Infectious Disease & Public Health
Proctored Final Exam Review
(With Solutions)
2026
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,Multiple Choice Questions (MCQ)
A 58-year-old patient with chronic obstructive pulmonary disease
(COPD) presents with sudden fever, productive cough, and dyspnea.
Sputum culture identifies Pseudomonas aeruginosa. Which antibiotic
class is most appropriate considering resistance patterns?
a) Macrolides
b) Fluoroquinolones
c) Aminoglycosides
d) Penicillin
Answer: b) Fluoroquinolones
Rationale: Pseudomonas is often resistant to penicillin and
macrolides. Fluoroquinolones have good anti-pseudomonal coverage
and are frequently used in COPD exacerbations caused by this
organism.
In a public health outbreak of Clostridium difficile infections, which
infection control measure is most effective in preventing
transmission in a healthcare setting?
a) Use of alcohol-based hand sanitizer
b) Regular hand washing with soap and water
c) Universal masking of healthcare workers
d) Sterilization of all medical equipment with 70% ethanol
Answer: b) Regular hand washing with soap and water
Rationale: Alcohol-based sanitizers do not kill C. difficile spores
effectively. Soap and water are essential for physically removing
spores.
Which immunization strategy is the best example of herd immunity?
a) Vaccinating only healthcare workers during a measles outbreak
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, b) Mass vaccination of 95% of a population against influenza
c) Administering booster doses to elderly individuals only
d) Providing prophylactic antibiotics after exposure
Answer: b) Mass vaccination of 95% of a population against influenza
Rationale: Herd immunity occurs when sufficient proportion of a
population is immunized, reducing disease spread.
A patient presents to the emergency department with sudden onset
fever, confusion, stiff neck, and petechial rash. What is the highest
priority empiric antibiotic therapy?
a) Vancomycin and ceftriaxone
b) Amoxicillin alone
c) Ciprofloxacin
d) Azithromycin
Answer: a) Vancomycin and ceftriaxone
Rationale: This presentation suggests bacterial meningitis, often
caused by Neisseria meningitidis and Streptococcus pneumoniae.
Vancomycin and ceftriaxone cover the most common pathogens.
Which diagnostic test has the highest sensitivity in detecting latent
tuberculosis infection in HIV-positive patients?
a) Tuberculin skin test (TST)
b) Chest X-ray
c) Interferon gamma release assay (IGRA)
d) Sputum acid-fast bacilli smear
Answer: c) Interferon gamma release assay (IGRA)
Rationale: IGRA is less affected by BCG vaccination and
immunosuppression compared to TST.
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