The 3rd National TB Prevalence Survey Non-Bangkok clusters in Thailand

in 2012 Preliminary Results

29th April 2013

Chawetsan Namwat, MD, Director of TB Bureau

Sriprapa Nateniyom, MD, Senior medical doctor in preventive medicine

Sirinapha Jittimanee, PhD, Public Health Officer

Department of Disease Control, Ministry of Public Health

2 |

Background

Indicator (2011) Population size 70 million GNI per capita (Atlas method) 4,400 ($US)

Estimated TB Burden (2011)

Number Rate

Cases (all forms) 76,000 N/A Mortality 9,800 14 per 100,000 TB cases with HIV 15 % N/A Case notifications 67,676 97 per 100,000 Treatment success 41,451 61 %

3 | 3 Methodology

4 |

90,000 Target

100 clusters 900 people

Sampling design Sample size: 76,331 Number of clusters: 100 Sampling method:

Stratified multi-stage cluster sampling, stratified by area (Bangkok, urban outside Bangkok, rural outside Bangkok)

5 |

Selection criteria and health seeking behaviour

Inclusion criteria Aged 15 years or more

Slept in the clusters 14 days or more

Screening Positive Clinical score > 3

Abnormal CXR

Health seeking behavior Each cluster, 3 participants with screening positive were interviewed their health seeking behavior.

6 |

Laboratory methods Smear:

Direct smear Ziehl-Neelsen staining Two samples (one spot and one early morning)

Culture media: Modified (2%) Ogawa method Two samples (one spot and one early morning)

Other: One lab for preparation for reagent staining and media for culture

and 12 DDC lab for smear and culture and identification No GeneXpert MTB/RIF No Drug sensitivity testing of positive samples No HIV testing of participants or survey patients

Main Challenges

8 |

Main challenges of survey implementation

Low participation rates in urban clusters due to annual CXR check-up for employment, not staying at home during census, middle to high income communities.

There were 12 survey teams and each one had limited experience on the first-second clusters. However, the team members were familiar with communities.

Most of budget was from the GF which requested a lot of supporting documents for payment, i.e Non-registered migrants declined due to lack of the ID numbers/ work permits.

RESULTS

10 |

CXR+ and/or Symptom+ = 6,032 (9.8%)

Smear Neg = 5,926

Smear Pos =75

CMTB=

84

CON 196

NTM 20

C Neg 5,626

Definite = 130

C Neg=23

CMTB =

46

No TB

13

TB consistent 10

CON = 1

NTM=5

TB consistent

1

TB consistent 1 (on TB Tx)

No TB 4

Probable = 12

CXR CXR

NA = 31 (missing sputum sample 1 & 2)

Eligible = 78,647

Participants = 61,653 (78%)

Non-Participants = 17,098 (22%)

Screening neg. 55,552 (90%)

Preliminary results of 83 Non-Bangkok

clusters in 2012

11 |

Participants

•78,680 Total census

•78,647 (99.96%) Eligible to participate

•61,653 (78.39%) Participants

12 |

Eligibility by age group and sex

99.84 99.91 99.93

100.00 99.97 99.96 99.96 99.95 99.98 99.97 99.99 100.00

99.00

99.20

99.40

99.60

99.80

100.00

100.20

100.40

15 to 24 25 to 34 35 to 44 45 to 54 55 to 64 65+

Perc

enta

ge e

ligib

le (%

)

Age group (years)

Eligibility by age group and gender

MaleFemale

13 |

Participation by age group and sex

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

15 to 24 25 to 34 35 to 44 45 to 54 55 to 64 65+

Part

icip

atio

n ra

te

Age Group (Years)

Participation by age group and sex

Male

Female

Overall participation rate: 78.4%

14 |

Participation by cluster

0

10

20

30

40

50

60

70

80

90

100

9 77 46 10 25 11 47 19 12 35 5 36 13 33 6 34 14 37 7 38 20 63 1 54 15 55 2 31 8 53 22 56 3 57 40 4 67 68 44 69 60 62

Part

icip

atio

n ra

te (%

)

Cluster number

Participation rate by cluster (chronological order)

15 |

0

10

20

30

40

50

60

70

80

90

100

9 18 11 80 5 50 83 30 1 56 66 3 44 72 60

Part

icip

atio

n ra

te (%

)

Cluster number

Participation rate by URBAN clusters (chronological order)

16 |

0

10

20

30

40

50

60

70

80

90

100

45 17 78 25 24 19 12 35 27 81 49 82 34 14 37 38 20 63 52 64 29 59 21 58 16 65 32 57 40 4 67 68 69 61

Part

icip

atio

n ra

te (%

)

Cluster number

Participation rate by URBAN clusters (chronological order)

17 |

Screening and laboratory investigations

• 61,653 Total screened

• NA Symptom positive

• 5,963 (9.7%) CXR positive

• NA Both symptom and CXR positive

• 6,032 (9.8%) Screened positive

• 5,993 (spot) 5,741 (morning) Total specimens obtained

• 6,001 Number of participants with lab results

Spot Morning missing = 39 Missing =

291

18 |

Results of TB Prevalence: Age ≥15 years*

Smear Positive MTB case (n=58):

Bacteriologically Confirmed MTB (n=142):

19 |

Confirmed MTB survey cases: Symptoms and CXR screening results

Screening method Smear positive MTB

survey cases, n=58 Bacteriologically confirmed MTB

survey cases, n=142 Total number of

survey cases Percentage of all

survey cases Total number of

survey cases Percentage of all

survey cases

Symptom positive only 1 2% 5 4% CXR positive only 30 52% 95 67% Symptom and CXR positive 27 47% 42 30% What proportion of MTB survey cases were smear negative? => 84/142 = 59% What proportion of MTB survey cases were detected by CXR? => 95/142 = 67% What proportion of MTB survey cases were detected by symptoms? => 5/142 = 4% What proportion of MTB survey cases would have been detected by the current screening strategy in your country? => 42/142 = 30%

20 |

Laboratory results • 5,993 (spot) 5,741 (morning) Total specimens

obtained

•78 cases , 116 samples Any smear positive

•133 cases, 181 samples Any culture MTB

•46 cases, 75 samples S+C+

•84 cases, 106 samples S-C+

21 |

Study cases Smear positive

MTB cases

Bacteriologically confirmed MTB cases

Total number of study cases 58

142

Definite case 46

130

Probable case 12

12

Possible case- No study case (SM+ without other evidence/ or scanty C-MTB+ without other evidence)

(13) (0)

Non-study cases (NTM) (4)

(24)

Number of subjects that are smear positive

75 -

Definite cases: Culture positive with AFB+ or abnormal CXR Probable cases: SM+ and CXR abnormal and culture no growth Possible cases: SM+ (scanty) with symptom, CXR normal, Culture not MTB positive inc. MOTT/NTM Non-study cases: SM+, NTM,

22 |

Number of bacteriologically-positive detected cases by the survey by age and sex (n = 142)

23 |

Prevalence survey – provisional result, Thai- non-Bangkok (/100 000 participants aged 15y or older)

PENDING

24 |

Prevalence of TB – Provisional Results of Non-Bangkok

PENDING

25 |

Next steps Data entry and data analysis for non-BKK clusters (n=83) Data collection for BKK clusters (n=17) Report writing

26 |

Acknowledgements