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Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
Intensified TB case-finding: still wide open to questions and answers
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Intensified TB case-finding: still wide open to questions and answers

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Intensified TB case-finding: still wide open to questions and answers

Intensified TB case-finding: still wide open to questions and answers

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    • 1. Intensified TB case-finding: still wide open to questions and answers Dr Liz Corbett Bloomsbury Wellcome Trust Centre & Clinical Research Unit, London School Hygiene Tropical Medicine Biomedical Research & Training Institute, Harare
    • 2. Pre-DOTS era <ul><li>ICF widely used in all continents </li></ul><ul><ul><li>Mass mini-radiographs and household enquiries </li></ul></ul><ul><ul><li>Diagnosis and treatment +/- sanatoria </li></ul></ul><ul><ul><li>Still used in some settings today </li></ul></ul><ul><li>Use associated with declining TB incidence rates in many settings </li></ul><ul><li>Not formally evaluated as an isolated intervention </li></ul>
    • 3. Kolin <ul><li>1961 – 1972 Kolin study </li></ul><ul><ul><li>5 rounds of MMR </li></ul></ul><ul><ul><li>Point prevalence of s+ TB fell from 233 to 56 per 100k </li></ul></ul><ul><ul><li>Incidence of s+ TB fell from 142 to 52 per 100k per year </li></ul></ul><ul><ul><li>Effective TB treatment introduced + BCG </li></ul></ul><ul><li>72% of all cases detected between MMR rounds through passive CFT </li></ul><ul><li>More effective to focus on effective treatment of cases presenting passively </li></ul>
    • 4. India <ul><li>Tumkur District prevalence survey 1960s (TST and CXR) </li></ul><ul><ul><li>No TB treatment programme </li></ul></ul><ul><li>Follow-up investigation for symptoms (?delay) </li></ul><ul><ul><li>70% of smear-positive patients aware of symptoms </li></ul></ul><ul><ul><li>50% had already sought care </li></ul></ul><ul><li>Bangalore </li></ul><ul><ul><li>CXR versus CXR plus symptom screen </li></ul></ul><ul><ul><ul><li>Symptoms added little to CXR </li></ul></ul></ul><ul><ul><ul><li>Symptoms alone identified 70% culture-positive TB patients </li></ul></ul></ul>Banerji D, Anderson S. A sociological study of awareness of symptoms among persons with pulmonary tuberculosis. Bull Wld Hlth Org 1963; 29:665-683. Gothi GD, et al. Estimation of prevalence of bacillary tuberculosis on basis of chest x-ray and-or symptomatic screening. Indian J Med Res 1976; 64(8):1150-1159.
    • 5. Kenya <ul><li>Case-finding studies in 1970s and 1980s </li></ul><ul><ul><li>House-to-house surveys most effective </li></ul></ul><ul><ul><ul><li>80% of cases had been to clinic with symptoms </li></ul></ul></ul><ul><ul><ul><li>Distance to clinic </li></ul></ul></ul><ul><ul><li>Interview of village elders ineffective </li></ul></ul><ul><ul><li>Mothers asked to refer anyone with symptoms in their household </li></ul></ul><ul><ul><ul><li>High yield in those who attended </li></ul></ul></ul><ul><ul><ul><li>Low population impact (4% all cases) </li></ul></ul></ul>
    • 6. Korea <ul><li>Routine use of “school leavers” for door-to-door enquiry </li></ul><ul><ul><li>Each employee covered 10,000 pop </li></ul></ul><ul><ul><li>Over 50% of cases picked up this way during 1970s </li></ul></ul>
    • 7. Community-wide p reventive therapy: Bethel ARI (%) & incidence rates / 100 000 pop p.a. 0% 5% 10% 15% 20% 25% 30% 1954 1957 1960 1963 1966 1969 1972 500 1,000 1,500 2,000 2,500 3,000 ARI TB incidence Passive & intensified CFT & BCG INH RCT: 42% pop INH 12mos INH all residents
    • 8. Other studies <ul><li>Toman (1976) </li></ul><ul><ul><li>75% of cases self-presenting in countries covered by MMR programmes </li></ul></ul><ul><ul><li>Netherlands – annual CXR (2.5 million adults) </li></ul></ul><ul><ul><ul><li>15% of s+ and 25% of c+ TB detected through MMR </li></ul></ul></ul><ul><ul><li>Expensive, not cost-effective </li></ul></ul><ul><ul><li>Assumes equal public health impact of ACF & PCF pick-up </li></ul></ul>Toman K. Mass radiography in tuberculosis-control. Who Chronicle 1976; 30(2):51-57
    • 9. Fate of pulmonary TB treated under routine conditions <ul><li>High rates of treatment failure and recurrence </li></ul><ul><li>Increasing recognition of the importance of adequate treatment </li></ul><ul><li>First priorities: </li></ul><ul><ul><li>Effective diagnosis in patients presenting passively </li></ul></ul><ul><ul><li>Effective treatment of those presenting passively </li></ul></ul><ul><ul><li>Don’t waste money and risk overwhelming health systems with ICF until these basics are in place  DOTS </li></ul></ul>
    • 10. ICF in the DOTS era <ul><li>Low case-detection a major factor limiting TB control </li></ul><ul><ul><li>Patients with symptoms cannot access investigations </li></ul></ul><ul><ul><li>Marginalised populations </li></ul></ul><ul><ul><li>Not all TB is highly symptomatic </li></ul></ul><ul><li>HIV-associated TB </li></ul><ul><ul><li>Driving up global incidence rates </li></ul></ul><ul><ul><li>High prevalence of active TB in HIV care settings </li></ul></ul><ul><ul><li>High mortality rates </li></ul></ul><ul><li>Modeling the impact of better case-finding </li></ul><ul><li>Time ripe to reconsider ICF </li></ul>
    • 11. ICF goals <ul><li>Reduce morbidity and mortality </li></ul><ul><ul><li>More intensive case-finding leads to fewer TB deaths and less severe post-TB complications </li></ul></ul><ul><ul><li>Focus on those most at risk of severe morbidity </li></ul></ul><ul><li>Reduce TB transmission </li></ul><ul><ul><li>General community </li></ul></ul><ul><ul><li>Institutional settings </li></ul></ul><ul><ul><li>Marginalised populations </li></ul></ul><ul><li>Increase case-finding </li></ul><ul><ul><li>Target high risk groups </li></ul></ul><ul><ul><li>Community-wide approach </li></ul></ul>
    • 12. ICF challenges <ul><li>Poor treatment outcomes </li></ul><ul><ul><li>Patients detected through ICF unwilling to be treated </li></ul></ul><ul><ul><li>ICF in settings of high primary MDR-TB </li></ul></ul><ul><li>Diagnostic approach </li></ul><ul><ul><li>Active versus inactive TB </li></ul></ul><ul><ul><li>Relatively low % smear-positive cases </li></ul></ul><ul><ul><ul><li>Choice of screening and diagnostic tests </li></ul></ul></ul><ul><ul><li>Illnesses other than TB </li></ul></ul><ul><ul><ul><li>OIs & HIV itself </li></ul></ul></ul><ul><li>Overwhelm the health system </li></ul>
    • 13. Cohort study Prevalence study snap shot in time Time (person years) Incidence and prevalence linked by duration of disease
    • 14. Prevalent TB disease <ul><li>High ratio of prevalent: incident disease among HIV-ves </li></ul><ul><ul><li>See next slide </li></ul></ul><ul><li>Risk groups for prevalent TB disease </li></ul><ul><ul><li>Household contacts </li></ul></ul><ul><ul><li>Homeless </li></ul></ul><ul><ul><li>IDU </li></ul></ul><ul><ul><li>VCT attenders </li></ul></ul><ul><ul><li>Home based care </li></ul></ul><ul><ul><li>Congregate settings: prisons and miners </li></ul></ul><ul><ul><li>Old age and male sex </li></ul></ul>
    • 15. Prevalence: incidence
    • 16. Can have prolonged HIV/TB with minimal symptoms: duration of smr+ before diagnosis
    • 17. What do we need to know? <ul><li>ICF in high HIV prevalence populations </li></ul><ul><ul><li>Screening algorithms </li></ul></ul><ul><ul><ul><li>Expect these to vary by HIV status </li></ul></ul></ul><ul><ul><ul><li>Expect these to vary by effectiveness of DOTS </li></ul></ul></ul><ul><ul><li>Can ICF substantially improve TB control? </li></ul></ul><ul><li>ICF and treatment outcomes </li></ul><ul><ul><li>High and low MDR-TB settings </li></ul></ul><ul><ul><li>IDU </li></ul></ul><ul><li>Better understanding of prevalent TB disease </li></ul><ul><ul><li>Impact of HIV </li></ul></ul><ul><ul><li>Why is prevalent TB so common in HIV-ve pops? </li></ul></ul><ul><ul><li>Does IPT increase risk of prolonged TB excretion </li></ul></ul>
    • 18. What do we need to know? <ul><li>Targeted ICF: how to do it better </li></ul><ul><ul><li>Strategies to reach high risk populations (Tables1 & 2) </li></ul></ul><ul><ul><ul><li>High risk of TB morbidity </li></ul></ul></ul><ul><ul><ul><li>High risk of prevalent active TB </li></ul></ul></ul><ul><ul><li>Strategies accessible by the general population </li></ul></ul><ul><ul><ul><li>ZAMSTAR </li></ul></ul></ul><ul><ul><ul><li>TB screening clinics akin to VCT clinics </li></ul></ul></ul><ul><ul><ul><li>TB screening clinics accessible only on referral </li></ul></ul></ul><ul><ul><li>Involving the community </li></ul></ul><ul><ul><ul><li>TB clubs / shop keepers / home based care </li></ul></ul></ul><ul><ul><li>Linked to better management of smear-negative TB </li></ul></ul>
    • 19. Institutional TB <ul><li>How much TB is institutionally acquired? </li></ul><ul><ul><li>TST conversion in student nurses </li></ul></ul><ul><ul><ul><li>18% p.a. strict US criteria after negative 2-step in Harare </li></ul></ul></ul><ul><ul><ul><ul><li>Will have parallel ELISPOT data </li></ul></ul></ul></ul><ul><ul><ul><li>? 10+% annual risk of TB disease if HIV+ve </li></ul></ul></ul><ul><ul><li>HIV care patients </li></ul></ul><ul><ul><ul><li>Recurrent TB disease in patients on ARVs </li></ul></ul></ul><ul><ul><ul><li>Gold miners: </li></ul></ul></ul><ul><ul><ul><ul><li>recurrent TB increased from ~8% p.a to ~25% p.a. in HIV+ </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Coincided with introduction of HIV care clinic </li></ul></ul></ul></ul><ul><li>Can ICF control institutional TB transmission? </li></ul><ul><ul><li>Long term preventive therapy? </li></ul></ul><ul><ul><li>Role of culture-based ICF </li></ul></ul>
    • 20. Ongoing research <ul><li>Shop keepers: Malawi </li></ul><ul><li>ZAMSTAR </li></ul><ul><li>DETECTB </li></ul><ul><li>Cambodia </li></ul><ul><li>Kenya </li></ul><ul><li>Others? </li></ul><ul><li>Institutional TB: ARTI in student nurses </li></ul><ul><ul><li>Others? </li></ul></ul>
    • 21. Recommended priority groups for targeted ICF <ul><li>VCT clients </li></ul><ul><li>HIV care clinics </li></ul><ul><li>Patients starting ARVs (IRIS) </li></ul><ul><li>Household contacts </li></ul><ul><li>IVDU </li></ul><ul><li>Institutions </li></ul><ul><ul><li>Prisons </li></ul></ul><ul><ul><li>hospitals </li></ul></ul>
    • 22. General population screening <ul><li>Insufficient evidence on which to base recommendations </li></ul><ul><ul><li>Potential HUGE: true TB prevention </li></ul></ul><ul><ul><li>Impact of a single round or brief period of highly effective population-based ICF? </li></ul></ul><ul><ul><ul><li>DOTS can be the sustainable element (Bethel0 </li></ul></ul></ul><ul><ul><ul><li>One passive = one ICF patient? </li></ul></ul></ul><ul><ul><ul><li>Respective roles of reactivation and recent TB infection </li></ul></ul></ul><ul><li>Effective screening tool: digital MMR?? </li></ul><ul><li>Effective diagnostic test </li></ul><ul><li>Effective case-management </li></ul><ul><ul><li>Note that in high HIV prevalence settings the ratio of prevalent to incident cases may not be all that high </li></ul></ul><ul><ul><li>Would expect a rapid impact on new TB cases if prevalent TB disease control is improved </li></ul></ul>
    • 23. Conclusions <ul><li>ICF is natural extension of DOTS </li></ul><ul><ul><li>Operational research priorities & interim recommendations – p 7 </li></ul></ul><ul><ul><li>Targeted linked to IPT and ARVS </li></ul></ul><ul><ul><ul><li>VCT clients </li></ul></ul></ul><ul><ul><ul><li>Institutional TB control </li></ul></ul></ul><ul><ul><ul><li>Household contact screening </li></ul></ul></ul><ul><ul><ul><li>IDUs </li></ul></ul></ul><ul><ul><li>General populations: model / demonstration programmes? </li></ul></ul><ul><ul><ul><li>TB screening clinics </li></ul></ul></ul><ul><ul><ul><li>Shop-keepers </li></ul></ul></ul><ul><ul><ul><li>ZAMSTAR approach </li></ul></ul></ul><ul><ul><ul><li>Household screening </li></ul></ul></ul><ul><ul><ul><li>MMRs </li></ul></ul></ul><ul><li>TB case-finding is HIV case finding </li></ul><ul><ul><li>Chronic cough patients in Harare </li></ul></ul><ul><ul><ul><li>HIV prevalence 83% overall: 88% in TB patients </li></ul></ul></ul>

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