[National surveys of the prevalence of tuberculosis disease--overview, progress and lessons learnt]

This is a summary of an invited lecture at the 88th annual assembly of the Japanese Society for Tuberculosis on 28 March 2013. The lecture was carried out in Japanese. The WHO's Global Task Force on TB Impact Measurement was established in June 2006 to produce a robust, rigorous and widely-endorsed assessment of whether the 2015 targets for reductions in TB incidence, prevalence and mortality are achieved at global and regional levels and in individual countries; to regularly report on progress towards these targets in the years leading up to 2015; and strengthen national capacity in monitoring and evaluation of TB control. Three major and inter-related areas of work were defined and working groups were established to cover each of these areas, Surveillance, Prevalence surveys, and Estimates of TB burden, in 2007. x-ray screening and culture diagnosis between 2007 and today (March 2013). At least six countries are expected to launch a survey in 2013, and seven are already in a pipeline to launch one in 2014. These surveys provide an unbiased estimation of disease burden that is often higher than it was thought when the survey was planned especially in Asian countries. Surveys are also providing a rich source of data to inform programme policy and strategy: In this lecture, lessons learnt from surveys in China, Cambodia and Myanmar were discussed to show impact of DOTS as well as its limitations and challenges caused by rapidly ageing populations in Asia. An overall synthesis of the main implications of the results from recent prevalence surveys implemented in Asia and Africa for post-2015 global TB policy and strategy is also in the pipeline. The summary results and implications will be widely disseminated from 2014 when the results of the surveys in African countries are finalized.