1. National Prevalence Survey, Cambodia
4/8/2019
National TB Prevalence Survey
Cambodia, 2002
8 years after introduction of DOTS
Ikushi Onozaki　MD, MPH
Chiba Anti-TB　Association/JATA
Chiba Foundation for Health Promotion and Disease Prevention
Dr Ikushi Onozaki (CENAT/JICA National TB Control Project)

2. How much TB in Cambodia? Estimates for 2001
estimate number rate/100,000
incidence (all) ,
incidence HIV ,
incidence (ss+) ,
prevalence (all) 178,
prevalence (ss+) 72,
deaths ,
From Chris Dye

3. National TB Prevalence Survey 1st Systematic, National Representative and Comprehensive TB Survey in Cambodia
First population based survey under a typical DOTS program
42 clusters of 31,000 people across the country
30,000, 97%, participated
22,164, 96%, Age 10 or more
Age <15 y : Tuberculin
Age 10 or more: X-ray
Preparation Meeting with Local People

4. Lao
Thailand
Viet Nam
Survey Cluster:★

5. Basic Operation Schedule: Cluster/Week
Sunday: Arrival & Basic Preparation
Monday: Census/ Informed Consent
Arrival of Technical Team
Tuesday/Wednesday: Interview, X-ray, Tu-test, Sputum collection
Thursday: Interview, X-ray, Sputum collection, Sputum transfer to CENAT
Friday: Sputum collection, Tu-reading
Saturday: Tu-reading (morning only) , Departure

6. Census: Confirming eligible population and asking for participation People who basically stay in a defined area more than a month are eligible population regardless the possession of their house and their availability on the survey day
Proper informed consent to avoid creating fears

7. Survey Days
Collaboration with local community is essential

8. Family by family interview by a physician from CENAT
TB related symptoms
Duration of sickness
TB history
Possible treatment
Consultation Places
1,699 (7.7%) participants who met the TB suspect criteria such as cough more than 3 weeks were asked to submit sputum regardless X-ray findings

9. Age 10ys or more: Taking X-ray
22,012 X-ray exams
2,432 who showed any kind of abnormality were asked to submit sputum
JICA team is monitoring and ensuring the safety of the survey

10. Developing Film on the Spot Quality Direct X-ray is Available in Villages
that contributed to high participation rates and 100% sputum collection from suspects

11. 84 showed smear positive slide(s)
81 Smear Positive TB
1 MOTT
2 contamination susp.
81 S(+) TB :(71 New)
New: 66
on Treatment: 5 New, 2 Ret
Previously treated: 8
202 S(-)C(+)
190 S(-)C(+) TB Cases
12 contamination susp
190 Cases
New: 174
on Treatment: 3 New, 1 Ret
Previously treated: 13

12. Number of S(+) cases actually detected and Prevalence Rate

15. Prevalence of Bac(+) Pulmonary TB National TB Survey 2002

16. Relations between prevalence and notification smear positive TB
Ａｇｅ

17. Limitation of Symptom Screening by Interviews to Detect Cases

19. DOTS in all MPA Health Centers, primary care level per 10,000 population, by 2005

20. Prevalence of TB and Distance to DOTS Service ( /100,000 age 10 or more)

21. Point Estimates of ARI, 2002 National Survey Children with No BCG Scar (RT23:2TU)
16 mm mirror
10 mm
Age 1-4
(N=993)
0.46%
0.99%
Age 5-9
(N=2,245)
1.00%
2.10%
Age 10-14
(N=2,532)
1.62%
3.21%

22. Estimation of Incidence of New S(+)
DOTS CDR=52%, Private Tx=10%, TB/HIV: 15%

23. Conclusions and Research Questions
Yes, Cambodia has very high TB burden, however,
S(+) Prevalence, 270, a half of WHO estimate
No more among 22 HBC???, dropping from 18th to 24th?
A large pool of latent infection may be a major source of new cases: Continuous efforts are essential
30/81 S(+) were judged as no-TB suspects by interviews: Limitation of a survey without X-ray and/or CF strategy
S(+) occupied only 30% of Bac (+)
Less in groups with better access to DOTS: A transitional phenomenon of short history of DOTS? Or Need of new model?
Bac (+) prevalence of 902: Total TB burden is probably more than the WHO estimate that may make Cambodia still within 22 HBC, even 16th or 17th ?

24. Efforts on DOTS Expansion, establishing better access to DOTS, are paying off in case detection

25. Incidence: 80-85% level of those
Yes, DOTS is working to reduce S(+) prevalence in Cambodia even with TB/HIV impact. However:
S(+) Prevalence: 50-60% of the WHO estimate and/ or the era before DOTS
Incidence: 80-85% level of those
Detecting S(+) only: Is it enough in community with such a high prevalence, where one out of 11 “grandfathers” is C(+)? : Need to assess unknown impact of chronic S(-)C(+) with a large number of close contacts in a large family in Asia
Incidence of S(-)C(+) may be much higher than the WHO estimate with current model. However, majority of them might not come to health facility to seek treatment because many of them are not so sick.

26. Now, we’ve got a clear view

27. Thanks for your collaboration in advance!
Challenge: The next round in 2008?
Thanks for your collaboration
in advance!
CENAT/JICA National TB Control Project Cambodia