTBI). Screening for active TB and LTBI, and TB preventive therapy (TPT) is recommended, however, clinical practices regarding LTBI screening for HIV positive population have not been uniform, resulting in low rates of LTBI screening and TPT uptake, in both low and high TB-burden countries. We sought to explore the practices and attitudes towards TB and LTBI screening in PLHIV among HIV physicians in Japan. METHODS: We conducted a cross-sectional survey whereby an on-line questionnaire was administered to physicians who are currently, or have the experience of, providing care and treatment for PLHIV in Japan. RESULTS: The questionnaire was sent to a total of 83 physicians, of which 59 responded (response rate; 71.1%). 52.5% (31/59) conducted routine screening and 44.0% (26/59) conducted selectively screening for active TB among HIV/AIDS patients. As for LTBI, 54.2% (32/59) conducted routine screening and 35.6% (21/59) conducted selective screening for LTBI among PLHIV. "T-SPOT only" was the most frequently used method of screening (n = 33), followed by "QFT only" (n = 11). Criteria for LTBI screening included TB burden in the country of birth of the patient, previous contact with a TB patient, and CD4+ cell count. 83.1% (49/59) either "always" or "selectively" offered TPT to PLHIV diagnosed with LTBI, and among the 49 respondents who did provide TPT, 77.6% (38/49) chose 9-months isoniazid as their first choice. None chose regimen including rifampicin. CONCLUSIONS: Our study revealed that practices regarding TB and LTBI screening and treatment for PLHIV among HIV physicians were mixed and not necessarily in accordance with the various published guidelines. Building and disseminating scientific evidence that takes into consideration the local epidemiology of TB and HIV in Japan is urgently needed to assist physicians make decisions.

Characteristics and Treatment Outcomes among Migrants with Pulmonary Tuberculosis: A Retrospective Cohort Study in Japan, 2009-2018.

This study aimed to describe characteristics and treatment outcomes of overseas-born pulmonary tuberculosis (PTB) patients in Japan, and identify the factors associated with "treatment non-success". We conducted a retrospective analysis of overseas-born patients with drug-susceptible PTB using cohort data of PTB cases newly registered in the Japan tuberculosis (TB) surveillance system between 2009 and 2018. Overall, 9151 overseas-born PTB cases were included in this study, and 70.3% were aged 34 years old or younger. "Students of high school and higher" (28.6%) and "regular workers other than service related sectors" (28.5%) accounted for over half of the study population, and they have continued to increase. Overall, the treatment success rate was 67.1%. Transferred-out constituted the largest proportion (14.8%) among the treatment non-success rate (32.9%). Multiple logistic regression analysis revealed patients whose health insurance type was "others and unknown", including the uninsured (adjusted OR (AOR) = 3.43: 95% Confidence Intervals (CI) 2.57-4.58), those diagnosed as TB within "one year" (AOR = 2.61, 95% CI 1.97-3.46) and "1-5 years" (AOR = 2.44, 95% CI 1.88-3.17) of arrival in Japan, and males (AOR = 1.34, 95% CI 1.16-1.54), which were the main factors associated with treatment non-success. These findings imply that Japan needs to develop TB control activities considering the increasing trends of overseas-born PTB patients, the majority of whom are young and highly mobile. There is a need to pay greater attention to overseas-born PTB patients diagnosed within a short duration after entering Japan, who may be socially and economically disadvantaged for their treatment completion.

Epidemiology of coinfection with tuberculosis and HIV in Japan, 2012-2020.

This report examines the characteristics and treatment outcomes of patients with tuberculosis (TB) who are coinfected with HIV in Japan. Active TB cases newly notified to the Japan Tuberculosis Surveillance system during 2012-2020 were analysed retrospectively, during which 379 HIV-positive TB cases were reported. The proportion of HIV-positive cases among those with known HIV status increased, from 1.9% (62/3328) in 2012 to 3.5% (31/877) in 2020. The proportion of those with unknown HIV testing status was consistently high, at approximately 60%, and the proportion of those who did not undergo HIV testing increased significantly, from 21.6% (4601/21 283) in 2012 to 33.7% (4292/12 739) in 2020. The proportion of foreign-born cases more than tripled, from 14.5% (9/62) in 2012 to 45.2% (14/31) in 2020. The TB treatment success rate was higher among HIV-negative than HIV-positive cases (72.7% [3796/5222] versus 60.3% [88/146]), and among Japan-born than foreign-born HIV-positive patients (65.6% [61/93] versus 50.9% [27/53]), owing largely to the high rate of foreign-born cases transferring to care outside Japan. The increasing proportion of HIV positivity among TB cases tested for HIV in this study requires ongoing monitoring, especially among foreign-born persons. However, because the number of reported cases was small, and there was low completeness of reporting of HIV testing data in the TB surveillance system, these results should be interpreted with caution. Encouraging more complete data collection by training public health nurses who complete TB case interviews and ensuring ongoing monitoring of patients with TB/HIV coinfection are recommended.

Epidemiology of childhood tuberculosis after ceasing universal Bacillus Calmette-Guérin vaccination.

Universal Bacillus Calmette-Guérin (BCG) vaccination is recommended in countries with high tuberculosis (TB) burden. Nevertheless, several countries have ceased universal BCG vaccination over the past 40 years, with scarce comparative epidemiological analyses regarding childhood TB after the policy change. We analysed data on childhood TB in countries that ceased universal BCG vaccination. Data sources included national/international databases, published papers, annual TB reports, and public health authority websites. Childhood TB notification rate increased in one of seven countries with available data. Pulmonary TB and TB lymphadenitis were the main causes of increasing childhood cases, while changes in severe forms of TB cases were minor. Maintaining high vaccine coverage for the target group was a common challenge after shifting selective vaccination. In some countries showing no increase in childhood TB after a BCG policy change, the majority of childhood TB cases were patients from abroad or those with overseas parents; these countries had changed immigration policies during the same period. Heterogeneity in childhood TB epidemiology was observed after ceasing universal BCG vaccination; several factors might obscure the influence of vaccination policy change. Lessons learned from these countries may aid in the development of better BCG vaccination strategies.

A diffused community tuberculosis outbreak that could be detected earlier using surveillance data, Japan, 2012-2014.

Background: Early detection of an outbreak is a role of disease surveillance systems; however, tuberculosis (TB) surveillance systems were underutilized to detect the outbreaks. In mid-2015, a local health office of central Japan noticed the number of TB cases of city in 2012-2014 were well above the expected numbers. This study was conducted to determine whether and when a community TB outbreak could be detected and characterize the cases using the national surveillance data. Method: The surveillance data of the A city and surrounding areas were retrospectively reviewed and analyzed for 2006-2018. Results: The TB notification rates of the A city from 2012 to 2014 were 28.0 (95% confidence interval [CI]: 20.3-38.4), 26.0 (95%CI: 18.6-36.0), 28.2 (95%CI: 20.3-38.4) per 100,000 population, respectively, higher than that of the entire prefecture (13.6, 13.0, 13.3, respectively). Similarly, in the neighboring B city, the rates of 2012 and 2014 were 51.0 (95%CI: 27.2-87.2) and 51.2 (95%CI: 27.3-87.5), respectively, higher than that of its parent prefecture (13.4 and 12.7, respectively). By the end of July 2012 (A city) or August 2012 (B city), the accumulated numbers of TB cases exceeded the previous annual TB cases. The average TB notification rates of A and B cities for 2012-2014 were higher than the surrounding areas. Conclusion: A community TB outbreak without well-defined setting could be detected by monitoring TB surveillance data.

Prevalence of SARS-CoV-2-Specific Antibodies, Japan, June 2020.

We used 2 commercially available antibody tests to estimate seroprevalence of severe acute respiratory syndrome coronavirus 2 infection in Japan during June 2020. Of 7,950 samples, 8 were positive by both assays. Using 2 reliable antibody tests in conjunction is an effective method for estimating seroprevalence in low prevalence settings.

Trend and treatment outcomes of latent tuberculosis infection among migrant persons in Japan: retrospective analysis of Japan tuberculosis surveillance data.

BACKGROUND: Screening for latent tuberculosis infection (LTBI) among migrant population has become a critical issue for many low tuberculosis (TB) burden countries. Evidence regarding effectiveness of LTBI programs are limited, however, partly because of paucity of national data on treatment outcomes for LTBI. In Japan, notification of LTBI is mandatory, and its treatment outcome is reported as part of Japan's national TB surveillance system. We thus conducted a detailed analysis of LTBI among foreign-born persons, to update the epidemiological trend of newly notified LTBI between 2007 and 2018, and to examine the treatment regimen and outcome of those notified in 2016 and 2017, focusing specifically on the potential risk factors for lost to follow-up. METHODS: We extracted and analyzed the data of newly notified LTBI patients from the Japan Tuberculosis Surveillance System to examine the overall trend of notification and by age groups and modes of detection between 2007 and 2018, and the cohort data for treatment regimen and outcomes of foreign-born persons notified with LTBI in 2016 and 2017. Trends and proportions were summarized descriptively, and logistic regression analysis was conducted to identify potential risk factors for lost to follow-up. Comparisons were made with the Japan-born patients where appropriate, using chi-squared tests. RESULTS: Both the number and proportion of LTBI among foreign-born persons have been constantly increasing, reaching 963 cases in 2018. Cohort analysis of the surveillance data indicated that the proportion of those on shorter regimen was higher among the foreign- than Japan-born patients (5.5% vs. 1.8%, p < 0.001). The proportion of those who have been lost to follow-up and transferred outside of Japan combined was higher among the foreign- than Japan-born patients (12.0% vs, 8.2%, p < 0.001). Risk factors for lost to follow-up were being employed on a temporal basis, and job status unknown (adjusted odds ratios 3.11 and 4.09, 95% confidence intervals 1.34-7.26 and 1.60-10.48, respectively). CONCLUSIONS: Migrant population face greater risk of interrupting LTBI treatment, and interventions to improve adherence are a critical component of programmatic management of LTBI. Further studies are needed to explore the cultural and socioeconomic situation in which foreign-born persons undergo LTBI treatment in Japan.

Residual Destructive Lesions and Surgical Outcome in Mycobacterium avium Complex Pulmonary Disease.

BACKGROUND: Successful surgical treatment of patients with Mycobacterium avium complex pulmonary disease is thought to require complete removal of parenchymal destructive lesions. This study aimed to evaluate the short-term and long-term outcomes and the predictors of microbiological recurrence after surgery for M avium complex pulmonary disease. METHODS: We conducted a retrospective review of 184 patients undergoing unilateral lung resection for M avium complex pulmonary disease at a single center in Japan between January 2008 and December 2017. RESULTS: Median age of the 184 patients was 55.5 years; 133 were female (72.3%). All but 2 patients had anatomical lung resection. A total of 116 patients had limited disease and underwent complete resection (63.0%); the remaining 68 patients had extensive disease and underwent debulking surgery (37.0%). No operative mortalities occurred. In 18 of 184 patients, 21 morbidities occurred (9.8%), including 3 bronchopleural fistulas (1.6%). Postoperative sputum-negative status was achieved in 183 patients (99.5%). Microbiological recurrences occurred in 15 patients (8.2%). By multivariate analysis, extensive disease was an independent risk factor for recurrence (hazard ratio, 5.432; 95% confidence interval, 1.372-21.50; P = .016). Recurrence-free rates were significantly higher in patients with limited disease compared with those with extensive disease (99.0%, 97.4%, and 95.0% versus 93.0%, 89.2%, and 75.1% at 1, 3, and 5 years, respectively; P < .001). CONCLUSIONS: Complete resection of parenchymal destructive lesions can achieve excellent microbiological control for patients with limited M avium complex pulmonary disease. The efficacy of debulking surgery in patients with extensive disease needs further investigation.

Population-based survey of antimycobacterial drug use among patients with non-tuberculosis mycobacterial pulmonary disease.

This report shows poor adherence to the recommended treatment regimen for NTM-PD patients, which may pose a potential risk for the development of macrolide resistance. The risk was highest among elderly patients, and those with rheumatoid arthritis and COPD. http://bit.ly/3aBoUzE.

Reconstructing the population dynamics of foreign residents in Japan to estimate the prevalence of infection with Mycobacterium tuberculosis.

Among newly notified tuberculosis cases in Japan, both the number and the proportion of foreign-born cases have steadily increased over time. As Japan prepares to introduce pre-entry tuberculosis screening for foreign-born persons entering Japan, various epidemiological evidence is needed to evaluate its effectiveness, including the prevalence of tuberculosis among current foreign residents in Japan, by country of birth. Yet as of today, even the underlying population dynamics has yet to be quantified. The present study therefore aimed to firstly reconstruct the demographic prevalence of foreign residents by the length of stay in Japan and by country of birth, and secondly, to estimate the prevalence of infection from notification data among foreign residents in Japan. We employed the McKendrick partial differential equation model to reconstruct the dynamics among six Asian countries which account for 80% of foreign-born tuberculosis patients notified in Japan i.e. China, the Philippines, Vietnam, Nepal, Indonesia, and Myanmar. Compared with China and the Philippines, the recent remarkable increase in the number of residents who had arrived within 5 years from Myanmar and Vietnam was identified. Assuming that the risk of primary tuberculosis given infection is 5%, the estimated prevalence of infection ranged from 3.5% to 21.3%, and all the estimates were more than three times greater than the crude estimate that ignored the time since immigration. The proposed method may be used to further estimate the prevalence by age, sex and residential status, which could potentially provide critical evidence towards establishing policies to control tuberculosis among foreign-born persons in Japan, and also possibly among migrants globally.

Delay in health-care-seeking treatment among tuberculosis patients in Japan: what are the implications for control in the era of universal health coverage?

OBJECTIVE: To study the trends in and risk factors for patient delay (the time from the onset of symptoms to the initial doctor visit) in pulmonary tuberculosis (PTB) using three temporal categories - short (2 weeks to < 2 months), medium (2 months to < 6 months) and long (≥ 6 months) - and discuss implications for social protection measures. METHODS: A descriptive cross-sectional study was conducted by analysing Japanese TB surveillance data from patients with symptomatic PTB registered between 2007 and 2017 (n = 88 351). RESULTS: While the proportion of patients with short delay has decreased significantly (P < 0.001), the proportions of those with medium or long delays have decreased slightly (P = 0.0015 and P < 0.001, respectively). Not having health insurance, receiving public assistance, being a temporary worker, and having a history of homelessness were some of the risks identified for patient delay. Being male and working full-time were two risks specifically associated with long delay (for males, the adjusted odds ratio = 1.17, P < 0.05; for being a full-time worker, the adjusted odds ratio = 1.72, P < 0.05). DISCUSSION: Despite the implementation of universal health coverage decades ago, patient delay remains a challenge in Japan. Our study identified various risk factors, many of which could have been resolved if appropriate social protection measures were in place, indicating shortcomings in universal health coverage in Japan and the need for continued effort to ensure that no one is left behind.

Whole-genome sequencing-based epidemiological analysis of anti-tuberculosis drug resistance genes in Japan in 2007: Application of the Genome Research for Asian Tuberculosis (GReAT) database.

We investigated the lineages of Mycobacterium tuberculosis (Mtb) isolates from the RYOKEN study in Japan in 2007 and the usefulness of genotypic drug susceptibility testing (DST) using the Genome Research for Asian Tuberculosis (GReAT) database. In total, 667 isolates were classified into lineage 1 (4.6%), lineage 2 (0.8%), lineage 2/Beijing (72.1%), lineage 3 (0.5%), and lineage 4 (22.0%). The nationality, gender, and age groups associated with the isolates assigned to lineage 1 were significantly different from those associated with other lineages. In particular, isolates of lineage 1.2.1 (EAI2) formed sub-clusters and included a 2,316-bp deletion in the genome. The proportion of the isolates resistant to at least one anti-tuberculosis (TB) drug was 10.8%, as determined by either the genotypic or phenotypic method of DST. However, the sensitivities to isoniazid, streptomycin, and ethambutol determined by the genotypic method were low. Thus, unidentified mutations in the genome responsible for drug resistance were explored, revealing previously unreported mutations in the katG, gid, and embB genes. This is the first nationwide report of whole-genome analysis of TB in Japan.

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.

Epidemiology of Adults and Children Treated for Nontuberculous Mycobacterial Pulmonary Disease in Japan.

RATIONALE: The epidemiology of nontuberculous mycobacterial pulmonary disease (NTM-PD) remains unclear in the majority of countries, including Japan. OBJECTIVES: To estimate the nationwide incidence and prevalence of NTM-PD in Japan and to describe case characteristics and geographical variation. METHODS: In this cross-sectional study, we analyzed data from all health insurance claims made for NTM-PD collected from the National Database in Japan between 2009 and 2014. A patient with NTM-PD was identified on the basis of at least one claim submitted with International Classification of Diseases Version 10 codes associated with NTM-PD and at least one claim for combinations of antimycobacterial medications. We calculated the incidence and prevalence rates for 2011 by sex, age group, and geographical region and evaluated comorbidities. RESULTS: The numbers of incident and prevalent NTM-PD cases in 2011 were 11,034 (8.6 per 100,000 person-years; 95% confidence interval [CI], 8.5-8.8) and 37,063 (29.0 per 100,000 persons; 95% CI, 28.7-29.3), respectively. Among incident cases, the mean ± standard deviation age was 69.3 ± 12.3 years, and 69.6% were women. The incidence rate sharply increased after 50 years of age in both sexes and was higher among women in all age groups, except for those aged 80 years and above. Among men, the incidence rate was highest among older adults, with a sharp increase in comorbidities with age. The most prevalent comorbidities were bronchiectasis for women and chronic obstructive pulmonary disease for men. Most southwestern regions showed high incidence rates, except for Okinawa, which is the southernmost island in Japan. CONCLUSIONS: Our results revealed that the incidence and prevalence rates of NTM-PD were among the highest worldwide, despite the conservative treatment-based case definition of NTM-PD used in this study. Prolonged disease duration accompanied by comorbidities probably affected this high prevalence rate. Older adults and women had an especially high risk of NTM-PD, but older men with comorbidities also require more attention. Further studies are required to investigate the factors underlying this geographical variation.

Evaluation of "international transfer-out" among foreign-born pulmonary tuberculosis patients in Japan - what are the implications for a cross-border patient referral system?

BACKGROUND: Tuberculosis (TB) patients crossing borders pose a serious challenge to global TB control efforts. The objectives of our study were firstly, to evaluate the trend and size of foreign-born pulmonary TB patients, who had been notified and initiated treatment in Japan but have transferred out of the country while still on treatment; and secondly, to conduct a detailed analysis of these patients and identify possible risk factors for international transfer-out, and discuss policy implications for a cross-border patient referral system for foreign-born TB patients in Japan. METHODS: We conducted a cross-sectional study whereby aggregated cohort data of pulmonary TB cases newly notified to the Japan TB Surveillance system between 1 January 2011 and 31 December 2015 were analyzed. Multinomial logistic regression analysis was conducted to identify and compare the risk factors for international transfer-out. RESULTS: Among the 668 foreign-born patients whose treatment outcome had been evaluated as "transferred- out", 51.3% has in fact moved to outside Japan between 2011 and 2015. The proportion of such international transfer-out of total foreign-born patients who had transferred out has more than doubled during the study period, from 23.3% in 2011 to 57.7% in 2015. Some of the risk factors for international transfer-out were being a full-time worker (Relative risk [RR] 2.86, 95% confidence interval [CI] 2.04, 3.99), being diagnosed within 0 to 2 years of arriving to Japan (RR 8.78, 95% CI 4.30,17.90) and within 3 to 5 years (RR 7.53, 95% CI 3.61, 15.68), sputum smear positive (RR 1.95, 95% CI 1.53, 2.48), and coming from Indonesia (RR 1.86, 95% CI 1.13, 3.03). CONCLUSIONS: Providing continuity of care for mobile population is one of the keys to achieving the WHO's End TB Strategy targets for 2030, and results of our study indicate that a cross-border referral system should be an integral part of TB control among foreign-born persons in Japan.

The profile of prisoners with tuberculosis in Japan.

Purpose Although globally, prisoners are considered one of the vulnerable groups to tuberculosis (TB), little is known about the situation of TB in prison setting in Japan. The purpose of this paper is to examine the characteristics of TB among prisoners in Japan. Design/methodology/approach Records of TB patients from one medical prison were analyzed in terms of general demographic characteristics, clinical manifestations, risk factors and delay in diagnosis and in initiating treatment, and compared with data from the national TB surveillance and other published data on health of inmates, where appropriate. Continuous variables were compared using student independent samples t-test. Proportions were compared using χ2 or Fisher exact test as appropriate. Kaplan-Meier survival analysis was conducted to determine the time from entry to prison institution to diagnosis of TB. Findings A total of 49 patients were analyzed. The mean age was 49.5 (±14.3) and 69.4 percent were males. Being unemployed and homeless prior to incarceration, and several co-morbidities were potential risk factors for TB ( p<0.01). Analysis of diagnosis and treatment delay showed that 16.1 percent of smear positive patients took more than a week to be placed on treatment after being diagnosed of TB. Approximately 50 percent of the patients were diagnosed within four months of entering the prison institution. Practical implications Several potential risk factors identified suggest the need to strengthen screening for specific sub-groups within the prison population, such as those with poor socio-economic status and co-morbidities, as well as to consider the possible role of systematic screening for latent TB infection. Originality/value This study presents some important data to help understand the profile of TB patients in prisons in Japan, as well as showing that a detailed epidemiological analysis of existing records can provide useful insight.