1. The role of prevalence surveys in measuring the burden of TB, progress in TB control and improving early case detection Ikushi Onozaki WHO/STB/TBS Global Task Force on TB Impact Measurement DEWG meeting, Oct 13-14 2009, Geneva

2.  Background  Task Force recommendations  What is needed to implement a survey and what can surveys tell us?  Current status of survey implementation  Next steps Content

3.  TB prevalence is an MDG indicator that can be directly measured in HBCs  Estimation of TB burden using tuberculin surveys no longer applicable in most settings  Funding is available for surveys, and governments and international agencies recognize importance of measuring impact Background

4. Task Force recommendations

5. Countries where surveys are recommended 21 global focus countries 36 additional countries that met basic criteria

6. How should surveys be implemented? Follow the guidelines!

7. Recommended screening strategy Do smear and culture at least for with TB symptoms and/or abnormal chest X-ray

8. What is needed to implement a survey?

9. ( WHO headquarters, March 2008)

10.  Sample size : 30,000- 60,000  Cluster size: 500-1,000  12-15 staff per field team for 6–10 months, 3-4 team operation  Costs ~ US$1 million in Asia, US$2 million in Africa Capital investment (CXR, Lab, Cars), Human Resource (Salaries), Survey Operation (Field and Central), Pre & Post survey events, technical assistance What is required for a survey?

12. Go to the community

13. Survey day Transport people to X-ray site

14. Individual interview by trained health professional from central unit TB related symptoms TB history –Possible treatment –Consultation Places Risk factors

16. Develop and read images on the Spot Quality Direct X-ray is Available in Villages that contributed to high participation rates and 100% sputum collection from suspects

17. Prevalence Survey in Viet Nam Digital technology was introduced for the first time to National Scale TB survey

18. Smear Microscopy Direct Smear, ZN LED-FL Collect, Store, Transport and Put in Culture within 5 days Lab work

19. What can be learned from a survey?

20. A carefully designed survey can tell you lots more than TB prevalence Changes in TB burden and re-estimation of burden Performance of strategies for screening of TB suspects Health-seeking behaviour of TB patients and individuals reporting chest symptoms Where and why are cases missed by the NTP e.g. access to care, role of private sector Risk factors

21. Prevalence of Sm+ TB in Cambodia, 2002, was half of previous estimate and previous study results Prevalence of S+ in Yangon, Myanmar, nearly 3 times previous national estimate -> National Survey Prevalence of S+ in Viet Nam, 2007, was 60% more than previous estimate  Prevalence Surveys can help to revise and improve estimates of disease burden and CDR Re-estimation of TB Burden

22. Strategies for screening TB suspects NTP Cambodia. National TB Prevalence Survey Report, 2002. 2005, ** H Ayles et al. Plos one May 2009. e 5602, *** NTP Viet Nam. Presented in UNION APR Conference, Beijing, Sept 2009 40-60% of confirmed cases in surveys do not have chronic cough

23. Smear microscopy alone misses >50% of bacteriologically-confirmed TB *Africa 5 sub-national surveys average

24. Where are cases being missed? 33 in NTP: around 130/100,000 = 260/100,000/year Yangon survey, 2006: 1/3 of TB patients being treated by GPs

25. Current status of survey implementation

26. Good progress in Asia

27. No survey in Africa started yet – urgent action required!! HBC Other countries preparing: Ghana, Malawi, Mali, Rwanda, Togo, Zambia,

28. Next steps

29. Workshop on prevalence surveys in 12 African countries, 15-16 October 2009 Identification of bottlenecks holding up survey implementation Lessons from Asia How to solve the bottlenecks Role of Task Force partners in providing technical assistance to countries