A situational analysis of latent tuberculosis infection among incarcerated population in Japan

Background The World Health Organization recommends that systematic testing and screening of latent tuberculosis infection (LTBI) among the incarcerated population "should be considered", though based on evidence of either low or very low quality. However, in Japan, a TB middle-burden country, systematic screening for LTBI in correctional facilities is currently not conducted. As part of a larger study to determine the cost-effectiveness of LTBI screening in correctional facilities in Japan, this study was conducted to determine the situation of LTBI, including treatment outcome, among the incarcerated population in Japan, and provide the essential data for cost-effectiveness analysis. Method A cross-sectional study was conducted between 2017 and 2018 with public health centers which have one or more correctional facilities under their jurisdiction. Questionnaire surveys were sent to collect information on their policy of managing LTBI patients notified from correctional facilities, including whether or not there was a standardized procedure for initiating LTBI treatment, and also to collect sociodemographic information and treatment outcome of LTBI patients who were notified from the respective correctional facilities in 2015 and 2016. Results The survey was sent to a total of 163 public health centers, out of which 133 (81.6%) responded. 8 of the 133 public health centers actively guided the correctional facilities regarding LTBI treatment initiation through a standardized procedure, while 115 either had not established such procedure or were unaware of how LTBI treatment was being initiated in the correctional facilities. A total of 91 LTBI patients were notified from the correctional facilities in 2015 and 2016, and the information of 89 were available for analysis. 82 were males, and 83 were Japan-born. Treatment outcome was known for 88 patients, of which 70 had completed treatment. Of the 18 who did not complete the treatment, 15 had been lost to follow-up upon release from the facilities. Among those who had been released whilst on treatment, the proportion of those who completed the treatment was higher in those patients who received pre-release visit by a public health nurse, than those who did not. Conclusions LTBI treatment was often being initiated without consideration for the patients' prison term. The treatment completion rate within jail was high, indicating the possibility that incarcerated population can benefit for LTBI treatment. On the other hand, the completion rate decreased significantly among those who had been released while still on treatment. In order to optimize the benefit, initiation of LTBI must carefully be considered upon the patient's prison term, as well as coordination among the relevant organizations to ensure continuity of care after release.