Physician Assistant Infectious Diseases 5

Question 1

An IV drug user has fever and a new murmur, and echocardiography shows a tricuspid valve vegetation. What is the most likely organism?

Accepted Answer

Staphylococcus aureus

Answer

S. aureus is the most common cause of endocarditis in people who inject drugs, and it often involves the tricuspid valve.

Question 2

Blood cultures grow Streptococcus gallolyticus (formerly S. bovis) in a patient with endocarditis. What additional evaluation is indicated?

Accepted Answer

Colonoscopy

Answer

S. gallolyticus bacteremia is strongly associated with colorectal neoplasia, so colonoscopy is warranted.

Question 3

What is the appropriate empiric antibiotic regimen for suspected bacterial meningitis in a 65-year-old?

Accepted Answer

Vancomycin, ceftriaxone, and ampicillin

Answer

Adults over 50 need ampicillin added for Listeria coverage on top of vancomycin plus a third-generation cephalosporin.

Question 4

A patient from Arizona has a community-acquired pneumonia-like illness, erythema nodosum, and arthralgias. What is the most likely organism?

Accepted Answer

Coccidioides immitis

Answer

Coccidioidomycosis (valley fever) is endemic to the Southwest and often presents with pneumonia, erythema nodosum, and arthralgias ('desert rheumatism').

Question 5

A diabetic patient has severe pain disproportionate to the exam, rapidly spreading erythema, crepitus, and hemodynamic instability. What is the most important next step?

Accepted Answer

Emergent surgical debridement plus broad-spectrum antibiotics

Answer

Necrotizing fasciitis is a surgical emergency, and imaging must not delay debridement and broad-spectrum IV antibiotics.

Physician Assistant Practice Test

Physician Assistant Practice Test

Physician Assistant Infectious Diseases 5