Systematic TB screening: Operational
research - Enhanced contact
investigation of smear-positive
tuberculosis patients in Mongolia
J. Narantuya, Technical officer on HIV, AIDS, STIs,
Tuberculosis and Hepatitis, WHO Mongolia
The ninth Technical Advisory Group and National TB
Managers meeting
Manila, Philippines
9-12 December 2014
CONTENT
•
•
•
•
•
•
•
Background
Objectives
Methods
Implementation
Preliminary results
Policy implications and future directions
Acknowledgement
BACKGROUND
• Prevalence of TB in 2013 (includes HIV+TB)
254 per 100,00 population (Global TB report,
WHO 2014)
• Current practice is passive contact
investigation
• Contact investigation form is not used
OBJECTIVES
1. General objective
• To assess impact of enhanced contact investigation through introduction of
active home-visit and new recording and reporting forms in Ulaanbaatar,
Mongolia
2. Specific objectives
 To describe screening coverage of household TB contacts
 To determine prevalence of TB disease and latent TB infection among
household contacts
 To determine secondary attack rate of pulmonary TB among household
contacts
 To identify risk factors for TB disease and latent TB infection among
household contacts
 To develop standard operating procedures (SOPs) for contact investigation
METHODS
• Study design
– Cluster randomized control trial
• Study area and population
– 8 districts of Ulaanbaatar city (capital) have been
selected randomly: 4 intervention and 4 control
districts
– Target population: New smear positive pulmonary TB
patients who are diagnosed and notified at district TB
dispensary and their contacts
– 460 index cases and 1536 contacts were planned
METHODS
• Eligibility criteria
– Newly diagnosed smear-positive TB patients
– A household contact is defined as any person staying in the
same household with index case for more than 3 months
before the date of diagnosis of index cases
– Informed consent
• Excluding criteria:
– index patients who are less than 15 years of age;
– index patients who have a history of TB in the family
– index cases who have no household contact (living alone).
IMPLEMENTATION
IMPLEMENTATION
• Training of health providers
• Advocacy meetings with district health authorities
• Newly developed individual contact investigation
form
• Questionnaires:
– For index case
– For household
– For contacts
• Diagnostic tools:
– Sputum smear microscopy
– Tuberculin skin test
– X-ray
PRELIMINARY RESULTS: Index
cases and contacts
Male 278 (55.7%)
80
60
0
20
• Housing
40
•
Number
Index (N=499)
• All smear-positive cases
> 15 years in 8 districts
100
Age distribution of smear−positive index cases
– House 157 (31.4%)
– Apartment 149 (29.8%)
– Ger 172 (34.4%)
15−19
20−29
30−39
40−49
50−59
60+
Age group
150
100
50
0
Number
Contacts (N=1437)
• Average 3.8 per index
• Male 632 (44.0%)
200
Age distribution of contacts screened
<05
05−14
15−24
25−34
35−44
Age group
45−54
55−64
65+
Yield
by (contact)
age
group
Yield of contact
investigation,
by contact
age group
15
●
●
All forms
Smear−positive
●
10.2 %
Yield (%)
10
●
5
●
●
●
●
0.9 %
●
0
<05
05−14
Children
15−24
●
●
2.5 %
●
●
●
25−34
Age group Adults
35−44
45+
1.0 %
Risk factors (determinants of yield)
Risk factor analysis
• Index factors
• Household factors
• Individual factors
Index factors
(preliminary)
• Index aged 30-49
• Unemployed
• Cough > 8 weeks
• X-ray cavity
Variable
Age group
15-19
20-29
30-39
40-49
50+
Sex
Female
Male
Occupation
Salaried
Self-employed
Student
Unemployed
Others
Cough
No cough
<2 weeks
2-7 weeks
>8 weeks
Smear grade
Few ~ 1+
2+
3+
Xray cavity
No
Yes
Confirmed TB
Total Case % 95% CI
p
OR
Odds Ratio
95% CI
p
210
464
314
214
224
5 2.33 (1.00-5.33) 0.001 **
19 3.93 (2.53-6.06)
28 8.19 (5.72-11.58)
14 6.14 (3.69-10.04)
5 2.18 (0.94-5.01)
1.00
1.75 (0.69-5.34) 0.272
4.01 (1.66-11.97) 0.005 **
2.87 (1.08-9.01) 0.047 *
0.94 (0.26-3.41) 0.918
669
751
38 5.37 (3.94-7.29) 0.275
33 4.21 (3.01-5.85)
1.00
0.76 (0.47-1.23) 0.268
375
167
265
372
247
15 3.85 (2.34-6.25) 0.167
8 4.57 (2.33-8.76)
10 3.64 (1.99-6.56)
28 7.00 (4.89-9.93)
10 3.89 (2.13-7.01)
1.00
1.21 (0.48-2.84)
0.94 (0.40-2.11)
1.95 (1.04-3.81)
1.01 (0.43-2.27)
170
155
655
444
3 1.73 (0.59-4.97) 0.078
5 3.12 (1.34-7.11)
35 5.07 (3.67-6.97)
28 5.93 (4.14-8.44)
1.00
1.86 (0.45-9.17) 0.403
3.14 (1.11-13.15) 0.060
3.75 (1.31-15.82) 0.032 *
790
299
337
31 3.78 (2.67-5.31) 0.111
19 5.97 (3.86-9.14)
21 5.87 (3.87-8.80)
1.00
1.66 (0.91-2.96) 0.090
1.63 (0.91-2.86) 0.094
959
467
40 4.00 (2.95-5.41) 0.051
31 6.22 (4.42-8.70)
1.00
1.63 (1.00-2.64) 0.046 *
0.674
0.884
0.042 *
0.976
POLICY IMPLICATIONS and
FUTURE DIRECTIONS
• Include active contact investigation in the national
guidelines
• Introduce new contact investigation form and use it by
health providers
• Involve primary health providers and social workers
• Consider to implement active contact investigation
• Strengthen collaboration between:
– Primary health care providers (Family group practice)
– District TB dispensaries
– Local governors’ office
ACKNOWLEDGEMENT
•
•
•
•
Dr Gantungalag, National TB Programme
Dr Nobuyuki Nishikiori, STB, WPRO
Dr Fukushi Morishita, STC
TB surveillance and research department,
NCCD
• District health departments in Ulaanbaatar
• TB doctors at the district TB dispensaries
• Primary health care providers (FGPs) in
selected districts
THANK YOU!