Computerized surveillance system of tuberculosis in Japan: its evolution, achievement and challenges.

The nationwide computerized tuberculosis (TB) surveillance system was revised in 2007. It was developed to be user-friendly and to allow the evaluation of current TB problems and control issues in Japan. All public health centers in Japan (518 as of April 2007) have system terminals connected to a central computer, and the data entered at these terminals are sent to the online central computer excluding personal identification data. All the figures and tables in this paper were created using the annual report database which are compiled from this system. The revision in 2007 added many new functions to the system, such as a function for automatically sending data upon transfer. The monitoring information for assisting case management of TB patients by the DOTS was also enhanced. The algorithm for classifying treatment outcomes automatically based on data entered regarding cancellations from registration, bacteriological results and drug usage each month was revised. The proportion of "Failed" and "Defaulted" combined was 4.6% among new sputum smear positive pulmonary TB patients newly registered in 2009, while "Died" accounted for as high as 19.3%, due largely to a high percentage of the elderly. A new system for contact examination management is provided as a subsystem. Feedback of data analyses has been strengthened by various methods. This TB surveillance system is indispensable for implementing the evidence-based TB control program in Japan. An important role of the Research Institute of Tuberculosis is to support the planning and execution of TB control with provision of useful epidemiological information from the system.