The first National TB Prevalence Survey Rwanda 2012

Transcription

1 The first National TB Prevalence Survey Rwanda 2012 Preliminary Results 29 th April 2013 Patrick Migambi Rwanda Biomedical Centre (RBC)

2 Background Indicator (2011) Population size(census 2012) 10,537,222 GNI per capita (Atlas method) 570 USD Estimated TB Burden (2011) Number Rate Cases (all forms)(surveillance data 2012) 6207 Mortality per 100,000 TB cases with HIV )(surveillance data 2012) Case notifications)(surveillance data 2012) Treatment success)(surveillance data 2012) % per 100, % 2

3 Map of cluster survey 3

4 Methodology

5 Sampling design Sample size: 42,600 Number of clusters: 70 (+3 extra for Kigali) = 73, including 10 clusters for the City of Kigali, 18 for the Southern Province, 17 for the Western, 12 for the Northern and 16 for the Eastern Proportional to Population Size sampling If possible, insert a country map showing the cluster locations <42,600 > <70> clusters <610> people Target 5

6 Selection criteria and health seeking behaviour Inclusion criteria Resident (living for at least 1 month prior to the interview in household) Age of 15 years or above Screening Positive Positive symptom screening is enrolled participant who has cough without duration Abnormal chest x ray is enrolled participant who has any lung abnormality detected on interpretation by the medical officer in the field Health seeking behavior YES Did you consult with someone for help? If yes, where did you go for help? If yes, did you get sputum test, CXR or medicine? 6

7 Laboratory methods Smear: Direct smearing in the field Concentrated smear (and culture) at NRL LED fluorescence microscopy field and NRL Two samples (spot and morning) Smear result available at field site after 24hours Culture media: Lowenstein Jensen (LJ) medium Other: Health center laboratories nearest were used for field laboratory DST was done after identification test by SD Bioline TB ag MPT64 for all MTB culture positive cases HIV testing for all participants eligible for sputum examination No GeneXpert MTB/RIF 7

8 Main Challenges

9 Main challenges of survey implementation Procurement took longer than expected delayed survey start (6-12 months) flexible planning Initially some break down in X-ray trucks preventive maintenance each weekend Backlog QA for lab and CXR high workload extra staff CXR central reading limited capacity radiologist could not visit field field CXR readers met radiologist at central level before each cluster 9

10 RESULTS

11 Participants (preliminary) Total census 83,531 Eligible to participate 44,978 (53.8%) 34,547 (41.4%) children 4,006 (4.8%) non-residents Participants 43,126 (95.9%) 11

12 Eligibility by age group and sex (data for 40 clusters) Percentage eligible (%) Male Female to to to to to Age group (years) 12

13 Participation by age group and sex (40 clusters) 100 Overall participation rate: XX.X% 95 Participation rate (%) Male Female to to to to to Age Group (Years)

14 Participation by cluster Participation rate (%) Cluster number

15 Screening and laboratory investigations (preliminary) Total screened Symptom positive CXR positive Both symptom and CXR positive Screened positive Total specimens obtained Number of participants with lab results 43,126 2,472 (5.2%) 2,566 (5.4%) 329 (0.7%) 4,709 (10.9%) 4,690 (spot) 4,469 (morning) 4,690 15

16 Results of TB Prevalence: Age 15 years* 1) Smear Positive MTB case (N=22): 22 SM+ in 43,126 people surveyed Correlation coefficient of between-cluster variation (k): X.X Design effect: X.X 2) Bacteriologically Confirmed MTB (N=34 definite, 4 no survey cases ): 38 cases in 43,126 people surveyed Correlation coefficient of between-cluster variation (k): X.X Design eff 3) In addition 19 MOTT cases detected (30% of bact pos) 16 *Cluster level analysis (not yet done)

17 Culture confirmed MTB cases by age:

18 Culture confirmed smear positive TB by age and sex: male female

19 Confirmed MTB survey cases: Symptoms and CXR screening results Screening method Smear positive MTB survey cases N=22 Total number of survey cases Percentage of all survey cases Bacteriologically confirmed MTB survey cases N=38 (34 definite, 4 probable) Total number of survey cases Percentage of all survey cases Symptom positive only 1 4.5% % CXR positive only % % Symptom and CXR positive % % 12/40(30%) of MTB survey cases were smear negative 37/40 (92.5%) of MTB survey cases were detected by CXR 17/40(42.5%) of MTB survey cases were detected by symptoms 16/40 (40%) of MTB survey cases should be detected by the current screening strategy in Rwanda criteria: 2 weeks cough] 19

20 Lessons Learnt

21 Major lessons and implications to the NTP What are the main lessons derived from the survey results? Much lower number of cases detected then expected High number of MOTT cases detected (30% of BACT pos) What action is recommended based on the findings? Finalize analysis and indepth investigation of results linked to surveillance data Which cases are not detected routinely? Potential high risk groups? Continue strong program implementation to reduce TB further Investigate high MOTT and provide Tx 21

22 Acknowledgements 22

23 Supplementary slides

24 Laboratory results Total specimens obtained Any smear positive Any culture MTB S+C+ S-C (spot) 4,469(morning) 79 (X.X%) 51 (X.X%) 22 (X.X%) 16 (X.X%) 24

25 Study cases Smear positive MTB cases Bacteriologically confirmed MTB cases Total number of study cases Definite case Probable case 0 0 Possible case none none Number of cases that are smear positive Non-study cases 0 4 ( 4 S-/C+ ) - 22 Definite cases: Probable cases: Possible cases: Non-study cases: 25 CMTB positive with bacteriological confirmation in at least one other sample Culture negative but 1 (or more) samples smear positive and TB confirmed in central CXR (medical panel final decision) NO DEFINITION only bacteriological indication in one sample not confirmed by another sample or central CXR (follow up investigations are conducted), culture results: 4C, 6C, 8C, and 8C, smear results (only 1 LNR positive) 4 barr, 1+ and 1 +

26 Health seeking behaviour Indicator Total number of TB survey cases 40 Number of TB survey cases who were not on treatment at the time of the interview 38 (95%) Number of TB survey cases who were symptomatic 17 (42%) Number of symptomatic TB survey cases not on treatment at the time of the interview 15 (37.5%) Number of TB cases detected by the survey who were already on treatment (Where did they seek care?) 2 (5%) Number of symptomatic TB cases not on treatment but who sought care (Where did they seek care?) 2 at HC, 1 at pharmacy 3/15 (20%) Number of TB survey cases that started on treatment after being detected by the survey Last 3 are currently being put on Tx following medical panel decision last week 37/40 (92%) 26