TB: The Coventry perspective

1. TB: The Coventry perspective Dr Thekli Gee University Hospitals Coventry & Warwickshire

2. Outline TB in Coventry: • Epidemiology • Resources • New diagnostic approaches

3. Epidemiology

4. Occurrence • Nearly a third of the world’s population is infected with TB • TB kills almost 3 million people per year.

5. chemotherapy BCG vaccination Tuberculosis notifications England & Wales 1913 - 2006 Source: Statutory Notifications of Infectious Diseases (NOIDs)

6. Coventry 2007 Rate per 100,000 population 35 30 25 20 Coventry PCT West Midlands rate England & Wales Linear (Coventry PCT) 15 10 5 0 1999 2000 2001 2002 2003 2004 2005 2006 Coventry TB rate by year 1999-2006

7. Coventry 2007 Tuberculosis case reports and rates by region/country, England, Wales and Northern Ireland, 2006

8. Coventry

9. Why Is TB Increasing?

10. Why Is TB Increasing? Multiple contributing factors: • Homelessness • Intravenous drug use • HIV infection • Drug-resistant strains of TB • Reduced TB control and treatment resources • Immigration from high TB prevalence areas

11. Tuberculosis case reports by place of birth and ethnic group, England, Wales and Northern Ireland, 2001 - 2006

12. Changing populations • Coventry City council • 1215 asylum seekers on housing list • Coventry refugee centre • 8000 asylum seekers & refugees registered • 1571 registered at Meridian Health Centre

13. Afghanistan Iraq Iran Burundi Democratic Republic of Congo Ethiopia Eritrea Somalia Sudan Zimbabwe Changing populations

14. Resources Increasing numbers of TB cases  Increased demand on TB services

15. Impact on resources • Hospital & community TB services • TB clinic • TB nurse time • Infection control • Isolation facilities • TB incidents • Occupational health • Pre-employment screening • HCW contacts • Laboratory services

16. Impact on resources • Hospital & community TB services • TB clinic • TB nurse time • Infection control • Isolation facilities • TB incidents • Occupational health • Pre-employment screening • HCW contacts • Laboratory services

17. 23 incidents in since January 2007 18 Patients Not isolated early enough / at all during admission Mostly medical wards 2 Cardiothoracic ward 1 haematology day unit 5 Health care workers 3 qualified nurses 1 nursing student Ward host TB incidents at UHCW NHS Trust

18. 2007 Impact on resources • Hospital & community TB services • TB clinic • TB nurse time • Infection control • TB incidents • Isolation facilities • Occupational health • Pre-employment screening • Annual reminders • HCW contacts • Laboratory services

19. 2006 Impact on resources • Hospital & community TB services • TB clinic • TB nurse time • Infection control • TB incidents • Isolation facilities • Occupational health • Pre-employment screening • Annual reminders • HCW contacts • Laboratory services

20. 2004 2007 2006 2007 TB national strategy

21. Controlling TB: • Diagnosing primary cases • Treating active disease • Preventing transmission • Identifying secondary cases • Controlling latent infection

22. Current diagnostic test for latent TB • Diagnosis of latent TB relies on the tuberculin skin test. • 101 years old • Developed 1907 by Charles Mantoux • The oldest diagnostic test still in use. The skin test enters its 6th decade of use. (Canada 1957)

23. 48-72 hours later • No longer available Tuberculin skin tests • Mantoux test • Heaf test

24. Tuberculin skin tests • Poor specificity: • antigenic cross-reactivity • BCG • environmental mycobacteria • Poor sensitivity: • 75-90% in active disease • lower in disseminated TB and HIV infection • Need for return visit • 50% DNA rate • Operator variability • inoculation & reading • Painful inflammation & scarring • Boosting effect if used repeatedly

25. New approaches

26. TB Interferon-g release assays(TIGRA) • Principle of TIGRA • Detect IFN-g produced by effector T-cells that recognise M. tuberculosis proteins ESAT-6 & CFP-10 • Absent in BCG • Absent in most non-tuberculous Mycobacteria • Exceptions: M. marinum, M. kansasii

27. T-Spot.TB® Detects individual effector T-cells that produce IFN-g in response to M.tuberculosis antigens Enzyme linked immunospot technique (ELISPOT). QuantiFERON Gold® Measures IFN-g in the supernatant of the antigen stimulated cells Enzyme linked immunosorbant assay technique (ELISA) Two Tests available

32. Method - T-Spot.TB® • Specimens must be processed within 8 hours of venepuncture

34. ELISPOT -ve +ve

35. ELISPOT Reader

36. Role of TIGRAs • Detection of latent TB: • TB contacts • Healthcare workers • New employment screens • Following TB exposure incidents • Before starting immunosuppression • anti-TNF-α drugs e.g infliximab • Pre-transplantation • Detection of active extra-pulmonary TB • If difficult to diagnose by conventional methods • Closely competing diagnoses e.g. Sarcoid vs TB

37. Contact tracing:When to use a TIGRA • NICE: • Following positive Mantoux test • Most cost effective • May miss some cases • CDC • In place of Mantoux test • Shifts burden of work from TB nurses to lab

38. Business case • Laboratory service • 5 day to 6 day service • Warwickshire wide (Network) • TIGRA • Tspot.TB • Microbiology / Immunology

39. Summary • TB increasing in Coventry • Increased demand on resources • New approaches considered • e.g. TIGRAs