新しい結核対策 国立感染症研究所ハンセン病研究センター

摘要

The 1951 Tuberculosis Control Law of Japan was amended extensively and has been in effect since April, 2005. The revision of the National Tuberculosis Program (NTP) is to respond to the tremendous changes that have occurred during the last 50 years in tuberculosis epidemiology and in the environment in tuberculosis control implementation. In this review, the main points and framework of the revisions were summarized and the perspective of the development of new technical innovations relevant to each area of the revised TB control legislation is discussed. Also,challenges of Japan's NTP in the recent future are discussed,including the controversies over the proposed abolishment of the Tuberculosis Control Law,1.Immunization, In the revision of NTP,the BCG vaccination of elementary school and junior-high school entrants was discontinued. In order to strengthen the early primary vaccination for infants, the new Law has adopted the direct vaccination scheme omitting tuberculin testing prior to immunization. This program is implemented to young babies, i.e.less than six months old,as defined by the decree. It is a heavy responsibility for the municipalities to ensure the high coverage of immunization when the period of legal vaccination is rather strictly limited practically to the fourth to sixth months after birth.The safe direct vaccination is another new challenge where appropriate management of the Koch's phenomenon or similar reactions should be warranted.2Chemoprophylaxis,Though unfortunately suspended for some legal reason currently,the expansion and improvement of chemoprophylaxis,or treatment of latent tuberculosis infection, to cover anyone with higher risk of clinical development of TB would have a tremendous effect in Japan, especially since 90% of patients who developed TB were infected tens of years ago. The technical innovations in diagnosis of TB infection such as QuantiFERON will be very helpful, Development of new drugs or drug regimens for this purpose is also expected.3.Case detection. The "indiscriminate" screening scheme in the periodic mass health examination has been replaced with a selective one.Only subjects aged 65 or older are eligible for the screening, supplemented with selected occupational groups who are considered to become source of infection,should they develop tuberculosis,such as health-care providers and school teachers. Local autonomies are also responsible for offering screening to the socio-economic high-risk populations,such as homeless people,slum residents, day laborers,and/or workers in small businesses,as decided by the autonomies at their disposal. Another important mode of active case-finding,i,e, contact investigation has been legally enforced so that anybody cannot refuse to be examined by the Health Center. This investigation service will be greatly enhanced by such new technologies as DNA fingerprinting of TB bacilli and a new diagnostic of TB infection. Regarding the clinical service of the symptomatic patients that detect 75% of new cases currently will be improved in its quality by introducing an external quality assurance system of commercial bacteriological laboratory services.4.Treatment and patient support: The revised NTP clearly states the government's responsibility for treating TB patients in close cooperation with a doctor, in the framework of the DOTS Japan version. While the development of new anti-tuberculosis drugs will be realized in the near future, Japan still has to overcome the issues of improper practice of treatment, as well as the government's slow process for approving drugs to be used for multi-drug resistant TB and non-tuberculous mycobacterioses, such as quinolones,macrolides and others.5.Prefectural TB Control Plan:In order to respond to the specific issues of tuberculosis problem in the respective prefectures in terms of epidemiology or in available resources,the Law requests every prefecture to develop and implement its own TB control plan.The rath