Osaka City has the highest tuberculosis (TB) notification rates in Japan. In the period 1999–2003, the TB control programme was strengthened, and the Stop TB Strategy was implemented to reduce the number of notified cases. The objective of this study was to assess the effect of these control activities in Osaka City, including the implementation of directly observed treatment (DOT), by analysing TB surveillance and routinely collected data. We reviewed the surveillance data of all sputum smear-positive pulmonary tuberculosis (PTB) cases registered in the Osaka City Public Health Office from 2001 to 2008 and data collected from the routine TB programme. The DOT implementation rate increased from 0% in 2001 to 68% in 2008 for smear-positive PTB cases of the general public and to 61% for all PTB cases of the homeless. The proportion of smear-positive PTB cases that had treatment failure and default combined, declined from 8.0% (52 of 650) in 2001 to 3.6% (20 of 548) in 2006. The proportion of cases among the homeless with previous treatment declined from 28% in 2001 to 15% in 2008. The proportion of cases with multidrug resistant-TB (MDR-TB) among those without previous treatment declined from 1.7% in 2001 to 0.9% in 2008. It is logical that reduction in the failure and default rate would lead to the reduction of cases with previous treatment and TB transmission, including resistant TB, therefore to the reduction of MDR-TB rates.

Objective: To identify individual characteristics related to the development of pulmonary tuberculosis (PTB) among residents in the Airin area (Airin), Osaka City, Japan. Methods: We conducted a retrospective case-control study of individual characteristics potentially related to the development of PTB by comparing PTB patients and residents without tuberculosis (TB) in Airin. The following binominal data of characteristics were compared: age (<65 or >65); body mass index (BMI) (<18.5 or >18.5); diabetes mellitus (diagnosed or not diagnosed); smoking (currently smoking any amount or not smoking); and alcohol use (currently drinking any amount or not drinking). Results: We compared the individual characteristics of 192 PTB patients notified from January 2015 to December 2018 and 190 residents of supportive houses who attended a health education programme from April 2016 to March 2018. Univariable analysis showed that the following characteristics were significantly related with PTB: BMI <18.5 (odds ratio [OR]: 6.54, 95% confidence interval [CI]: 3.58–11.97, P < 0.001) and current alcohol use (OR: 1.88; 95% CI: 1.24–2.85, P = 0.003). Multivariable analysis showed similar results: BMI <18.5 (adjusted odds ratio [aOR]: 6.90, 95% CI: 3.72–12.79, P < 0.001) and current alcohol use (aOR: 2.15, 95% CI: 1.36–3.42, P = 0.001). Discussion Undernutrition and alcohol use are individual characteristics associated with PTB among residents in Airin, Osaka City. To strengthen the TB control programme further, it is suggested to develop new programmes for primary prevention.

Objective: To determine the characteristics associated with mortality in patients with culture-positive pulmonary tuberculosis (PTB) in Airin, Osaka City, Japan. Methods: The characteristics of patients with culture-positive PTB registered between 2015 and 2018 in Airin, Osaka City, Japan, were compared between those who died of all causes before or during treatment and those who completed treatment. Results: Of the 241 culture-positive PTB patients eligible for this study, 170 completed treatment, with negative sputum culture tests, and 62 died. The all-cause case fatality rate was 26.7% (62/232). Multivariate analysis showed that mortality was associated with age >70 years, having a positive sputum smear, a body mass index of <18.5 and serious comorbidities such as cancer and heart and renal disease. Detection of tuberculosis (TB) by screening or in an outpatient department (OPD) for other diseases was inversely associated with mortality. Discussion: Detection of PTB by chest X-ray screening and during regular visits to OPDs for other diseases was associated with non-fatal TB and might contribute to early case finding. Therefore, current active TB case finding and health education on regular visits to physicians for other diseases should be strengthened further for the urban poor population of Osaka City, Japan.