BCR TBL 15 - Respiratory Infections

What is the primary function of alveolar macrophages?

Phagocytosis of inhaled pathogens and debris

Which class of antibodies is primarily involved in mucosal defense in the lungs?

Secretory IgA

Which cytokine activates macrophages in TB infection?

Interferon-gamma (IFN-γ)

What is the typical cell type found in viral pneumonitis?

Mononuclear inflammatory cells (lymphocytes)

Which pneumonia type is characterized by patchy inflammation of multiple lobules?

Bronchopneumonia

What is the first radiological investigation for suspected pneumonia?

Chest X-ray (CXR)

Which pneumonia has diffuse alveolar damage and hyaline membrane formation?

Viral pneumonia

What is the mechanism of action of neuraminidase inhibitors in influenza treatment?

Prevent release of new virions from infected cells

Which viral pneumonia presents with nonproductive cough and bilateral infiltrates?

Atypical viral pneumonia

What is a typical microscopic finding in fungal pneumonia?

Granulomas with fungal hyphae or spores

Which pathogen often causes pneumonia in patients with leukemia or lymphoma?

Aspergillus fumigatus

Which respiratory infection is notifiable by public health authorities?

Tuberculosis

Which structure traps particles in inhaled air before they reach the lungs?

Nasal turbinates and mucosa

What is the most common site of TB reactivation in the lungs?

Upper lobes

Which respiratory virus can cause myocarditis in addition to pneumonia?

Influenza virus

What is the pathophysiological reason for consolidation in bacterial pneumonia?

Alveolar spaces filled with neutrophils and exudate

Which condition impairs mucociliary clearance and predisposes to infection?

Primary ciliary dyskinesia

What condition is caused by Blastomyces dermatitidis?

Fungal pneumonia, Blastomycosis

What feature distinguishes fungal from bacterial pneumonia histologically?

Fungi are seen with special stains like GMS; bacteria are not

What is a common opportunistic lung infection after bone marrow transplantation?

Invasive aspergillosis

What is the significance of ground-glass opacities on a CT scan?

Associated with viral or fungal pneumonias (e.g., PCP)

Which test is used to confirm diagnosis of CMV pneumonia?

PCR or immunohistochemistry on tissue

What is the characteristic host cell finding in CMV infection?

Owl’s eye intranuclear inclusions

Which pneumonias commonly present with hemoptysis?

TB, Klebsiella, Aspergillosis

What infection risk increases after measles infection in children?

Secondary bacterial pneumonia

What is the key treatment principle for TB?

Multi-drug therapy for 6–9 months

Which infection is typically associated with droplet transmission?

Influenza virus

Which component of host defense is compromised in agammaglobulinemia?

Antibody production (B cells)

What respiratory pathogen is commonly associated with pet birds?

Chlamydophila psittaci

Which pathogen causes Q fever pneumonia?

Coxiella burnetii

What is the name of the histological lesion in primary TB?

Ghon complex

Which test is used to detect acid-fast bacilli in sputum?

ZN stain (Ziehl-Neelsen)

Which bacteria associated with pneumonia forms biofilms in the lungs?

Pseudomonas aeruginosa

Which diagnostic method is most specific for viral respiratory infections?

Nucleic acid amplification test (NAAT)

What is a key sign of pleural involvement in pneumonia?

Pleuritic chest pain and reduced breath sounds

Which bacteria is associated with cold agglutinin hemolytic anemia?

Mycoplasma pneumoniae

Which type of pneumonia may result from seizures or alcohol intoxication?

Aspiration pneumonia

Which respiratory infection requires airborne precautions in hospitals?

Tuberculosis

Which pneumonia is endemic to the southwestern US and known as “Valley fever”?

Coccidioidomycosis

What structure acts as the final barrier to alveolar infection?

Type I and II pneumocytes

Which part of the immune system is most important in defense against TB?

Cell-mediated immunity

Which test measures delayed-type hypersensitivity to TB antigens?

Tuberculin skin test (TST)

What complication is common in untreated pneumonia?

Empyema or lung abscess

Which viral pathogen can be shed in stool during respiratory illness?

Adenovirus

Which lung defense is enhanced by surfactant proteins A and D?

Opsonization and microbial clearance

Which bacteria has a polysaccharide capsule and causes meningitis and pneumonia?

Streptococcus pneumoniae

What is the role of ciliated epithelial cells in the airway?

Propel mucus and trapped particles out of the lungs

Which bacteria causes pneumonia after influenza due to protease activation?

Staphylococcus aureus

What is a major symptom differentiating typical vs atypical pneumonia?

Typical has productive cough; atypical has dry cough

Which pneumonia type shows interstitial rather than alveolar involvement?

Viral or atypical pneumonia

Which fungal infection causes spherules with endospores in tissue?

Coccidioides immitis

What type of pneumonia is associated with eosinophilia in tissue?

Eosinophilic pneumonia (e.g., parasitic)

What is the most common pathogen in ventilator-associated pneumonia (VAP)?

Pseudomonas aeruginosa

Which immune dysfunction increases risk of encapsulated bacterial pneumonia?

Splenectomy or functional asplenia

Which condition predisposes to recurrent lower respiratory tract infections?

Cystic fibrosis

Which TB complication results from hematogenous spread?

Miliary tuberculosis

Which test is used to monitor TB treatment response?

Sputum culture and microscopy

What organism can cause both pneumonia and meningitis in neonates?

Group B Streptococcus

Which virus has the potential to cause pneumonia and congenital infection?

Cytomegalovirus (CMV)

Which bacteria causes pneumonia with red currant jelly sputum and lung necrosis?

Klebsiella pneumoniae

Which fungal infection is most likely in HIV patients with CD4 <100?

Cryptococcosis

Which pathogen is known for branching septate hyphae at 45° angles?

Aspergillus species

What host defense is disrupted by smoking and air pollution?

Ciliary function

What is the primary site of entry for respiratory viruses?

Upper respiratory mucosa

Which lung structure contains surfactant-secreting cells?

Type II pneumocytes in alveoli

Which viral pneumonia is most likely in closed communities (e.g., military)?

Adenovirus

Which bacteria is detected via urine antigen test in pneumonia?

Legionella pneumophila

What symptom often indicates severe lower respiratory tract involvement?

Dyspnea

Which bacteria are most commonly associated with aspiration pneumonia?

Anaerobes (e.g., Bacteroides, Fusobacterium)

Which virus commonly causes pneumonia in patients with hematologic malignancies?

CMV (Cytomegalovirus)

What is the characteristic clinical triad of TB?

Fever, night sweats, weight loss

Which immune cells are depleted in HIV leading to PCP pneumonia?

CD4+ T cells

Which respiratory virus can cause otitis media as a complication?

RSV

What is the most common co-infection in influenza-related mortality?

Staphylococcus aureus

Which bacteria causes pneumonia and is also a common cause of otitis media?

Streptococcus pneumoniae

Which bacteria causes pneumonia in animal handlers and is zoonotic?

Coxiella burnetii

Which test is most sensitive for detecting COVID-19 pneumonia?

Real-time PCR (RT-PCR)

What is the incubation period for influenza virus?

1–4 days

Which pathogen causes pneumonia with mediastinal widening on CXR?

Bacillus anthracis

What is the most important vaccination for elderly to prevent pneumonia?

Pneumococcal vaccine

Which TB form involves lymph nodes, pleura, or bones?

Extrapulmonary tuberculosis

Which virus causes pneumonia and sometimes hemorrhagic cystitis?

Adenovirus

What bacteria is linked to pneumonia in patients with recent travel or water exposure?

Legionella pneumophila

What is the common route of spread in miliary TB?

Hematogenous dissemination

Which pneumonia can present with confusion and diarrhea?

Legionnaires’ disease

What diagnostic test detects fungal cell wall component β-D-glucan?

Serum beta-glucan assay

Which stain highlights encapsulated fungi in cerebrospinal fluid?

India ink

Which bacteria causes pneumonia with a rapid onset and pleuritic pain?

Streptococcus pneumoniae

What is a common symptom of atypical pneumonia?

Low-grade fever and dry cough

Which virus can cause pneumonia with bilateral perihilar infiltrates in neonates?

CMV

What test confirms diagnosis of Histoplasma pneumonia?

Urine or serum antigen detection

Which pathogen is found in moist environments and forms biofilms in lungs?

Pseudomonas aeruginosa

Which pneumonia causes upper lobe cavitation and sputum positivity for AFB?

Tuberculosis

What is the diagnostic feature of Nocardia pneumonia?

Filamentous, weakly acid-fast branching rods

What is a complication of untreated cavitary TB?

Bronchopleural fistula

Which part of the lung is most often affected in primary TB?

Lower or middle lobes (Ghon focus)

What is the most common cause of community-acquired pneumonia (CAP)?

Streptococcus pneumoniae

Which virus uses ACE2 receptors to enter host cells?

SARS-CoV-2 (COVID-19)

What is the main function of the mucociliary escalator?

To remove inhaled pathogens via ciliary movement and mucus

Which bacterium causes tuberculosis?

Mycobacterium tuberculosis