Unit 6: Diagnosing TB

1. Unit 6: Diagnosing TB Botswana National Tuberculosis Programme Manual Training for Medical Officers

2. Objectives At the end of this unit, participants will be able to: Diagnose pulmonary tuberculosis disease using sputum smears Diagnose smear negative pulmonary TB disease Diagnose extra-pulmonary TB disease

3. Diagnosis of Tuberculosis Priority is in diagnosing and curing infectious cases ALL persons with TB symptoms should also be tested for HIV Routine HIV testing in Botswana Rapid HIV testing available in all public health facilities

4. Common Sites of TB Disease • Lungs • Pleura • Central nervous system • Lymphatic system • Genitourinary systems • Bones and joints • Disseminated (miliary TB) • Pericardial disease Source: CDC, 2001.

5. The Effect of HIV Infection on Symptoms and Signs of TB TB is more common in HIV infected persons, systemic symptoms are very common HIV-related immunosuppression doesn’t always allow the body to contain TB disease to a single organ system Must be looking for signs and symptoms of both pulmonary and extrapulmonary TB

6. Case Finding (1) Highest priority to find and cure infectious cases: people with smear-positive PTB Two ways of identifying TB cases: Passive case finding: illness diagnosed when patient presents for medical care at health facility Active case finding: health workers actively search for patients with TB in the community

7. Who is a TB Suspect? “Any person who presents with symptoms or signs suggestive of TB, in particular cough of long duration (more than 2 weeks).” Source: WHO, 2003

8. Case Finding (2) Most common tools for case finding include: • History taking • Physical examination • Sputum examination • X-ray examination • Tuberculin skin testing

9. Active Case Finding Contact investigation most common method in Botswana Other methods include special surveys based on: Geography Targeted testing of defined populations (e.g., schools, prisons)

10. Clinical Presentation Take a thorough history for each patient Determine if signs and symptoms point to pulmonary or extrapulmonary TB Also obtain medical and social history Do a general physical examination with additional care to detect signs of tuberculosis

11. Medical History • Have you had close contact with someone with TB? • Do you have a cough? How long, dry, productive, colour? • Is blood present in your sputum? • Do you have chest pain? When & where? • Do you have shortness of breath? How long? • Do you sweat profusely at night? • Have you lost weight? • When did you start losing weight? • When did you lose your appetite? • How long have you been feeling weak and tired? • Do you smoke? • Have you previously been tested for TB? • Do you know your HIV status? Source: Chiang C-V et al., 2007.

12. Common Symptoms of Adult Pulmonary TB (1) • Cough (prolonged) for two to three weeks • Any person with this symptom is classified as TB suspect • Sputum • Fever/ night sweats • Weight loss, wasting in advanced cases • Shortness of breath • Malaise

13. Common Symptoms of Adult Pulmonary TB (2) • Haemoptysis • Chest pain • Tachypnoea (abnormally fast breathing) • Anaemia • Abnormal breath sounds • Loss of appetite

14. Pulmonary TB Diagnosis How do you currently diagnose pulmonary tuberculosis disease?

15. PTB types, BNTP 2005 Source: BNTP, 2005

16. Sputum Smears Smear microscopy is widely available and accessible for diagnosis in Botswana When pulmonary TB is suspected, three sputum specimens must be collected for examination Outpatient: “spot-early morning-spot” Inpatient: three early morning specimens over three consecutive days

17. Sputum Collection Techniques (1) Sputum collection should be done outside or in an empty room with very good ventilation If above not possible, try for best possible ventilation Use sterile glass or plastic containers, 5-6 cm deep, with screw cap

18. Sputum Collection Techniques (2) • The health worker should explain and demonstrate procedure • The health worker should supervise, but should NOT stand in front of the patient • Collect away from other people • Only sputum (2-5 ml) should be accepted as a good specimen • Saliva (white, watery, frothy) should not be accepted because it will yield useless and misleading results

19. Specimen Quality Poor quality sputum Source: CDC, 2007 Better quality

20. Patient Instructions: Sputum Collection (1) Explain clearly to patient: • Why sputum is needed • Three samples required • Spot–morning-spot • What a “good” sample is and how to obtain it • Opening and tight closing of containers • Not to soil the exterior of the container • Not to expose the sample to sunlight • Transport of sputum containers • The need to return to the clinic

21. Patient Instructions: Sputum Collection (2) Rinse mouth and throat with water two to three times, and drink some water to wet throat (for easy spitting of viscid sputum) Inhale deeply 2-3 times, breathe out hard each time Keep the body inclined to front Cough deeply from the chest Open the container and keep it near mouth and spit sputum in Close lid securely Wash hands after handling sputum container Bring container to HCW

22. Sputum Smear Examination Specimens should be sent to lab as soon as possible Complete Mycobacteriology Request and Report Form Always aim for three specimens from each suspect Spot-early morning-spot specimen collection will detect 90% of smear-positive cases

23. Acid-Fast Smear Showing TB Bacilli © University of Alabama at Birmingham, Department of Pathology

24. Mycobacteriology Request and Report Form • Must be completed by HCW for each specimen submitted to lab, and must accompany it to the lab • Smear microscopy • TB culture • Drug sensitivity testing • Completed suspect register • Lab will: • Process specimen • Complete “REPORT” section on form’s lower half • Return to requesting HCW or treatment unit

25. Sputum Results • Once Mycobacteriology Request and Report form is received back in the clinic, the receiving HCW should record the results in: • TB Treatment card • The Suspect and Sputum Dispatch Register • Facility TB Register as appropriate

26. Recording Sputum Smear Microscopy Results

27. Why the Emphasis on Sputum Smears? © University of Alabama at Birmingham, Department of Pathology © ITECH, 2006 Direct Microscopy is the most reliable and cost effective way to identify persons who are most likely to transmit TB to others

28. What does a Positive Sputum Smear Mean? • Positive smear predicts higher contagiousness to others • Smears may be positive and not mean TB • Due to laboratory error or MOTT • Sensitivity and specificity of a positive smear depends on prevalence of MOTT and HIV in a population

29. NTRL Culture Performance: 2004-2006 Data for analysis granted by NTRL and BOTUSA

30. Botswana Laboratory Network: Referral System Mobile Stops Health Posts 5 Clinic Laboratories (Council) 16 Primary Hospital Laboratories 3 Mine Hospital Laboratories 6 District Hospital Laboratories 2 Referral Hospital Laboratories BNTRL 3 Reference Laboratories

31. Primary and District LabServices in TB control (Level 1) • Receipt of specimens: from clinics • Preparation and staining of smears • ZN microscopy /recording • Reporting of results • Maintenance of lab register • Management of reagents and supplies • Internal Quality Control (QC) • Collect specimen for culture and DST, send to NTRL • Participation in EQA

32. Nyangagbwe Referral lab (Level 2) Activities: receive specimen for AFB and culture Services to clinics: FM/ZN smear microscopy (smear microscopy and send results) Support activities: (supply of reagents/ materials, training; EQA for smear microscopy including supervision) Inoculate specimen and refer to NTRL for incubation and DST

33. Role of NTRL in TB Control • Identify mycobacterium other than MTB • DST of M. Tuberculosis • TB laboratory equipment services and maintenance • Develop TB Lab manuals and guidelines • Primary link with NTP • Supervision of intermediate QA of culture and microscopy • Operational and applied research • Provide EQA and monitor peripheral labs

34. Diagnosing Smear-Negative PTB Some seriously ill patients may have sputum AFB smear results and may die of TB if untreated High index of suspicion if there are: Miliary changes on chest x-ray (CXR) Compatible CXR and no response to Rx for bacterial infection Pleural effusion Inthrathoracic adenopathy Pericardial effusion Source: Lockman S et al., 2003.

35. Algorithms for Diagnosis of PTB Algorithm for diagnosis of PTB in ambulatory patients Algorithm for diagnosis of PTB in seriously ill patients

36. Mycobacterial Culture (1) “Gold Standard” of TB diagnosis More expensive and more time consuming than microscopy Requires specialised training and media to perform Not recommended for routine case detection in Botswana Courtesy of: Kubica G, 2007.

37. Mycobacterial Culture (2) Reasons to request mycobacterial culture: • Patient previously on anti-TB treatment • Still smear-positive after intensive phase of treatment or after finishing treatment • Symptomatic and at high-risk of MDR-TB • To test fluids potentially infected with M. tuberculosis • Investigation of patients who develop active PTB during or after IPT • TB in health workers

38. DST performed on all cultures Tests for isoniazid, rifampicin, ethambutol, and streptomycin If found to be multi-drug resistant, then send for additional testing for susceptibility to second-line medicines TB Drug Susceptibility Testing (DST)

39. Role of Radiography Chest X-Ray (CXR) can support a diagnosis of PTB Not used routinely for follow-up PTB can exist with normal CXR Must be interpreted with other information History and exam Sputum smear results Also useful in diagnosing other types of TB, especially in bones, joints, and spine

40. Courtesy of: San Francisco City and County Dept. of Public Health, TB Division

41. Pulmonary TB Diagnosis Are there any special challenges in diagnosing pulmonary TB among persons with HIV?

42. Sputum Smear and HIV Status HIV positive patients with pulmonary TB often have negative sputum smears Important to recognise the clinical and chest radiographic characteristics of HIV-TB, so patients who are smear-negative can be recognised and treated appropriately

43. Early HIV disease Cavity or upper lobe pulmonary disease Positive sputum smear microscopy Pleural disease Advanced HIV disease Sputum smear negative pulmonary disease Disseminated TB Pleural or pericardial effusion with or without intrathoracic adenopathy Lower and middle lobe infiltrates Effect of HIV Stage on Manifestations of TB

44. Severe immunodeficiency can have a dramatic effect on the CXR manifestations of TB Not classic TB picture on CXR Reticulonodular infiltrates (disseminated TB) seen, but often without the classic miliary pattern Intrathoracic adenopathy (mediastinal or hilar adenopathy) relatively common among patients with advanced HIV-TB It is critical to understand this relationship so that patients with HIV-TB will be recognized and treated Effect of Immunosuppression on CXR in HIV-Related TB Source: Post FA et al. Tuber Lung Dis. 1995.

45. Chest X-Ray Patterns and CD4 Counts Radiographic features associated with the degree of HIV-related immunosuppression in patients with HIV-related pulmonary TB: Intrathoracic adenopathy associated with low CD4 count Cavitation and infiltrates more common in patients with CD4 > 200 and those with less- advanced HIV Source: Perlman DC, et al.Clin Infect Dis, 1997.

46. Example of Immunosuppressed TB Suspect 23 year old male, HIV infected, recent CD4 count was 35 He has cough, loss of appetite and weight loss for 3 weeks His sputum smear for AFB was negative, therefore a CXR was done

47. What Do You See? (1) © I-TECH, 2003

48. What Do You See? (2) Courtesy of: Huang L, HIV InSite Knowledge Base, 1998.

49. What Do You See? (3) Courtesy of: Gooze L,et al., HIV InSite Knowledge Base, 2003.

50. What Do You See? (4) Courtesy of: Gooze L,et al. HIV InSite Knowledge Base, 2003.