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Clinical Presentation and Diagnosis of TuberculosisYour name Institution/organizationMeetingDate
International Standards 1-5
ISTC TB Training Modules 2009
Clinical Presentation and Diagnosis of TB
Objectives: At the end of this presentation,participants will be able to: Describe the signs/symptoms and risk factors that
should raise suspicion for the diagnosis of TB Understand the importance of sputum smear
microscopy, as well as the need to obtain specimens for microbiologic examination from extrapulmonary sites
Recognize that CXR alone is not sufficient for the diagnosis of TB
List criteria used for the diagnosis of smear-negative TB
ISTC TB Training Modules 2009
Clinical Presentation and Diagnosis of TB
International Standards 1, 2, 3, 4, and 5
Overview: General considerations Signs and symptoms Role of AFB smear Radiographic
presentation AFB smear-negative
diagnosis
ISTC TB Training Modules 2009
Standards for Diagnosis
ISTC TB Training Modules 2009
Rapid, accurate diagnosis is essential for individual and public health
Despite technical advances, clinical acumen with a high index of suspicion remains vital to the diagnosis of TB Think TB
Fundamental Principles
ISTC TB Training Modules 2009
“Classic” TB Clinical Presentation
Insidious onset and chronic course Chest symptoms
• Cough (usually productive)• Hemoptysis• Chest pain (usually pleuritic)
Nonspecific constitutional symptoms (more common in children and HIV)
Extrapulmonary symptoms (if involved)
ISTC TB Training Modules 2009
Nonspecific Systemic Symptoms
Fever in 65-80% of cases
Chills/night sweats
Fatigue/malaise
Anorexia/weight loss
However, 10-20% of TB cases have no symptoms at the time of diagnosis
ISTC TB Training Modules 2009
Diagnosis of TB in HIV
Cannot rely on “typical” indicators of TB
Fever and weight loss are important symptoms
Cough is less common
Chest radiographic pattern more variable
More extrapulmonary and disseminated TB
Differential diagnosis is broader
ISTC TB Training Modules 2009
Standard 1: Prolonged Cough
All persons with otherwise unexplained productive cough lasting two-three weeks or more should be evaluated for tuberculosis
ISTC TB Training Modules 2009
Prolonged Cough
Think TB: Prolonged Cough (2-3 weeks) Cough may not be specific for TB,
however, long duration raises likelihood of TB diagnosis
Criterion for suspecting TB in most national and international guidelines
Percentage of AFB smear-positive sputum increases with increasing duration of cough
Will not identify all TB cases; use best clinical judgment
ISTC TB Training Modules 2009
Clinical Presentation: Risk Factors
Risk for Recent Infection Contact with active TB case Occupational risk – e.g. healthcare worker Crowded conditions – e.g. jails, institutional
residences Recent stay in a healthcare facility
ISTC TB Training Modules 2009
Clinical Presentation: Risk Factors
Risk of Progression to Active TB HIV infection Abnormal CXR suggestive of prior TB (with
inadequate treatment) Children (less than 5 years of age) Underlying medical conditions
• Immunosuppressive therapy
• Malnutrition
• Diabetes, renal failure, and other conditions
• Tobacco use, injection drug use (?)
ISTC TB Training Modules 2009
Clinical Presentation: Physical Examination
May be normal in mild–moderate disease Chest: rales, rhonchi; absent breath sounds
and dullness to percussion if pleural fluid is present
Extrapulmonary (site specific): adenopathy, skin lesions, bone tenderness, neck stiffness, etc.
The physical examination is nonspecific, but it is helpful to identify extrapulmonary sites of involvement
ISTC TB Training Modules 2009
Standard 2: Sputum Microscopy
All patients (adults, adolescents, and children who are capable of producing sputum) suspected of having pulmonary TB should have at least two sputum specimens obtained for microscopic examination in a quality-assured laboratory. When possible, at least one early morning specimen should be obtained.
ISTC TB Training Modules 2009
Sputum Microscopy
To prove a diagnosis of TB, every effort must be made to identify the causative agent
The AFB smear in high-prevalence areas is:• Highly specific for TB
• Most rapid method for determining TB diagnosis
• Identifies those at greatest risk of dying from TB
• Identifies those most likely to transmit disease
ISTC TB Training Modules 2009
Mase SR, Int J tuberc Lung Dis 2007;11(5): 485-95
Average yield of single early morning specimen: 86.4%Average yield of single spot specimen: 73.9%
Specimen Number
Incremental Yield of smear specimens
(of all smear positive)
Incremental Sensitivity of smear specimens
(compared with culture)
1 85.8% 53.8%
2 11.9% 11.1%
3 2.4% 3.1%
Total 100% 68.0%
Performance of Sputum Microscopy
ISTC TB Training Modules 2009
54-year-old man with three months of focal low-back pain
Can this be TB? Extrapulmonary
“Pott’s disease” Signs and symptoms of extrapulmonary TB are
site specific Sampling of extrapulmonary sites for smear,
culture, and histopathology may confirm diagnosis
ISTC TB Training Modules 2009
Standard 3: Extrapulmonary Specimens
For all patients (adults, adolescents, and children) suspected of having extrapulmonary TB, appropriate specimens from the suspected sites of involvement should be obtained for microscopy, culture, and histopathological examination.
ISTC TB Training Modules 2009
Pulmonary, 71%
Extrapulmonary, 20%
Both, 9%
Pleural, 18%
Lymphatic, 42%
Bone/joint, 11% Genitourinary, 5%
Meningeal, 5%
Other, 13%
TB Cases by Form of Disease,United States, CDC, 2008 Peritoneal, 6%
Clinical Presentation: Extrapulmonary
Incidence/site may vary TB can involve any organ More common in HIV/TB
ISTC TB Training Modules 2009
Extrapulmonary Tuberculosis
ISTC TB Training Modules 2009
Radiographic Presentation of TB
ISTC TB Training Modules 2009
Standard 4: Evaluation of Abnormal CXR
All persons with chest radiographic findings suggestive of tuberculosis should have sputum specimens submitted for microbiological examination.
ISTC Training Modules 2008
ISTC TB Training Modules 2009
Distribution
Apical / posterior segments of upper lobes
Superior segments of lower lobes
Isolated anterior segment involvement is unusual
Can this be TB?
Typical Pattern: Reactivation, Post-primary TB
ISTC TB Training Modules 2009
Reactivation/Post-primary TB
Patterns of disease Air-space consolidation Cavitation, cavitary
nodule Miliary Fibro-nodular densities Nodule (Tuberculoma) Pleural effusions
ISTC TB Training Modules 2009
Can this be TB?
Distribution: Any lobe involved (slight lower lobe predominance)
Air-space consolidation Cavitation is uncommon
(< 10%) Adenopathy is common
(esp. in children and HIV) Miliary pattern
Atypical pattern: Primary TB
ISTC TB Training Modules 2009
Can this be TB? Miliary TB
ISTC TB Training Modules 2009
Can this be TB?
Findings suggestive of prior TB
Ca+ granuloma – Ghon lesion Ca+ granuloma and hilar node
calcification – Ranke complex Apical pleural
thickening Fibrosis and
volume loss
ISTC TB Training Modules 2009
CXR Issues
Reliance on chest radiograph alone results in both over-diagnosis and missed diagnosis of TB and other diseases
Radiography needs to be held to high standards of technical quality and interpretation
Results of poor imaging quality may be harmful to patient care
ISTC TB Training Modules 2009
Evaluation of Abnormal CXR
Study from India: 2229 outpatients evaluated by CXR/culture
Of 227 cases deemed TB by CXR alone• 36% had negative sputum cultures for TB
Of 177 culture-positive cases of TB• 18% would have been missed based on CXR
alone
CXR alone is not enough
Nagpaul DR, Proceedings of the 9th Eastern Region Tuberculosis Conference and 29th National Conference on Tuberculosis and Chest Diseases. 1974 Delhi,
as cited in Toman’s tuberculosis. Case detection, treatment and monitoring, 2nd Edition: World Health Organization, 2004
ISTC TB Training Modules 2009
The diagnosis of sputum smear-negative pulmonarytuberculosis should be based on the following criteria: At least two negative sputum smears (including at
least one early morning specimen) Chest radiography findings consistent with
tuberculosis Lack of response to a trial of broad-spectrum
antimicrobial agents (Note: Because the fluoroquinolones are active against M. tuberculosis complex, and thus may cause transient improvement in persons with tuberculosis, they should be avoided.)
Standard 5: Smear-negative Diagnosis
(1 of 2)
ISTC TB Training Modules 2009
(Continued) For such patients, sputum cultures should
be obtained. In persons who are seriously ill or have
known or suspected HIV infection, the diagnostic evaluation should be expedited and if clinical evidence strongly suggests tuberculosis, a course of antituberculosis treatment should be initiated.
Standard 5: Smear-negative Diagnosis
ISTC Training Modules 2008
(2 of 2)
ISTC TB Training Modules 2009
Clinical assessment, HIV test1, sputum smear microscopy
At least 2 sputum specimens AFB negative
HIV + and/or severe illness2 HIV-, mild/moderate illness2
1. Recommended in countries or areas with adult HIV prevalence >1% or prevalence among TB cases >5%
2. Severe illness = respiratory rate >30 breaths/min, temperature >39°C, pulse >120 beats/min, unable to walk unaided, symptoms/signs progressing rapidly
TB Diagnostic AlgorithmSPUTUM SMEAR-NEGATIVE TB
ISTC TB Training Modules 2009
HIV + and/or severe illness
SPUTUM SMEAR-NEGATIVE TB
Clinical/radiographic findings NOT suggestive of TB
Negative culture
Consider other diagnoses
Not TB
• Clinical/radiographic findings suggestive of TB
• Positive or negative culture
Treat (empiric TB treatment before confirmed diagnosis if severe illness)
• HIV staging • Evalutate for ARVs • CPT prophylaxis
Repeat clinical assessment Chest radiograph Sputum culture (or other test)
Parenteral broad-spectrum antimicrobials (excluding fluoroquinolones)
TB Diagnostic Algorithm
TB
ISTC TB Training Modules 2009
HIV–, mild/moderate illness
SPUTUM SMEAR-NEGATIVE TB
Broad-spectrum antimicrobials(excluding anti-TB drugs and fluoroquinolones)
Consider other diagnosis
Repeat clinical assessment Chest radiograph Sputum culture (or other test)
Treat
TB Diagnostic Algorithm
NO IMPROVEMENT
Not TB Not TBTB
Clinical/radiographic findings NOT suggestive of TB
Negative culture
Clinical/radiographic findings suggestive of TB
Positive culture
IMPROVEMENT
ISTC TB Training Modules 2009
Clinical Presentation and Diagnosis of TB
Additional points:
Symptoms/severity: none to overwhelming Tempo of illness: ranges from indolent to fast TB can involve any organ or tissue Signs/symptoms may be both local and
systemic Consider HIV testing in the diagnostic
evaluation
TB is capable of presenting in many ways
ISTC TB Training Modules 2009
Clinical Presentation and Diagnosis of TB
Summary: Think TB A prolonged duration of cough should raise TB
suspicion and trigger a diagnostic evaluation TB risk factors and exposure increase level of
suspicion AFB smear in high-prevalence areas is highly
specific and most rapid tool for diagnosing TB Radiographic patterns may help in TB diagnosis
if suspicion high and AFB smear is negative, but a radiograph alone is not enough to make diagnosis
ISTC TB Training Modules 2009
* Abbreviated versions
Summary: ISTC Standards Covered*
Standard 1: Unexplained productive cough lasting 2-3 weeks or more should be evaluated for tuberculosis.
Standard 2: All TB suspects should have at least 2 sputum specimens obtained for microscopic examination (at least one early morning specimen if possible) in a quality-assured laboratory.
Standard 3: Specimens from suspected extrapulmonary TB sites should be obtained for microscopy, culture and histopathological exam.
ISTC TB Training Modules 2009
Summary: ISTC Standards Covered*
* Abbreviated versions
Standard 4: All persons with chest radiographic findings suggestive of TB should have sputum specimens submitted for microbiological examination.
Standard 5: The diagnosis of smear-negative pulmonary TB should be based on the following: at least two negative sputum smears (including at least one early morning specimen); CXR finding consistent with TB; lack of response to broad-spectrum antibiotics (avoid fluoroquinolones), and culture data. Empiric treatment if severe illness.
ISTC TB Training Modules 2009
Alternate Slides
ISTC TB Training Modules 2009
Purpose of ISTC
ISTC TB Training Modules 2009
ISTC: Key Points
21 Standards (revised/renumbered in 2009) Differ from existing guidelines: standards
present what should be done, whereas, guidelines describe how the action is to be accomplished
Evidence-based, living document Developed in tandem with Patients’ Charter
for Tuberculosis Care Handbook for using the International
Standards for Tuberculosis Care
ISTC TB Training Modules 2009
Audience: all health care practitioners, public and private
Scope: diagnosis, treatment, and public health responsibilities; intended to complement local and national guidelines
Rationale: sound tuberculosis control requires the effective engagement of all providers in providing high quality care and in collaborating with TB control programs
ISTC: Key Points
ISTC TB Training Modules 2009
Questions
ISTC TB Training Modules 2009
Clinical Presentation and Diagnosis of TB
1. A 32 year-old man complains of cough and malaise for the past three weeks. His wife is currently being treated for active tuberculosis. Of the following choices, your first step would be:
A. Begin an empiric trial of treatment with a fluoroquinolone antibiotic for a possible community-acquired pneumonia
B. Obtain a chest film to confirm your suspicion for TB which will make sputum testing unnecessary
C. Obtain two sputum specimens for AFB microscopy (including at least one early morning specimen)
D. Both answers A and C
ISTC TB Training Modules 2009
Clinical Presentation and Diagnosis of TB
2. In high prevalence areas, the AFB sputum microscopy smear:
A. Is highly specific for TB
B. Identifies those at greatest risk of dying from TB
C. Identifies those most likely to transmit disease
D. All of the above
ISTC TB Training Modules 2009
Clinical Presentation and Diagnosis of TB
3. A 54 year-old woman complains of cough, fever, and unexpected weight loss over the past month. She admits smoking 10 cigarettes per day for over 20 years. Two sputum smears were negative for AFB. You would consider each of the following except:
A. An empiric trial of antibiotics (non-fluoroquinolone)
B. Obtaining a chest film for further evaluation
C. A trial of bronchodilator medication alone and follow-up in 3 months
D. Sending sputum specimens for AFB culture
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