THE EARLY DIAGNOSIS OF PULMONARY TUBERCULOSIS

Transcription

1 THE EARLY DIAGNOSIS OF PULMONARY TUBERCULOSIS AM Edwards Lecture Rocky Mountain/ACP Internal Medicine Meeting Banff Park Lodge Banff, AB November 25, 2011

2 Declaration of Conflict of Interest (This is a mandatory requirement for all speakers at Faculty of Medicine and Dentistry University of Alberta Undergraduate, Graduate, Postgraduate or Continuing Education events) I, Richard Long declare that in the past 3 years: I, Richard Long declare that in the past 3 years: I have received manufacturer funding from the following companies*: I have done consulting work for the following companies*: I have done speaking engagements for the following companies*: I or my family hold individual shares in the following*: No No None None *pharmaceutical or medical/dental equipment

3 No. of Features Suspecting Pulmonary TB 7. Is there an upper lung zone infiltrate (cavitary or non-cavitary) on CXR; is the leucocyte count normal; is there an anemia of chronic disease? Probability of TB 6. Is there a high risk medical condition? 5. Has there been a failure to respond to broad spectrum antibiotics? 4. Are symptoms subacute or chronic? 3. Is there a relative absence of dyspnea? 2. Are there pulmonary symptoms (cough, sputum, hemoptysis, chest pain) in combination with constitutional symptoms (fever, night sweats, weight loss, fatigue)? 1. Is there an epidemiologic risk (TB contact; high risk population group)?

4 1. Is there an epidemiologic risk (for example is there a history of TB contact; are they from a high risk population group)?

5 Annual Age and Sex-Adjusted Tuberculosis Case Rates Per 100,000 Person-Years For Status Indians, Canadianborn Others and Foreign-born, Canada, Status Indian Canadian-born 'other' Foreign-born Int J tuberc Lung Dis 2012 (In Press)

6 Percent of Immigrants from Europe and Asia/Africa to Canada by Time Period (Source: Citizenship and Immigration Canada. Canadian Statistics: Immigrant Population. 05/12/03.<

7 Territory size shows the proportion of worldwide tuberculosis cases found there.

8 The dynamic relationship between Mycobacterium tuberculosis and the human host; a balance between the ability of the organism to adapt to a variety of environmental conditions and host cell-mediated immunity.

9 Jill Stanton, 2011

10 PEDIATR INFECT DIS J 2005; 24:538-41

11 Adult (Age >14 years) Sputum Smear-positive Pulmonary TB (Source Cases) and Outbreaks of TB in Alberta (January 1, June 30, 2008) * Location No. of Source Cases No. of Source Cases Causing Outbreaks Population Group of Source Cases Causing Outbreaks FN Métis FB CBO No. of Secondary Cases in Each Outbreak On-reserve , 2, 3, 3 Off-reserve , 2, 2, 3, 4 *Abbreviations: FN First Nations; FB foreign-born; CBO Canadian-born 'other' Secondary Cases were of 3 types: type 1 - identified by conventional epidemiology and confirmed by molecular epidemiology; type 2 - identified by conventional epidemiology but unconfirmed by molecular epidemiology (culture-negative); type 3 - identified by molecular epidemiology and linked to the source case spatially and temporally.

12 Large Reported, On-reserve Outbreaks of Tuberculosis on the Canadian Prairies, * Outbreak (Reference) Year Treaty Area Community Population Age Source Case Characteristics Sex Population Group Smear Status Total Total Culturepositive Constituent Cases by Age (Yrs) CXR Cases Cases <15 15 A( 1) F FN + ve C B(2) F FN + ve C C(2) M FN + ve C * Abbreviations: F female, M male; FN First Nations; C cavitary Both women were post-partum Cases# 1 and 2 had far-advanced cavitary pulmonary TB; Case #3 moderately-advanced cavitary pulmonary TB M. tuberculosis isolates from outbreaks #1 and #2 were confirmed to share the same DNA fingerprint (1) CAN J INFECT DIS 1991; 2: (2) CAN J PUBLIC HEALTH 2004; 95:

13 The convergence of factors necessary for the occurrence of an outbreak in a reserve community

14 Chest X-ray on the Outbreak Case

15 Cluster Cases by Population Group and Community; Outbreak Timelines

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17 2. Are there pulmonary symptoms (cough, sputum, hemoptysis, chest pain) in combination with constitutional symptoms (fever, night sweats, weight loss, fatigue)?

18 3. Is there a relative absence of dyspnea?

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21 FEV1 101 (% pred) FVC 96 (% pred) FEV1/FVC 80.6 (% pred) DCO 80 (% pred) PaO2 88 (mm Hg) PaCO2 34 (mm Hg) ph 7.45

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24 4. Are the symptoms subacute or chronic?

25 5. Has there been a failure to respond to broad spectrum antibiotics?

26 6. Is there a high risk medical condition?

27 Canadian TB Standards, 6 th Edition. Chapter 4, Pg65

28 7. -Is the total leucocyte count normal. -Is there an anemia of chronic disease? -Is there an upper lung zone infiltrate (cavitary or noncavitary) on CXR.

29 INT J TUBERC LUNG DIS 2002; 6(4):

30 Apr Apr May Patient B is a middle aged foreign-born male who presented to a tertiary care ED on three occasions, April 10, 17, and May 5, CXRs were performed on each occasion but TB was not considered until the last visit, May 5 (delay 24 days).

31 DISTRIBUTION: Commentary: (i) airspace interstitial process involving the apical-posterior segment of the upper lobe and/or the superior segment of the lower lobe, (ii) may be bilateral; if not the contra-lateral lung may be used for comparison. 2 CAVITATION: Commentary: (i) at site of airspace/interstitial disease (present in 50% of cases), (ii) usually round (the broncho-cavitary junction behaves as a check-valve) and thick walled, (iii) may be multiple, (iv) air-fluid levels are uncommon. 3 VOLUME LOSS: Commentary: (i) local, at the site of disease, with relative preservation of total lung volume, (ii) shift of upper mediastinum, retraction of ipsilateral hilum, (iii) bronchiectasis, iv) fibrotic lesions alone are usually sharply defined and irregular, (v) possible pleural thickening. 4 ENDOBRONCHIAL SPREAD: Commentary: (i) acinar shadows - multiple poorly defined nodules 4-10 mm in diameter, (ii) at site of disease, in the dependent lung or in the contra-lateral lung, (iii) lesions are not discrete as in interstitial lung disease.

32 Public Health Consequences (Secondary Cases) of Smear Positive Pulmonary TB According to CXR Category and Close Contact group Type 1 Type 2 Type Typical Atypical *Type 1 secondary cases are identified by conventional epidemiology and confirmed by molecular epidemiology; Type 2 secondary cases are identified by conventional epidemiology but are unconfirmed by molecular epidemiology (culture-negative); Type 3 secondary cases are identified by molecular epidemiology and linked to the source case spatially and temporally

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36 If you suspect pulmonary TB Submit Sputum for AFB smear and Culture ASAP!