TB

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Questions and Answers

What is the most common X-ray appearance of primary pulmonary tuberculosis?

Pleural effusion

Massive lung opacities

Fine 1–2mm lesions (correct)

Coarse consolidations

Which route of spread is NOT associated with miliary pulmonary tuberculosis?

Lymphatic spread

Airborne transmission (correct)

Blood-borne spread

Direct extension from the primary focus

Which symptom is least likely to be associated with advanced tuberculosis?

Exertional dyspnea

Severe abdominal pain (correct)

Anorexia

Night fever

What is a characteristic physical sign during the auscultation of a patient with advanced tuberculosis?

Widespread crackles Signup and view all the answers

Which of the following manifestations is NOT a common sign of tuberculosis?

Myocardial infarction Signup and view all the answers

What distinguishes post-primary tuberculosis from primary tuberculosis?

Progressive changes on radiograph Signup and view all the answers

What percentage of individuals exposed to Mycobacterium tuberculosis will develop tuberculosis disease?

10-15% Signup and view all the answers

What is the primary mechanism by which Mycobacterium tuberculosis is transmitted?

Person-to-person via droplets Signup and view all the answers

Which systemic involvement can indicate extra pulmonary tuberculosis?

Lassitude and easy fatigability Signup and view all the answers

Which of the following best describes post-primary tuberculosis?

Reactivation of a previously dormant infection Signup and view all the answers

Which of the following statements about the secondary spread of tuberculosis is accurate?

It can lead to renal and skeletal complications Signup and view all the answers

Which lymphocytic response is typically involved in the formation of a tuberculous granuloma?

Helper T-cells mediating inflammation Signup and view all the answers

Which clinical manifestation is associated with primary tuberculosis?

Asymptomatic without clinical signs Signup and view all the answers

What is a significant feature of the tuberculosis infection process in the lungs?

Formation of caseating granulomas Signup and view all the answers

What is the difference between Mycobacterium tuberculosis and Mycobacterium bovis in terms of infection routes?

MTB is airborne; M. bovis is through contaminated milk. Signup and view all the answers

What are the effects of immune system interaction with Mycobacterium tuberculosis?

It results in both primary and post-primary TB. Signup and view all the answers

What characterizes the location of the parenchymal component in primary tuberculosis?

Lower part of the upper lobe Signup and view all the answers

What defines post-primary tuberculosis?

It can arise from reactivation of a dormant primary lesion. Signup and view all the answers

Which statement about the fate of primary TB is true?

AFB can remain viable at the site of infection for a long period. Signup and view all the answers

What can occur as a reaction to exposure to foreign proteins from AFB in tuberculosis patients?

Allergic (hypersensitivity) reactions Signup and view all the answers

Which factor is most significant for the survival of the TB organism in post-primary TB?

High oxygen tension in peripheral lungs Signup and view all the answers

What is a common clinical manifestation of primary tuberculosis?

Limited symptoms or asymptomatic presentation Signup and view all the answers

What is indicated by the presence of a Ghon's focus on a chest x-ray?

Complete healing of primary TB Signup and view all the answers

What leads to the development of hilar lymphadenopathy in primary tuberculosis?

Lymphangitis connecting lung lesions Signup and view all the answers

Which of the following is NOT a complication associated with tuberculosis?

Atypical pneumonia Signup and view all the answers

Which of the following conditions is most likely to cause clubbing in a patient with tuberculosis?

TB bronchiectasis Signup and view all the answers

What is a hallmark symptom that might differentiate tuberculosis from atypical mycobacterial infection?

Caseating granulomas Signup and view all the answers

What method is utilized for the smear examination of tuberculosis to identify acid-fast bacilli?

Ziehl-Neelsen method Signup and view all the answers

Which of the following symptoms can indicate lower limb edema in a tuberculosis patient?

Right heart failure Signup and view all the answers

Which atypical mycobacterial species is mentioned as causing infections similar to tuberculosis?

M. scrofulaceum Signup and view all the answers

What is a potential diagnosis method for tuberculosis aside from bacteriological examination?

Histology of biopsy Signup and view all the answers

In which condition can the spread of tuberculosis lead to polyserositis?

Extrapulmonary dissemination Signup and view all the answers

What condition is a consequence of allergic reactions around the primary TB components?

Epituberculosis Signup and view all the answers

Which route of spread leads to the development of miliary TB?

Hematogenous spread Signup and view all the answers

What is a clinical manifestation that may indicate the presence of coexistent tuberculous meningitis?

Headache Signup and view all the answers

Which type of TB is characterized by bronchial obstruction leading to atelectasis?

Middle lobe syndrome Signup and view all the answers

What is likely to result from bronchial spread of primary TB?

Obstructive pneumonitis Signup and view all the answers

Which condition is NOT a manifestation of primary tuberculosis?

Miliary TB Signup and view all the answers

What results from the enlargement of lymph nodes around the middle lobe bronchus in children?

Middle lobe syndrome Signup and view all the answers

What symptom is commonly associated with miliary TB?

Night sweats Signup and view all the answers

What is the initial treatment strategy for active tuberculosis cases?

Start with 4 drugs for 2 months, then 2 drugs for 4 months Signup and view all the answers

Which drug is NOT recommended for pediatric use among the following?

Capreomycin Signup and view all the answers

Which assessment is essential for monitoring during tuberculosis treatment?

Visual disturbances Signup and view all the answers

What defines acquired drug resistance in tuberculosis treatment?

Resistance that develops due to inadequate treatment Signup and view all the answers

Which two drugs are highlighted as critical for the treatment of multidrug-resistant tuberculosis?

Rifampin and Isoniazid Signup and view all the answers

What is the recommended method for ensuring adherence to tuberculosis treatment?

Directly observed therapy (DOT) Signup and view all the answers

Which factor can lead to a false negative result in a tuberculin test?

Chemical denaturation of tuberculin Signup and view all the answers

What is a significant limitation of the IGRA test?

A positive result cannot differentiate between active and latent TB Signup and view all the answers

What is one of the primary purposes of patient isolation during the initial weeks of tuberculosis treatment?

To decrease the likelihood of disease transmission Signup and view all the answers

Which of the following drugs is commonly used in the treatment of tuberculosis?

Isoniazid Signup and view all the answers

What should be done if sputum or lymph node samples are not available and there is high clinical suspicion of tuberculosis?

Perform bronchoscopy to obtain bronchoalveolar lavage Signup and view all the answers

Which scenario best describes proper injection technique for the tuberculin test?

Injected intradermally to ensure accurate results Signup and view all the answers

What is the typical reason for using a mask in contact with a tuberculosis patient during treatment?

To avoid transmission of the bacteria Signup and view all the answers

What is a potential side effect of anti-tuberculosis drugs?

Liver toxicity Signup and view all the answers

What is the primary goal of tailoring treatment for MDR-TB?

To ensure the effectiveness of the treatment based on drug susceptibility Signup and view all the answers

Which combination is recommended for the treatment of MDR-TB?

One parenteral drug and two oral drugs to which the bacteria are fully susceptible Signup and view all the answers

What is the significance of a positive tuberculin test or IGRA in the context of TB treatment?

It signifies latent TB infection requiring treatment Signup and view all the answers

What is the primary purpose of administering the BCG vaccine?

To decrease the incidence of severe forms of TB such as military TB Signup and view all the answers

How should drugs for partially susceptible TB organisms be used in treatment regimens?

They should supplement the primary treatment regimen Signup and view all the answers

Which statement accurately distinguishes latent TB infection from active TB disease?

Latent TB infection results in a positive tuberculin test without symptoms and a normal chest X-ray. Signup and view all the answers

Study Notes

Primary Tuberculosis (TB)

Initial infection occurs in the lungs, tonsils, or intestines, leading to a reaction termed the primary complex.
Primary TB in lungs consists of a parenchymal component and hilar lymphadenopathy, developing within 4-6 weeks.
Symptoms are often minimal or absent during early stages.
Parenchymal lesions are typically located in the periphery of the upper or lower lobes.
Hilar lymph nodes may reduce, leading to calcified Ghon's focus visible on chest X-ray, indicating healing.
Reactivation of incompletely healed primary TB can lead to post-primary TB.

Post-primary Tuberculosis

Refers to a new (exogenous) infection or reactivation (endogenous) in sensitized individuals, often pulmonary.
Typically occurs at the apex of an upper lobe due to favorable oxygen conditions for Mycobacterium tuberculosis.
Onset is insidious, developing over weeks.

Tuberculosis Definition and Etiology

TB is a chronic bacterial infection caused by Mycobacterium tuberculosis, an intracellular pathogen.
Caseating granulomas form after exposure, characterized by central caseation, epithelioid cells, and Langhans giant cells.
Human Mycobacterium tuberculosis is the primary cause, with bovine Mycobacterium tuberculosis accounting for less than 1% of cases.
Only 10-15% of infected individuals develop active TB depending on immune factors.

Allergic Reactions to TB

Allergic responses can manifest as tuberculin hypersensitivity, erythema nodosum, pleural effusion, and epituberculosis.
Epituberculosis arises from allergic reactions around primary TB components, potentially compressing airways.

Routes of Spread of Tuberculosis

Bronchial Spread: Can lead to bronchogenic pulmonary TB, characterized by pneumonia, cavities, or nodular infiltration.
Lymphatic Spread: Can cause mediastinal lymphadenopathy; compression of bronchus can lead to atelectasis or bronchiectasis.
Hematogenous Spread: Results in miliary TB, presenting with fever, night sweats, and possibly affecting multiple organs.

Clinical Manifestations and Diagnosis

TB symptoms include cough (dry or productive), hemoptysis, chest pain, night sweats, and weight loss.
Physical signs may include signs of lung tissue consolidation, atelectasis, and effusion.
Diagnosis via smear or culture (sputum, CSF, biopsy), or histology showing caseating granulomas.

Diagnostic Investigations

Smear microscopy using the Ziehl-Neelsen method can detect acid-fast bacilli, requiring <5,000 AFB/ml for positivity.
Common chest X-ray findings include fine, millet seed-like lesions throughout lung fields.
Complete blood count may reveal anemia or leucopenia due to bone marrow involvement.

Differential Diagnosis

TB symptoms overlap with various respiratory diseases; need differentiation from atypical mycobacterial infections, especially in immunocompromised individuals.
Common atypical species include M. scrofulaceum, M. intracellulare, and M. fortuitum.

Management and Prevention

Effective TB management includes medications targeting Mycobacterium tuberculosis.
Preventive measures focus on infection control and minimizing exposure to TB bacilli.

Antitubercular Drugs and Their Toxicities

Kanamycin and Streptomycin share similar nephrotoxic effects, with implications on urea and creatinine levels.
Cycloserine can cause psychosis, personality changes, and convulsions as side effects.
Para Amino Salicylic Acid (PAS) is associated with gastrointestinal toxicity, hepatotoxicity, and skin rash indicated by elevated SGOT/SGPT levels.
Ethionamide exhibits toxicity similar to PAS.
Vancomycin has a toxicity profile that mirrors streptomycin.
Capreomycin has similar side effects to streptomycin but is contraindicated in pediatric patients.

Treatment Strategy for Tuberculosis

Multidrug regimens are required for all cases of active tuberculosis (TB).
Initial treatment includes four drugs: rifampin, isoniazid, pyrazinamide, and ethambutol for 2 months.
Follow up with rifampin and isoniazid for an additional 4 months; in some cases, treatment may extend up to 9 months.
Regimen adjustments should be made based on drug sensitivity.
Directly Observed Therapy (DOT) is recommended by WHO for treatment adherence.

Drug Resistance in Tuberculosis

Early unfavorable bacteriologic responses may indicate drug resistance, either primary from resistant strains or acquired through inadequate treatment.
Drug resistance can manifest as mono-resistance or multi-drug resistance, particularly against rifampin and isoniazid.
Multi-Drug Resistant Tuberculosis (MDR-TB) requires personalized treatment regimens based on culture and sensitivity tests.
At least three new drugs not previously administered are included in the regimen, ensuring combination therapy with direct observation.

Latent Tuberculosis Infection

Latent TB is characterized by a positive tuberculin skin test or IGRA without active symptoms or abnormal chest X-ray (CXR).
The presence of mycobacteria is minimal, with a competent host immune response.

Prevention and Vaccination

BCG vaccination, administered to 3-5 billion people, is part of the immunization program in Egypt for infants within their first three months.
BCG does not prevent TB infection but reduces severe forms, such as miliary TB and TB meningitis.

Tuberculin Test Considerations

Skin anergy may lead to false-negative tuberculin tests due to denaturation, improper storage, or incorrect administration technique.
Interferon gamma release assays (IGRA), including T-spot and QuantiFERON TB Gold, detect IFN-γ from T-cells in response to MTB antigens.
IGRA tests exhibit high sensitivity but low specificity; a negative indicates the absence of active or latent TB, while a positive cannot conclusively differentiate between the two.

Diagnostic Procedures

In cases of high clinical suspicion yet no sputum or lymph node sample, bronchoscopy and bronchoalveolar lavage (BAL) may be necessary.

Infection Control Measures

Patient isolation for the initial two weeks of treatment minimizes transmission risks.
Use of masks is essential during patient contact to reduce disease spread.

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Description

This quiz explores the characteristics and development of Primary Tuberculosis, focusing on the initial infection and its reaction in the lungs and regional lymph nodes. Learn about the parenchymal and glandular components, as well as the limited symptoms that accompany this stage of infection. Test your knowledge on the timeline and pathology of Primary TB.

TB

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