Clinical Presentation and Diagnosis of Tuberculosis Your name Institution/organization Meeting Date International Standards 1-5.
Presentation on theme: "ISTC TB Training Modules 2009"— Presentation transcript:
1 ISTC TB Training Modules 2009 Clinical Presentation and Diagnosis of TuberculosisInstructor’s Guide and Teaching NotesModule: Clinical Presentation and Diagnosis of Tuberculosis (animated)ISTC Standards covered: 1 – 5Module Time: Approximately 60 minutesAlternate slides: Introductory ISTC slides.Interactive options: Ideas for interactive discussions are offered on many of the slides in this module. Participant discussion can enhance active learning, but will add more time to the lecture and must be planned for.Slide-show Animation: A second version of this talk is available without slide animations.Additional Material: Slides containing related material may be found in the following modules: Microbiological diagnosis of Tuberculosis, TB and HIV Infection: Introduction and Diagnosis.Test Questions: May be attached or inserted within presentation for discussion purposes, or alternatively, combined with questions from other modules to produce evaluation tool.The full text of the ISTC and all supporting references are available atOther useful Resources/References:Management of tuberculosis training for health facility staff. World Health Organization,Radiographic Manifestations of Tuberculosis: A Primer for Clinicians, Second Edition. Francis J. Curry National Tuberculosis Center.Toman’s tuberculosis. Case detection, treatment and monitoring, 2nd Edition. Freiden TR ed., World Health Organization,A Tuberculosis Guide for Specialist Physicians. Jose A. Caminero Luna, IUATLD, Sept[Image credit: World Lung Foundation/Jad Davenport]Your nameInstitution/organizationMeetingDateInternational Standards 1-5
2 Clinical Presentation and Diagnosis of TB ISTC TB Training Modules 2009Objectives: 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 TBUnderstand the importance of sputum smear microscopy, as well as the need to obtain specimens for microbiologic examination from extrapulmonary sitesRecognize that CXR alone is not sufficient for the diagnosis of TBList criteria used for the diagnosis of smear-negative TBIt is intended that after completion of this module the student will be able to describe the approach to diagnosis of TB and the proper role of diagnostic testing, particularly sputum microscopy, in that process.[Review content of slide]
3 Clinical Presentation and Diagnosis of TB ISTC TB Training Modules 2009Overview:General considerationsSigns and symptomsRole of AFB smearRadiographic presentationAFB smear-negativediagnosisOverview of Clinical Presentation and Diagnosis of TB[Review overview from slide]Lecture/module includes International Standards 1 - 5[Image of sputum smear photomicrograph reveals Mycobacterium tuberculosis bacteria using acid-fast Ziehl-Neelsen stain][Image credits: World Lung Foundation/Jad Davenport (top); CDC Public Health Image Library/Dr. George P. Kubica (bottom)]International Standards 1, 2, 3, 4, and 5
4 Standards for Diagnosis ISTC TB Training Modules 2009In introducing the Standards for Diagnosis of TB, it is important to recognize: [Review content of slide][Image credit: World Lung Foundation/Virginia Arnold]
5 Fundamental Principles ISTC TB Training Modules 2009Rapid, accurate diagnosis is essential for individual and public healthDespite technical advances, clinical acumen with a high index of suspicion remains vital to the diagnosis of TBTherefore, two fundamental points that should be stressed are: [Review content of slide][Click: Slide-show Animation]To diagnose TB, we must Think TB.[Image credit: World Lung Foundation/Pierre Virot] Think TB
6 “Classic” TB Clinical Presentation ISTC TB Training Modules 2009Insidious onset and chronic courseChest symptomsCough (usually productive)HemoptysisChest pain (usually pleuritic)Nonspecific constitutional symptoms (more common in children and HIV)Extrapulmonary symptoms (if involved)Begin with: Classic TB clinical presentation.The most common symptom of pulmonary TB is persistent productive cough, often accompanied by nonspecific constitutional symptoms, such as fever, night sweats, and weight loss.Extra-pulmonary TB, such as lymphadenopathy, may be noted, especially in patients with HIV infection.
7 Nonspecific Systemic Symptoms ISTC TB Training Modules 2009Fever in 65-80% of casesChills/night sweatsFatigue/malaiseAnorexia/weight lossHowever, 10-20% of TB cases have no symptoms at the time of diagnosisNonspecific systemic, constitutional symptoms may include:[Review content of slide][Click: Slide-show Animation]. It is important to also recognize that there are many cases of TB, up to 10-20%, that may present without any symptoms at all.
8 ISTC TB Training Modules 2009 Diagnosis of TB in HIVISTC TB Training Modules 2009Cannot rely on “typical” indicators of TBFever and weight loss are important symptomsCough is less commonChest radiographic pattern more variableMore extrapulmonary and disseminated TBDifferential diagnosis is broaderThe diagnosis of TB with HIV co-infection can be more difficult.Symptoms may be more nonspecific, but fever and weight loss may be more prominent at presentation.Cough and hemoptysis are less common because there may be less cavitation, inflammation and endobronchial irritation in HIV patients.CXR findings can be more variable, with both “typical, post-primary or reactivation TB” and “atypical, primary TB” CXR patterns commonly seen. In people infected with HIV, obtaining a timely CXR plays an important role in shortening delays in diagnosis and should be performed early in the investigation of a TB suspect.The diagnosis of TB may be further complicated by the broader range of possible alternative diagnoses. The physical signs of respiratory infection in patients with pulmonary TB (PTB) do not readily distinguish PTB from other chest diseases and chest examination may even be normal. Because of the broader differential diagnosis, access to and utilization of culture and more invasive diagnostic become more important issues.An accurate TB diagnosis may be further complicated due to the higher rate of extrapulmonary and disseminated disease in HIV-infected individuals.
9 Standard 1: Prolonged Cough ISTC TB Training Modules 2009All persons with otherwise unexplained productive cough lasting two-three weeks or more should be evaluated for tuberculosisSo what guidance do the International Standards for TB Care offer for prioritizing who to evaluate for the diagnosis of TB?Standard 1: [Read Standard][Image credit: WHO]
10 ISTC TB Training Modules 2009 Prolonged CoughISTC TB Training Modules 2009Think TB: Prolonged Cough (2-3 weeks)Cough may not be specific for TB, however, long duration raises likelihood of TB diagnosisCriterion for suspecting TB in most national and international guidelinesPercentage of AFB smear-positive sputum increases with increasing duration of cough Will not identify all TB cases; use best clinical judgmentAlthough most patients with pulmonary TB have cough, the symptom is not specific to TB; it can occur in a wide range of respiratory conditions, including acute respiratory tract infections, asthma, and chronic obstructive pulmonary disease.While the presence of cough for 2-3 weeks is nonspecific, traditionally, having cough of this duration has served as the criterion for defining suspected TB and is used in most national and international guidelines, particularly in areas of moderate- to high-prevalence of TB.Data from India, Algeria, and Chile generally show that the percentage of patients with positive sputum smears increases with increasing duration of cough, and a more recent assessment from India demonstrated that by using a threshold of >2 weeks to prompt collection of sputum specimens, the number of TB cases identified increased by 46%. Simply inquiring about cough can increase yield of cases identified.Certainly, duration of cough is not the only criterion that should raise suspicion for tuberculosis, other features of the presentation may raise your concern for TB in patients with a shorter duration or even absence of cough, therefore [Click: Slide-show Animation] clinical intuition plays an important role in the evaluation for TB. This is particularly true with HIV co-infection where TB presentation may be more atypical and lack of cough more common.[Reference: Santha T., et al. Comparison of cough 2 and 3 weeks to improve detection of smear-positive tuberculosis cases among out-patients in India. Int J Lung Dis 2005;9(1):61-8]
11 Clinical Presentation: Risk Factors ISTC TB Training Modules 2009Risk for Recent InfectionContact with active TB caseOccupational risk – e.g. healthcare workerCrowded conditions – e.g. jails, institutional residencesRecent stay in a healthcare facilityIn evaluating persons who have symptoms that my be caused by TB it is important to identify risk factors for either:Recent infection with M.tb due to transmission risks and/or factors that may increase the likelihood of progression to active TB once an individual is infected.The presence of any of these factors should raise the clinician’s suspicion for TB.Significant risk factors for possible recent infection include:[Review content of slide].
12 Clinical Presentation: Risk Factors ISTC TB Training Modules 2009Risk of Progression to Active TBHIV infectionAbnormal CXR suggestive of prior TB (with inadequate treatment)Children (less than 5 years of age)Underlying medical conditionsImmunosuppressive therapyMalnutritionDiabetes, renal failure, and other conditionsTobacco use, injection drug use (?)Significant risk factors that may increase the likelihood of progression to active TB once an individual is infected include:[Review content of slide][Interactive option – ask participants what risk factors are most prevalent in their local areas and practices? Are there any other special groups or settings not listed here that are important to their region?]
13 Clinical Presentation: Physical Examination ISTC TB Training Modules 2009May be normal in mild–moderate diseaseChest: rales, rhonchi; absent breath sounds and dullness to percussion if pleural fluid is presentExtrapulmonary (site specific): adenopathy, skin lesions, bone tenderness, neck stiffness, etc. The physical examination is nonspecific, but it is helpful to identify extrapulmonary sites of involvementThe physical examination is non-specific in TB but useful to identify sites of TB: [Review content of slide][Click: Slide-show Animation]
14 Standard 2: Sputum Microscopy ISTC TB Training Modules 2009ISTC Training Modules 2008All 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.In persons who are suspected of having TB based on symptoms and/or physical findings, every effort must be made to identify the causative agent.The first important step is highlighted by the International Standard 2: [Read Standard][Note: Guidelines have recently changed from three sputum smears to at least two sputum smears. The change is reflected above and differs from the wording in the original published ISTC][Image shows sputum smear with carbolfuchsin-based stain demonstrating typical acid-fast bacilli morphology][Image credit: CDC Public Health Image Library /Dr. George P. Kubica]1414
15 ISTC TB Training Modules 2009 Sputum MicroscopyISTC TB Training Modules 2009To prove a diagnosis of TB, every effort must be made to identify the causative agentThe AFB smear in high-prevalence areas is:Highly specific for TBMost rapid method for determining TB diagnosisIdentifies those at greatest risk of dying from TBIdentifies those most likely to transmit diseaseWhile a definitive microbiological diagnosis can only be confirmed by culturing M. tuberculosis complex (or, under appropriate circumstances, identifying specific nucleic acid sequences) from clinical specimens, in practice, there are many settings where these tests are not currently feasible (due to resource limitations).Fortunately, microscopic examination of stained sputum, i.e. an AFB smear, is feasible in nearly all settings.In almost all clinical circumstances in high prevalence areas, finding acid-fast bacilli in stained sputum is highly specific and , thus, is the equivalent of a confirmed diagnosis.In addition to being highly specific for M.tb, identification of AFB by smear is particularly important for three reasons:It is the most rapid method for determining if a person has TBIt identifies persons who are at greatest risk of dying from the disease*And it identifies the most likely transmitters of infection*[Note that in persons with HIV infection, mortality rates are greater in patients with clinically-diagnosed TB who have negative sputum smears than among HIV-infected patients who have positive sputum smears.]
16 Performance of Sputum Microscopy ISTC TB Training Modules 2009Specimen NumberIncremental Yield of smear specimens(of all smear positive)Incremental Sensitivity of smear specimens(compared with culture)185.8%53.8%211.9%11.1%32.4%3.1%Total100%68.0%The limitation of sputum smear microscopy is its sensitivity.As illustrated in the table: compared with culture, sputum smear microscopy is 68% sensitive in detecting M. tuberculosis.Of all specimens that are AFB positive nearly 86% are detected by examining one specimen and an additional 12% are found on the 2nd specimen; thus, the incremental yield of the 3rd specimen is very low. A similar increment is found for the sensitivity of the 2nd and 3rd specimens.The yield is better with a single early morning specimen than with a spot specimen obtained at other times during the day.[Reference: Mase SR, et al. Yield of serial sputum specimen examinations in the diagnosis of pulmonary tuberculosis: a systematic review. Int J tuberc Lung Dis 2007;11(5): ]Average yield of single early morning specimen: 86.4%Average yield of single spot specimen: 73.9%Mase SR, Int J tuberc Lung Dis 2007;11(5):
17 Can this be TB? Extrapulmonary ISTC TB Training Modules 200954-year-old man with three months of focal low-back pain“Pott’s disease”Signs and symptoms of extrapulmonary TB are site specificSampling of extrapulmonary sites for smear, culture, and histopathology may confirm diagnosisWhile we often focus on the pulmonary presentation and evaluation for TB, it is important to remember that TB may present in many ways.Can this case be TB? “A 54 year-old man with three months of focal low back pain” presents with this radiographic finding.[Click: Slide-show Animation]Yes, this is a patient presenting with spinal tuberculosis, or “Pott’s disease”, with radiographic evidence of vertebral destruction.Site specific symptoms are often the catalyst for discovery of extrapulmonary sites of involvement.While the radiographic findings in this case may easily bring TB into the differential diagnosis for this patient, often with extrapulmonary disease, pertinent TB risk factors must be recognized by the astute clinician for TB to be considered and proper diagnostic testing (which include both culture and histopathologic sampling if available) be initiated.[Interactive option – Ask participants for their experiences with cases of extrapulmonary TB where the diagnosis was a surprise. What kind of sampling/testing for extrapulmonary disease is available to them in their practice? Any creative solutions to difficulties encountered in obtaining diagnostic samples or possibilities for shared resources?][Image credit: Francis J. Curry National Tuberculosis Center, University of California, San Francisco]
18 Standard 3: Extrapulmonary Specimens ISTC TB Training Modules 2009For 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.Standard 3 reinforces these points: [Read Standard 3]Clearly, appropriate specimens may be difficult to obtain from some extrapulmonary sites.In spite of the difficulties, however, the basic principle that bacteriological confirmation of the diagnosis should be sought still holds.Generally, there are fewer M. tb organisms present in extrapulmonary sites, so identification of acid-fast bacilli by microscopy in specimens from these sites is less frequent and culture is more important.If tissue biopsy material is obtained, diagnosis of TB may also be suggested by histopathologic demonstration of appropriate granulomatous lesions.[Instructor Notes: If the Microscopic Diagnosis module will not be covered in your curriculum, consider reviewing the Microscopic Diagnosis module for additional speaking points or slides that would be of interest for this topic.][Image credit: IUATLD
19 Clinical Presentation: Extrapulmonary ISTC TB Training Modules 2009Incidence/site may vary TB can involve any organMore common in HIV/TBBoth, 9%Extrapulmonary, 20%Pleural, 18%Lymphatic, 42%Extrapulmonary TB (without lung involvement) accounts for 15-20% of TB in populations with a low prevalence of HIV infection.In populations with a high prevalence of HIV infection, the proportion of cases with extrapulmonary TB is higher.[Click: Slide-show Animation]Here, as a general example, is the breakdown of extrapulmonary involvement by site as reported in the United States.[Review content of slide]Other, 13%Pulmonary, 71%Bone/joint, 11%Genitourinary, 5%TB Cases by Form of Disease,United States, CDC, 2008Peritoneal, 6%Meningeal, 5%
20 Extrapulmonary Tuberculosis ISTC TB Training Modules 2009Other examples of extrapulmonary presentations:Tuberculous pleural effusionCNS tuberculomas (two enhancing lesions seen on CT scan of head).Tuberculous adenitis (sometimes referred to as “scrofula”). Patient had both an enlarged anterior cervical node as well as a draining cutaneous fistula from supraclavicular nodes.[Image credits: Francis J. Curry National TB Center (left and top right); Austin Brewin, MD (bottom right)]
21 ISTC TB Training Modules 2009 Radiographic Presentation of TB[Image credit: Francis J. Curry National Tuberculosis Center, University of California, San Francisco]
22 Standard 4: Evaluation of Abnormal CXR ISTC TB Training Modules 2009All persons with chest radiographic findings suggestive of tuberculosis should have sputum specimens submitted for microbiological examination.While CXR examination can be a useful tool in the diagnosis of TB, remember that it is a sensitive, but not specific test for detecting TB.Key point: A diagnosis of TB cannot be established by radiography alone. Reliance on the chest radiograph as the only diagnostic test for TB will result in both over-diagnosis of TB and missed diagnosis of TB and other diseases.Thus, the importance of Standard 4: [Read Standard][Image credit: Francis J. Curry National Tuberculosis Center, University of California, San Francisco]ISTC Training Modules 2008
23 ISTC TB Training Modules 2009 Can this be TB?ISTC TB Training Modules 2009Typical Pattern: Reactivation, Post-primary TBDistributionApical / posterior segments of upper lobesSuperior segments of lower lobesIsolated anterior segment involvement is unusualCan this case be TB?[Click: Slide-show Animation]Yes - This is an example of a classic CXR pattern many would describe as a “typical pattern” or a reactivation/post-primary TB pattern.The distribution of disease is often cited as: [Review content of slide]Note that the presentation of an isolated upper lobe anterior segment infiltrate on CXR is unusual for M. tb, and may hint at another etiologic organism, perhaps a non-tuberculous mycobacterium (e.g. M. avium complex). The anterior segment of the upper lobe in this CXR is clear.[Interactive option – ask participants to respond to the question (this will likely illicit a quick “yes” response and will confirm what they know)][Image credits: Francis J. Curry National Tuberculosis Center, University of California, San Francisco]
24 Reactivation/Post-primary TB ISTC TB Training Modules 2009Patterns of diseaseAir-space consolidationCavitation, cavitary noduleMiliaryFibro-nodular densitiesNodule (Tuberculoma)Pleural effusionsSpecific radiographic patterns seen on CXR that may be associated with reactivation/post-primary TB include: [Review content of slide]This radiograph shows a small area of opacity with cavitation in the left upper lobe.[Image credit: Francis J. Curry National Tuberculosis Center, University of California, San Francisco]
25 ISTC TB Training Modules 2009 Can this be TB?ISTC TB Training Modules 2009Atypical pattern: Primary TBDistribution: Any lobe involved (slight lower lobe predominance)Air-space consolidationCavitation is uncommon (< 10%)Adenopathy is common (esp. in children and HIV)Miliary patternCan this case be TB?[Top CXR: Focal right mid-lung infiltrate with hilar adenopathy][Bottom CXR: Focal left lower lobe infiltrate][Click: Slide-show Animation]Yes, both of these patients had TB and represent examples of “atypical” patterns” of CXR presentation [Review content of slide].An “atypical pattern” may often be associated with Primary TB and also be commonly seen in patients with TB and HIV/AIDS co-infection.[Interactive option – ask participants to respond to question. There may be less certainty in participant response because these CXR findings are common for other infectious pneumonias.][Image credits: Francis J. Curry National Tuberculosis Center, University of California, San Francisco]
26 Can this be TB? Miliary TB ISTC TB Training Modules 2009Can this case be TB?[Automatic Slide-show Animation]Yes, these are all examples of the fine, stippled pattern of small nodules seen in miliary TB by chest radiograph (which correspond to the gross pathology demonstrating scattered granulomatous lesions seen on the right).This pattern of nodules, which reflects the hematogenous spread of disease, can also be appreciated well by chest CT imaging.Note that a miliary pattern may be seen in either primary or reactivation/post-primary disease.[Image credit: Francis J. Curry National Tuberculosis Center, University of California, San Francisco (left and center); University of California, San Francisco/Walter Finkbeiner, MD (right)]
27 ISTC TB Training Modules 2009 Can this be TB?ISTC TB Training Modules 2009Findings suggestive ofprior TBCa+ granuloma – Ghon lesionCa+ granuloma and hilar node calcification – Ranke complexApical pleural thickeningFibrosis and volume lossCan this case be TB?[Click: Slide-show Animation]Yes, these are examples of residual radiographic findings that can be found as the sequelae of prior active TB[Review content of slide]Note that the age and activity of disease cannot be determined by a single CXR.[Top: Ca+ granuloma and hilar node calcification - Ranke complex][Left: Apical pleural thickening][Right: Apical fibrosis with volume loss][Interactive option – ask participants to respond to question.][Image credit: Francis J. Curry National Tuberculosis Center, University of California, San Francisco]
28 ISTC TB Training Modules 2009 CXR IssuesISTC TB Training Modules 2009Reliance on chest radiograph alone results in both over-diagnosis and missed diagnosis of TB and other diseasesRadiography needs to be held to high standards of technical quality and interpretationResults of poor imaging quality may be harmful to patient careImportant issues regarding use of CXR for diagnosis of tuberculosis need to be considered: [Review content of slide].
29 Evaluation of Abnormal CXR ISTC TB Training Modules 2009Study from India:2229 outpatients evaluated by CXR/cultureOf 227 cases deemed TB by CXR alone36% had negative sputum cultures for TBOf 177 culture-positive cases of TB18% would have been missed based on CXR aloneCXR alone is not enoughOver-reliance on CXR without the use of sputum microscopy is a common practice in some areas.Data from a study done in a high-incidence country demonstrates just how misleading reliance on the CXR alone can be.[Review content of slide]Overall, radiographic examination for the evaluation of TB is most useful when applied as part of a systematic approach -- particularly, as we will discuss next, in the evaluation of persons whose symptoms and/or findings suggest TB, but who have negative sputum smears.[Reference: Nagpaul DR, Proceedings of the 9th Eastern Region Tuberculosis Conference and 29th National Conference on Tuberculosis and Chest Diseases Delhi, as cited in Toman’s tuberculosis. Case detection, treatment and monitoring, 2nd Edition. Freiden TR ed. Geneva: World Health Organization, 2004]Nagpaul DR, Proceedings of the 9th Eastern Region Tuberculosis Conferenceand 29th National Conference on Tuberculosis and Chest Diseases Delhi,as cited in Toman’s tuberculosis. Case detection, treatment and monitoring,2nd Edition: World Health Organization, 2004
30 Standard 5: Smear-negative Diagnosis ISTC TB Training Modules 2009The 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 tuberculosisLack 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.)The designation of “sputum smear-negative tuberculosis” presents a difficult diagnostic dilemma.On average, sputum smear microscopy is only about 50-60% sensitive when compared with culture.When clinical judgment suggests a high suspicion for TB, it is important that a rigorous approach be taken to evaluate fully for this diagnosis, despite the finding of three negative sputum smears.Standard 5 addresses the diagnosis of smear-negative TB. To diagnose smear negative TB, the following criteria should be met:[Read Standard][Note: Guidelines (WHO 2009 pending publication) have recently changed from three sputum smears to at least two sputum smears. The change is reflected above and differs from the wording in the original published ISTC.](1 of 2)
31 Standard 5: Smear-negative Diagnosis 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.Continued: [Read Standard](2 of 2)ISTC Training Modules 2008
32 TB Diagnostic Algorithm ISTC TB Training Modules 2009SPUTUM SMEAR-NEGATIVE TBClinical assessment, HIV test1, sputum smear microscopyAt least 2 sputum specimens AFB negativeHIV + and/or severe illness2A number of algorithms have been developed as a means to systematize the diagnosis of smear-negative TB, although none has been adequately validated under field conditions. In particular, there is little information or experience on which to base approaches to the diagnosis of smear-negative TB in persons with HIV infection when culture is not routinely available.Here, as an example of a systematic approach, is a composite algorithm modified from algorithms developed by WHO:Begin with the clinical suspicion for TB (TB Suspect).[Click: Slide-show Animation]. The most important first step toward making a diagnosis would be to obtain sputum for AFB microscopy. HIV testing is also of significant importance, particularly in areas of high HIV or TB/HIV prevalence .[Click: Slide-show Animation]. If at least two smears are negative, the next step takes into consideration HIV status and the severity of presentation. The algorithm continues on the next two slides.Note: This is one example of an algorithm that incorporates the fundamental principles recommended for diagnosing TB, and in practice, some local or national programs may follow a different sequence.Caution: First, it should be emphasized that the completion of all of the steps requires a substantial amount of time; thus, the algorithm should not be used for patients with an illness that is worsening rapidly. This is especially true in patients with HIV infection in whom TB may be rapidly progressive (as will be outlined on next slide).Second, several studies have shown that patients with TB may respond, at least transiently, to broad spectrum antimicrobial treatment. Such a response may lead to a delay in diagnosis of TB. Empiric fluoroquinolone monotherapy for respiratory tract infections has been associated with delays in initiation of appropriate anti-TB therapy and acquired resistance to the fluoroquinolones.Finally, following the above approach may be quite costly to the patient and deter her/him from continuing with the diagnostic evaluation.Given these concerns, application of such an algorithm in patients with at least two negative sputum smears must be done in a flexible manner.[Reference: World Health Organization. Treatment of tuberculosis. Guidelines for national programmes. Geneva: WHO 2003]HIV-, mild/moderate illness2Recommended in countries or areas with adult HIV prevalence >1% or prevalence among TB cases >5%Severe illness = respiratory rate >30 breaths/min, temperature >39°C, pulse >120 beats/min, unable to walk unaided, symptoms/signs progressing rapidly
33 TB Diagnostic Algorithm ISTC TB Training Modules 2009SPUTUM SMEAR-NEGATIVE TBHIV + and/or severe illnessRepeat clinical assessmentChest radiographSputum culture (or other test)Parenteral broad-spectrum antimicrobials (excluding fluoroquinolones)Clinical/radiographic findings NOT suggestive of TBNegative cultureClinical/radiographic findings suggestive of TBPositive or negative cultureIn HIV-positive or seriously ill patients the tempo of the evaluation and initiation of treatment must be accelerated. Empiric broad spectrum antibiotic treatment is recommended in seriously ill patients and empiric treatment for P. jiroveci pneumonia (PCP) should be considered if HIV-positive. One or more of the following danger signs would suggest that a patient is seriously ill: inability to walk unaided, respiratory rate over 30 breaths per minute, fever of more than 39 C, or pulse rate of over 120 beats per minute.Although, sputum smear microscopy is the first test of choice, culture should be included as an important step in evaluating cases of smear-negative suspects. Properly done, culture adds a significant layer of complexity and cost but also increases sensitivity , which should result in earlier case detection. Although the results of culture may not be available until after a decision to begin treatment has to be made, treatment can be stopped subsequently if cultures from a reliable laboratory are negative, the patient has not responded clinically, and the clinician has sought other evidence in pursuing he differential diagnosis.For seriously ill patients (particularly patients with HIV infection) a clinical decision to start treatment often must be made without waiting for the results of cultures. Such patients may die if appropriate treatment is not begun promptly.[Review contents of slide]It should be noted that even when the diagnosis is TB, patients may respond to a course of antibiotic treatment. As noted in Standard 5, the use of fluoroquinolones as empiric treatment for respiratory track infections may confuse the picture by causing a transient improvement of TB, and therefore should be avoided.[Reference: World Health Organization. Improving the diagnosis and treatment of smear-negative pulmonary and extrapulmonary tuberculosis among adults and adolescents. Recommendations for HIV-prevalent and resource-constrained settings. Geneva: WHO 2007]Not TBTBConsider other diagnosesTreat (empiric TB treatment before confirmed diagnosis if severe illness)HIV staging • Evalutate for ARVs • CPT prophylaxis
34 TB Diagnostic Algorithm ISTC TB Training Modules 2009SPUTUM SMEAR-NEGATIVE TBHIV–, mild/moderate illnessBroad-spectrum antimicrobials(excluding anti-TB drugs and fluoroquinolones)NO IMPROVEMENTIMPROVEMENTRepeat clinical assessmentChest radiographSputum culture (or other test)In patients who do not present with signs/symptoms of a serious level of illness, i.e. those considered ambulatory, or in those who are HIV-negative with non-severe illness, the evaluation may be managed along a somewhat different path.If the smears are negative and the initial clinical evaluation deems a diagnosis of TB unlikely, it is reasonable to give treatment for alternative diagnoses more time and fully assess the response before considering a re-evaluation for TB. [Review contents of slide]Again, obtaining cultures can be of key importance, particularly in smear-negative suspects who are not responding to empiric non-TB interventions.[World Health Organization. Improving the diagnosis and treatment of smear-negative pulmonary and extrapulmonary tuberculosis among adults and adolescents. Recommendations for HIV-prevalent and resource-constrained settings. Geneva: WHO 2007]Clinical/radiographic findings NOT suggestive of TBNegative cultureClinical/radiographic findings suggestive of TBPositive cultureNot TBTBNot TBConsider other diagnosisTreat
35 Clinical Presentation and Diagnosis of TB ISTC TB Training Modules 2009Additional points:Symptoms/severity: none to overwhelmingTempo of illness: ranges from indolent to fastTB can involve any organ or tissueSigns/symptoms may be both local and systemicConsider HIV testing in the diagnostic evaluationTB is capable of presenting in many waysWhile this lecture has reviewed many of the classic features of the clinical presentation of TB, it is worth repeating that it is a disease that may attempt to fool even the most astute clinician. A great range in presentation exists, especially if HIV is present (where atypical presentations are more common).One should remember: [Review content of slide][Click: Slide-show Animation]. Therefore it is important to realize that TB can present in many ways beyond the classic description. The ISTC offer guidelines to help prioritize our investigations in the initial recognition and diagnostic workup for TB.
36 Clinical Presentation and Diagnosis of TB ISTC TB Training Modules 2009Summary: Think TBA prolonged duration of cough should raise TB suspicion and trigger a diagnostic evaluationTB risk factors and exposure increase level of suspicionAFB smear in high-prevalence areas is highly specific and most rapid tool for diagnosing TBRadiographic patterns may help in TB diagnosis if suspicion high and AFB smear is negative, but a radiograph alone is not enough to make diagnosisTo summarize, the key points of this presentation were:[Review content of slide][Click: Slide-show Animation].And above all, Think TB.
37 Summary: ISTC Standards Covered* ISTC TB Training Modules 2009Standard 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.And in summary, the International Standards reviewed: (abbreviated)[Review content of slide][Click: Slide-show Animation].* Abbreviated versions
38 Summary: ISTC Standards Covered* ISTC TB Training Modules 2009Standard 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.[Continued - Review content of slide][Click: Slide-show Animation].[End]* Abbreviated versions
39 ISTC TB Training Modules 2009 Alternate SlidesAlternate Slides: Offer additional options that may be added or substituted into module.See Facilitator’s Guide for further information.
40 ISTC TB Training Modules 2009 Purpose of ISTCISTC Training Modules 2008ISTC TB Training Modules 2009The International Standards for Tuberculosis Care (ISTC):Are intended to unite public and private sectors in providing a uniformly accepted level of care for all patients with, or suspected of having, TB.Describes the essential elements of TB care that should be available everywhere.Provides a vehicle for mobilizing professional societies globally in support of TB programs.Serves as a powerful advocacy tool to ensure that the essential elements are available.[Image Credit: World Lung Foundation/Jad Davenport ]40
41 ISTC TB Training Modules 2009 ISTC: Key PointsISTC TB Training Modules 200921 Standards (revised/renumbered in 2009)Differ from existing guidelines: standards present what should be done, whereas, guidelines describe how the action is to be accomplishedEvidence-based, living documentDeveloped in tandem with Patients’ Charter for Tuberculosis CareHandbook for using the International Standards for Tuberculosis CareThe ISTC consist of 21 evidence-based standards. The original 17 standards from 2006 were revised and renumbered in 2009.Standards differ from existing guidelines in that standards present what should be done, whereas, guidelines describe how the action is to be accomplished.To meet the requirements of the Standards, approaches and strategies, determined by local circumstances and practices and developed in collaboration with local and national public health authorities, will be necessary. There are many situations in which the level of care can, and should, go beyond what is specified in the Standards.The Standards should be viewed as a living document that will be revised as technology, resources, and circumstances change. Revisions to the original document released December 2005 are currently underway.Funded (Oct 1, 2004) by USAID via TBCTA, development was supervised by an international steering committee (28 members / 14 countries) chosen to represent perspectives relevant to tuberculosis care and control.The Standards are also intended to serve as a companion to and support for the Patients’ Charter for Tuberculosis Care developed in tandem with the Standards.A Handbook for using the International Standards for Tuberculosis Care is also available (2007). The Handbook presents suggestions and guidance, based mainly on country-level experiences, for using the ISTC as a tool to foster and guide the delivery of high-quality care by all practitioners providing TB care.[Resource:
42 ISTC TB Training Modules 2009 ISTC: Key PointsISTC TB Training Modules 2009Audience: all health care practitioners, public and privateScope: diagnosis, treatment, and public health responsibilities; intended to complement local and national guidelinesRationale: sound tuberculosis control requires the effective engagement of all providers in providing high quality care and in collaborating with TB control programsThe Standards are addressed to all healthcare providers, private and public, who care for persons with proven tuberculosis or with symptoms and signs suggestive of TB.Three categories of activities are addressed by the Standards: diagnosis, treatment, and public health responsibilities of all providers. The ISTC are intended to be complementary to local and national TB control policies that are consistent with the World Health Organization (WHO) recommendations.In many parts of the world there is great variability in the quality of tuberculosis care, and poor quality care continues to plague global tuberculosis control efforts. Effective engagement of all providers in providing high quality care in collaboration with TB control programs is key to the promotion of sound tuberculosis control.
43 ISTC TB Training Modules 2009 QuestionsQuestions: May be used for interactive discussion, course evaluation, or continuing medical education purposes.See Facilitator Guide for further information.
44 Clinical Presentation and Diagnosis of TB ISTC TB Training Modules 20091. 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:Begin an empiric trial of treatment with a fluoroquinolone antibiotic for a possible community-acquired pneumoniaObtain a chest film to confirm your suspicion for TB which will make sputum testing unnecessaryObtain two sputum specimens for AFB microscopy (including at least one early morning specimen)Both answers A and CCorrect Answer: C
45 Clinical Presentation and Diagnosis of TB ISTC TB Training Modules 20092. In high prevalence areas, the AFB sputum microscopy smear:Is highly specific for TBIdentifies those at greatest risk of dying from TBIdentifies those most likely to transmit diseaseAll of the aboveCorrect Answer: D
46 Clinical Presentation and Diagnosis of TB ISTC TB Training Modules 20093. 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:An empiric trial of antibiotics (non-fluoroquinolone)Obtaining a chest film for further evaluationA trial of bronchodilator medication alone and follow-up in 3 monthsSending sputum specimens for AFB cultureCorrect Answer: C