Tuberculosis

1. Tuberculosis Dr. Pracheth R.

2. Outline • Problem statement • Epidemiology • Control

4. Problem statement • Most new cases: developing countries • India: highest TB burden • 1/4th of global cases • Prevalence: 256, Incidence: 126/10,000 • 17%: of all communicable disease deaths • People: 15-54 years • Kills more women : reproductive age group

5. Epidemiological indices • Prevalence of infection • Incidence of infection • Prevalence of disease/case rate • Incidence of new cases: per 1,000 • Prevalence of suspect cases • Case detection rate • Prevalence of drug resistant cases

6. Definitions • Case • Smear positive ,negative TB • New case: <4 weeks • Relapse • Failure: 5 months or more • Return after default : 2 months • Cured: Smear positive, negative smear: 2 occasions (1 on treatment completion)

7. Agent factors • Agent: • Facultative intracellular • Human and bovine strain • Atypical mycobacteria • Source of infection: • Human: 1 case-10 to 15 persons • Bovine: milk • Communicability: infective-untreated

8. Host factors • Age: childhood-adolescence • Sex: males • Malnutrition • Immunity

9. Social factors • Poor quality of life • Overcrowding • Population explosion • Undernutrition • Lack of education • Ignorance • Large families

10. Mode of transmission

11. Incubation period • Receipt of infection to positive tuberculin test: 3-6 weeks • Development of disease: • Closeness of contact • Extent of disease • Sputum positivity of case

12. Clinical features • Cough. • Weight loss/anorexia. • Fever. • Night sweats. • Hemoptysis. • Chest pain. • Fatigue

13. TB Control • WHO: prevalence of natural infection in 0-14 years-1 % • Curative: Case finding and treatment • Preventive: BCG vaccination

14. Sputum examination • Sputum Examination: • 2 samples • Early morning- secretions build up overnight • Day1- Sample 1- on the spot - sputum container given • Day 2- Sample 2- brings early morning sample

15. Technique • Inhale deeply 2-3 times • Cough deeply from chest • Open container, bring close to mouth, bring sputum out into it • No saliva/ nasal secretion given; close container • Open space • Empty bowel, bladder before starting

17. Advantages of sputum microscopy • More reliable • Simple • Minimal infrastructure • Inexpensive, quick results • To monitor patient progress , declare the patient “ cured”.

18. Ziehl-Neelson

19. Continued…. • Disadvantages: • At least 10,000 bacilli per ml • False positive: • Red stain- scratches on slide • Accidental transfer of AFBs • Environmental mycobacteria • Various acid fast particles (food particles)

20. Continued…. • False negative: • Problems in collecting • Inadequate sample • Inappropriate sputum container • Sputum stored too long before microscopy • Processing • Faulty sampling of sputum, smear preparation, staining.

21. Continued… • Misinterpreting sputum smears: • Inadequate time in examining • Inadequate attention • Administrative errors: • Misidentification of patients • Incorrect labeling of sample • Documentation errors

22. Other tests • Fluorescence microscopy: • Auramine stain, field of view: 10 times • Light-emitting diode microscopy: • Less expensive, accurate • Radiography: • Sputum culture:

24. Tuberculin test • Purified Protein Derivative • Intradermal, flexor surface –forearm: 1 TU • Result after 3 days

25. Continued….. • Erythema, induration • Horizontal transverse diameter: plastic ruler

26. Readings • > 10 mm: positive • <5 mm: negative • 5-9 mm: doubtful • Child < 2 years: positive-indirect evidence of active TB lesion

27. Treatment : Anti-TB drugs Bactericidal: • Rifampicin • Isoniazid • Streptomycin • Pyrazinamide

28. Continued….. Bacteriostatic: • Ethambutol • Thioacetazone Second line drugs: • Fluroquinolones • Ethionamide • Capreomycin • Kanamicin, amikacin • Cycloserine

29. DOTS

30. DIRECTLY OBSERVED TREATMENT, SHORT COURSE (DOTS) CHEMOTHERAPY • Intensive phase- trained worker watches, patient swallows drug in his presence • Continuation phase- medicines for 1 week in a multiblistercombipack, first dose swallowed in presence of health worker

34. Daily regimen • In 2013: National Expert Committee • Will be implemented shortly • Category 1: • IP: 2HRZE, CP: 4HR • Category 2: • IP: 2HRZES+1HRZE, CP: 5HRE

35. MDR TB • Resistant: isoniazid, rifampicin • XDR TB: • almost all second line drugs • Rifampicin and Isoniazid • Fluroquinolone • One of: amikacin, capreomycin, kanamycin • MDR: 2.1% • Resistance in re-treatment: 13-17%

36. Types and causes • Primary or pre-treatment: • Not received drug before-episomes • Secondary or acquired: • Initially sensitive • Incorrect prescription • Irregular supply drugs • Non-compliance • Lack of supervision, follow-up

37. MDR TB • Resistant: isoniazid, rifampicin • XDR TB: • almost all second line drugs • Rifampicin and Isoniazid • Fluroquinolone • One of: amikacin, capreomycin, kanamycin

38. Types and causes • Primary or pre-treatment: • Not received drug before-episomes • Secondary or acquired: • Initially sensitive • Incorrect prescription • Irregular supply drugs • Non-compliance • Lack of supervision, follow-up

39. DOTS-Plus (Cat IV)

40. XDR TB treatment

41. Questions • Advantages of DOTS therapy (3 marks) • Defaulters in TB treatment (3 marks) • Define TB control. Explain it in detail (1+5=6 marks) • Explain early detection of tuberculosis (6 marks) • Define new case, relapse, failure with reference to TB (3 marks) • Explain briefly Mantoux Test (3 marks)

42. Questions 7. Enumerate the cardinal features of TB (2 marks) 8. What is supervised treatment in TB ( 2 marks) 9. Components of DOTS ( 3 marks) 10. Define MDR and XDR TB ( 3 marks) 11. DOTS-Plus strategy (3 marks).

43. Thank you