Nosocomial infections

Question 1

Antibiotic use

Answer 1

• Clostridium difficile
• Watery diarrhea
• Leukocytosis

Question 2

Aspiration (secondary to altered mental status or old age)

Answer 2

• Polymicrobial, gram (-) bacteria, often anaerobes
• Right lower lobe infiltrate or right upper/middle lobe (patient recumbent)
• Purulent, malodorous sputum

Question 3

Decubitus ulcers, surgical wounds, drains

Answer 3

• S aures (including MRSA), gram (-) anaerobes (Bacteroids, Prevotella, Fusobacterium)
• Erythema, tenderness, induration, drainage from surgical wound sites

Question 4

Intravascular catheters

Answer 4

• S aureus (including MRSA), S epidermidis (long term), Enterobacter
• Erythema, induration, tenderness, drainage from access sites

Question 5

Mechanical ventilation, endotracheal intubation

Answer 5

• Late onset: P aeruginosa, Klebsiella, Acinetobacter, S aureus
• New infiltrate on CXR, increased sputum production
• Sweet odor (P aeruginosa)

Question 6

Renal dialysis unit, needlestick

Answer 6

• HBV

Question 7

Urinary catheterization

Answer 7

• E coli, Klebsiella, Proteus spp.
• Dysuria
• Leukocytosis
• Flank pain or costovertebral angle tenderness

Question 8

Water aerosols

Answer 8

• Legionella

- Signs of pneumonia, GI symptoms (nausea, vomiting), neurologic abnormalities, diarrhea, hyponatremia