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Haileyesus GetahunStop TB Department
WHO
Intensified TB case finding among people living with HIV: what are the
challenges of current strategies?
13th TB/HIV Core Group Meeting, April 17-18, 2008, New York, USA
Outline of presentation
• Global implementation of TB case finding
• Examples of country screening strategies
• Review of evidence on screening strategies
• Challenges
• Conclusions
The boundaries and names shown and the designations used on this map do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.
Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. WHO 2006. All rights reserved
Countries with policy on intensified TB case finding among PLHIV, 2006 (N=109)
No policy on ICF
With policy on ICF
Key
Countries reported TB screening among PLHIV, 2006 (N= 44)
The boundaries and names shown and the designations used on this map do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.
Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. WHO 2006. All rights reserved
No reported activity
Countries reporting ICF
Key
* Brazil did not report for 2006
• 0.96% of PLHIV are screened for TB globally• South Africa and Russia report 68% of the screened PLHIV
Percentage of PLHIV screened for TB in countries with 80% of the global burden,
2006.1.83
0.00
0.77
0.00 0.00 0.05 0.00
1.07
0.00 0.00
0.31
0.00
0.78
0.96
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2.00
Proportion of PLHIV screened and diagnosed with TB in selected
countries, 2006
0
20,000
40,000
60,000
80,000
100,000
120,000
South Africa Mozambique India Ethiopia Rwanda
PLHIV screened for TB
PLHIV with TB after screening
29%
8%20% 31% 72%
Examples of TB screening tool from countries
National screening strategy: Rwanda
3-6 months
National screening strategy: Kenya
Symptoms and signsAdults (any of)
1. Cough (of any duration)?2. Blood stained sputum?3. Night sweats >2 weeks4. Fever ?5. Weight loss?6. Chest pain?7. Breathlessness?8. Fatigue?9. History of previous TB
treatment?10. History of close contact with a
person confirmed to have TB? 11. Swellings in the neck, armpits
or elsewhere?12: Diarrhea for more than two
weeks?
Symptom and signsChildren (any of)
1. Cough: (of any duration)? 2. Blood stained sputum?3. Night sweats >2 weeks4. Fever? Of any duration?5. Weight loss?6. Chest pain?7. Fast Breathing?8. Fatigue?9. History of previous TB
treatment?10. History of close contact with a
person confirmed to have TB? 11. Swellings in the neck, armpits
or elsewhere?12: Diarrhea for more than 2
weeks?13. Failure to thrive?
National screening strategy: India
If any of the symptoms:• Cough of 2wks and/or household contact with TB patient• Hemoptysis• Fever• Excessive fatigue/night sweats/loss of apetite• Pleuritic chest pain (increasing on cough/deep breathing)• Swelling in the neck, arm pit, groin, abdomen, joints etc
National screening strategy: Tanzania
Do you have the following?(one or more)1. Cough for 2 or more
wks?2. Hemoptysis?3. Fever for 2 or more
wks?4. Noticeable wt loss for
new patients or a 3kg loss in a month?
5. Excessive sweating at night for 2 or more wks?
Every month
National screening strategy: Malawi
Any of the following
• Cough more than 3wks• Weight loss• Fever or night sweats• Fatigue/tiredness• Loss of appetite • Lymph node enlargement
Observations from country practice
• Screening tools vary from country to country
• More and more non-specific constitutional symptoms and signs included in tools
• Children are not addressed
• Presence of nationally recommended screening tool does not always guarantee implementation
Review of the published evidence of TB screening strategies
Kimerling, et.al – Cambodia,2002
IJTLD 2002; 6:988–994
Population
441 HIV+ in home-based care
Gold stn. Single sputum culture
# with TB
41 (9%) with culture-confirmed TB
Cough Cough >3 weeks 65% sensitive, 33% specific
Algorithm
Any 1 of: - cough>3 wks - hemoptysis - weight loss - fever - night sweats - weakness No information on role of CXR
Sensitivity= 95%Specificity= 10%
Mohammed, et.al. – South Africa, 2004
IJTLD 2004: 8:792-795
Population
129 HIV+ referred for IPT
Gold stn. Definite = cx confirmed, probable = smear+, possible = clinical dx with response to treatment
# with TB
11 (9%) with TB (10 culture-confirmed)
Cough Cough >2 weeks 82% sensitive, 79% specific
Algorithm
2 or more of: - weight loss (>2.5%) - cough - night sweats - feverAdding CXR didn't improve performance
Sensitivity= 100%Specificity= 88%
Day, et. al. – South Africa, 2006IJTLD 2006: 10:523-529
Population 899 HIV-infected miners being evaluated for IPT
Gold Stn. Culture positive or clinical improvement
# with TB 44 (5%) patients met definition for TB, 35 culture +
Cough Cough >3 weeks 14% sensitive, 88% specific
Algorithm • Any 1 of - night sweats
- new or worsening cough - weight loss >5%
- abnormal CXR. • Combination of - night sweats
- cough - reported weight loss
CXR increased the sensitivity of the screening
Sensitivity= 91%Specificity= 59%
Sensitivity= 59%Specificity= 76%
Chheng, et.al. – Cambodia,2008 IJTLD 2008: 12: S54-S62
Population 496 HIV+ and HIV- at VCT centre (124 HIV+)
Gold Stn. Sputum culture
# with TB 29 (6%) with culture-confirmed TB
Cough Cough >3 weeks 55% sensitive, 59% specific
Algorithm • Any 1 of: - hemoptysis - fever - weight loss - loss of appetite - night sweats • Complex of: - fever - hemoptysis - weight loss • BMI <18.5: Sensitivity 70%, specificity 61%• No CXR was performed
Sensitivity= 100%Specificity= 19%
Sensitivity= 100%Specificity= 20%
Demissie, et.al. – EthiopiaWorld Lung Health Conference 2007 Abstract S11
Setting Addis Ababa, Ethiopia – community hospital
Study pop.
438 newly diagnosed HIV+
Gold Stn. Concentrated sputum smear and culture
# with TB 32 (7%) with culture-confirmed TB
Cough Cough> 2 wks is 44% sensitive, 76% specific
Algorithm Cough or fever – 75% sensitivity, 57% specificityCXR improved sensitivity to 91% (at a cost of specificity)
Cain, et.al.Thailand, Cambodia, 2008
World Lung Health Conference 2007 Abstract S11
Study Pop.
951 newly diagnosed or newly presenting HIV +
TB defin Culture positive
# with TB 66 (7%) with culture-confirmed TB
Cough Any (71% sensitivity, 56% specificity)More than 2 wks (29% sensitive, 85% specific)More than 3 wks (24% sensitive, 91% specific)
Algorithm Any 1 of: - cough - fever - weight lossOther symptoms: Loss of appetite, weight loss, difficulty breathing, fatigue, fever, shaking chills, night sweat, chest pain, abdominal pain,nausea / vomiting
Sensitivity= 91%Specificity= 33%
Recalculation on the published algorithms
using Thailand and Cambodia data (Courteousy of Cain & Varma, 2008)
Algorithm Sensitivity Specificity
Day (cough, NS, wt. loss) 86 (59*) 34 (76)
Mohammed (any 2 of: cough, NS, fever, wt. loss >2.5%)
74 (100) 61 (88)
Kimerling (any 1 of cough >3 wks, hemoptysis, wt. loss, fever, NS, weakness)
82 (100) 45 (10)
Chheng (hemoptysis, wt. loss, fever)
82 (100) 47 (20)
Demissie (cough or fever) 89 (75) 43 (57)* In Blue are original figures
Algorithm CD4 < 250 CD4 >250
Sensitivity
Specificity
Sensitivity
Specificity
Day 97 31 70 39
Mohammed
92 51 48 67
Kimerling 92 35 67 54
Demissie 95 37 81 47
Pre-IPT 92 51 52 64
Cough/fever/wt. loss
97 27 81 37
Recalculation of published algorithms using Thailand and Cambodia data (Courteousy of Cain & Varma,2008)
Observations from available evidence
• Findings are generally inconsistent
• Chronic cough more than 2 or 3 wks alone looks insensitive predictor of TB in PLHIV
• Role of CXR is not clear and inconsistent
Challenges: "Sub-clinical" TB in
PLHIV
• Lucas et al. AIDS 1991 (Cote D’Ivoire)
• Mtei et al. Clin Infect Dis 2004 (Tanzania)
• Day et al. Int J Tuberc Lung Dis 2006 (S. Africa)
• Wood et al. AJRCCM 2007 (S. Africa)
• Corbett et al. PLoS Med 2007 (Zimbabwe)
Challenge: implementation issues
• Standardised screening tool needed but is there enough evidence to develop an optimal one?
• Screening tool that can rule out active TB disease is needed and how best to link it with IPT?
• Who administers the standard tool and where?
• How often should it be administered?
• Monitoring and evaluation- how should it be recorded and reported?
Conclusions
• TB screening among PLHIV is poorly implemented and requires urgent action
• Standardised screening tool is needed but there is no complete evidence to develop one
• Massive research efforts to develop the best and feasible screening tool are urgently needed
• Interim tool through meta-analysis of existing data need to be explored through collaboration
• "TB dipstick test"- simple and rapid tool is crucial