PTB Flashcards
Which of the following is considered the most infectious form of pulmonary tuberculosis?
C: Cavitary TB
Which of the following conditions has the highest relative risk for developing active tuberculosis after infection with tubercle bacilli?
D: HIV infection
T/F. A person should maintain a distance of three meters from anyone who is symptomatic of TB.
F: False
The following are the clinical findings of Primary PTB Disease, except:
A: Symptomatic
The following are the clinical findings of Post-Primary PTB Disease, except:
D: Often abnormal chest PE
It is often seen in young children. (+) evidence of pulmonary TB in 50% cases. The neurologic symptoms are headache, fever, nuchal rigidity, irritability, and altered sensorium.
A: TB meningitis
It is straw-colored or sanguineous. Usually reflects primary disease. The PF analysis are exudative, high protein, and lymphocytic predominance.
C: Pleural TB
Which of the following is correctly matched:
B: Detecting Presence of Infection: X-ray
Which of the following statements is TRUE:
E: AOTA
If a patient has no risk factors for tuberculosis, what TST reaction size might the patient have?
C: TST ≥15mm
Which treatment category indicates CNS TB, TB of Bones or joints?
B: Category Ia
What is the etiologic agent of Tuberculosis (TB)?
Mycobacterium tuberculosis
What is the shape and structure of Mycobacterium tuberculosis?
Rod-shaped, non-spore-forming, thin and slender, aerobic, acid-fast bacilli
What is a unique structural feature of Mycobacterium tuberculosis that enhances its virulence?
Its cell wall has mycolic acids, arabinogalactan, and peptidoglycan, which reduce antibiotic effectiveness and enhance survival within macrophages.
How is TB primarily transmitted?
Through airborne droplet nuclei from a person with active TB, especially when coughing or sneezing.
What are the most infectious forms of TB?
Cavitary pulmonary TB and laryngeal TB
Which population has a higher TB incidence according to WHO’s 2019 report?
Males, and mostly in low- and middle-income countries
What increases the risk of TB reactivation?
HIV infection, which compromises the immune system
True or False: Cavitary pulmonary TB is less infectious than laryngeal TB.
False, cavitary TB is highly infectious, though laryngeal TB is also infectious.
What kind of immune response does TB primarily stimulate?
T-cell mediated immune response that leads to granuloma formation and caseous necrosis
How does TB infection begin in the body?
Tubercle bacilli enter macrophages in the lungs, where they can multiply if not destroyed by the immune system.
True or False: Latent TB infection has a low chance of reactivating in HIV-positive patients.
False, HIV-positive patients have a high risk of TB reactivation.
What diagnostic test is used to detect TB antibodies in the skin?
The Tuberculin Skin Test (TST) or Mantoux test
What is the primary mode of transmission for TB in crowded environments?
Airborne transmission through droplet nuclei that stay suspended in the air for hours
What social factor often leads to delayed TB treatment?
Stigma associated with the disease, causing people to seek private treatment instead of government health services.
In what type of environment is TB transmission more likely?
In poorly ventilated, crowded places such as dormitories or households with many residents
True or False: Tuberculosis is inherited.
False, TB is not hereditary but is transmitted from person to person.
What is a common symptom of TB due to lymphokine release?
Fever, malaise, anorexia, and weight loss
Which immune response directly contributes to tissue damage in TB?
Delayed hypersensitivity reaction, leading to caseating necrosis
What is the second leading cause of mortality worldwide?
Tuberculosis (TB), particularly in low- and middle-income countries
What is granuloma formation, and what triggers it in TB?
A host immune response where macrophages surround TB bacteria, often leading to caseous necrosis, triggered by T-cells.
Which diagnostic technique involves visualizing TB bacteria in sputum samples?
AFB Microscopy or Direct Sputum Smear Microscopy (DDSSM)
Which type of TB occurs outside the lungs?
Extrapulmonary TB, affecting organs like lymph nodes, pleura, and bones
How long can TB droplet nuclei remain airborne in a room?
Up to seven hours
True or False: Acid-fast bacilli like Mycobacterium tuberculosis can be stained with Gram stain.
False, M. tuberculosis does not stain with Gram stain but is acid-fast.
What is the approximate size of Mycobacterium tuberculosis?
0.5 to 3 μm
What is latent TB infection?
“Latent TB infection (LTBI) is a state where M. Tb antigens stimulate an immune response without active disease or symptoms. Patients with LTBI can be treated to prevent progression to active TB.”
What is the difference between latent TB infection and TB disease?
“Latent TB infection has no symptoms
What new evidence is there about latent TB infection?
“Bacilli form biofilms in necrotic areas
Should latent TB infection be treated?
“Yes
What is the most common symptom of pulmonary TB?
“Chronic cough. If ‘chronic cough’ is not an option
What are common symptoms of pulmonary TB?
“Night sweats
What is primary TB and who does it commonly affect?
“Primary TB occurs soon after infection
What are Ghon’s focus and Ghon complex?
“Ghon focus is the primary site of TB infection
What are typical findings in reactivation (secondary) TB?
“Symptoms include chronic cough
What are the signs of extrapulmonary TB?
“Extrapulmonary TB commonly affects lymph nodes
What is scrofula?
“A presentation of lymph node TB with painless swelling in the cervical and supraclavicular lymph nodes
What are the features of pleural TB?
“Pleural TB has straw-colored or bloody fluid
What is skeletal TB (Pott’s disease)?
“Skeletal TB affects weight-bearing joints
What is TB meningitis and who is at risk?
“TB meningitis is often seen in young children and adults with HIV. It presents with headache
What are symptoms of genitourinary TB?
“Urinary frequency
What are signs of gastrointestinal TB?
“Abdominal pain
What is pericardial TB?
“Pericardial TB presents with fever
What is miliary TB?
“Miliary TB results from hematogenous spread of TB
Q: What is the preferred radiographic examination for tuberculosis?
“A: Chest radiograph.”
Q: Where are infiltrates with cavitation commonly found in tuberculosis on a chest radiograph?
“A: In the upper and middle lobes of the lungs.”
Q: Are abnormal findings on a chest radiograph diagnostic for tuberculosis?
“A: No
Q: What are the sensitivity and specificity of a chest radiograph for detecting tuberculosis?
“A: Sensitivity - 87% ,Specificity - 89%
Q: What should be asked in a patient’s history when suspecting tuberculosis?
“A: Ask about history of TB.”
Q: What is the Xpert MTB/RIF assay used for?
“A: It is a diagnostic tool for TB with sensitivity of 85% and specificity of 98%. It detects TB and Rifampicin resistance.”
Q: What is the specimen requirement for Xpert MTB/RIF assay?
“A: Depends on the infected organ (e.g. if there is pleural TB (effusion) then, submit pleural fluid for Xpert MTB; if genitourinary TB then, urine is submitted; if lymphadenitis, then tissue.
Q: What molecular method does Xpert MTB/RIF use?
“A: Polymerase Chain Reaction (PCR).”
Q: What is the sensitivity range for AFB microscopy (DSSM)?
“A: 40-60%.”
Q: What staining method is used in AFB microscopy?
“A: Ziehl-Neelsen Stain.”
Q: What are the advantages and disadvantages of Ziehl-Neelsen Stain?
“A: Advantage - Cheap and easy to perform. Disadvantage - Requires 5000-10000 AFB/ml.”
Q: What is the gold standard for mycobacterial culture?
“A: Mycobacterial Growth Indicator Tube (MGIT) - WHO recommended.”
Q: How long does mycobacterial culture typically take?
“A: 10 days to 2-3 weeks with liquid media; 4-8 weeks with solid media.”
Q: What are advantages of mycobacterial culture over other TB tests?
“A: Higher specificity (~99%) and sensitivity
Q: What diagnostic tools are used for extrapulmonary tuberculosis?
“A: Fluid analysis
Q: What is the sequence of TB diagnosis?
“A: Sputum exam
Q: What does drug susceptibility testing assess in TB patients?
“A: Sensitivity to at least Rifampicin
Q: What factors may lead to a false negative TB result?
“A: Age
Q: What is the interpretation threshold for a tuberculin skin test (TST) reaction of ≥5mm?
“A: Positive in HIV-positive patients
Q: What is the adult daily dose for Isoniazid in TB treatment?
“A: 5 mg/kg
Q: What is the primary aim of TB treatment?
“A: To prevent morbidity and death
Q: How soon after starting TB treatment is bacterial activity reduced by 50%?
“A: Within the first 72 hours.”
Q: What is the standard treatment regimen for new pulmonary TB cases?
“A: 2 months of HRZE followed by 4 months of HR (2HRZE/4HR).”
Q: Why is HIV screening required before TB treatment?
“A: Due to potential impact on immune response and treatment success.”
Q: What does DOTS stand for?
“A: Directly Observed Treatment Strategy for tuberculosis.”
