Infectious Diseases

Question 1

A patient has sudden-onset diarrhea that lasts for a month. Ten other individuals manifest similar symptoms but have theirs last for 1 to 3 years. On work-up, there is subtle inflammation of the distal small intestine and proximal colon. There are no organisms seen on stool analysis. He was given metronidazole but without resolution. What is the likely diagnosis? (H20 C42 P263)
A.	Brainerd diarrhea
B.	Clostridium difficile
C.	Gastroparesis
D.	Rotavirus

Answer 1

Persistent diarrhea is commonly due to Giardia, but additional causative organisms that should be considered include C. difficile (especially if antibiotics had been administered), E. histolytica, Cryptosporidium, Campylobacter, and others. If stool studies are unrevealing, flexible sigmoidoscopy with biopsies and upper endoscopy with duodenal aspirates and biopsies may be indicated. Brainerd diarrhea is an increasingly recognized entity characterized by an abrupt-onset diarrhea that persists for at least 4 weeks, but may last 1–3 years, and is thought to be of infectious origin. It may be associated with subtle inflammation of the distal small intestine or proximal colon.

Question 2

Which vaginal infection is characterized by profuse, whitish or yellowish, homogenous vaginal discharge associated with vulvar itching? (H20 C131 P982)
A.	Bacterial vaginosis
B.	Chlamydial infection
C.	Trichomonal vaginitis
D.	Vulvovaginal candidiasis

Answer 2

The answer is C. Normal vaginal examination shows variable amount, usually scant, clear or translucent, nonhomogenous, flocculent vaginal discharge. Vulvovaginal candidiasis presents with scant, white, clumped discharge with adherent placques. Bacterial vaginosis presents with moderate, white or gray, homogenous, low viscosity discharge that uniformly coats vaginal walls.

Question 3

Which genital ulcer is characterized by multiple, 1-2 mm vesicles with erythematous edges that are frequently tender and with associated firm, tender bilateral lymphadenopathy? (H20 C131 P988)
A.	Chancroid
B.	Donovanosis
C.	Herpes
D.	Lymphogranuloma venereum

Answer 3

The answer is C.

Question 4

A 28-year-old female is admitted for leptospirosis. She is given ceftriaxone 1g IV 1x/day. On her 5th hospital day, she developed abdominal pain and frequent bowel movements of 10x/day, described as unformed mucoid stools. Labs reveal a WBC of 13 and creatinine of 90 mmol/L. Stool is positive for Clostridium difficile toxin. You give her oral metronidazole for 2 weeks. On follow-up 1 month later, she narrates that she has had watery diarrhea for the past 2 days, about 5x/day. She has no fever and CBC shows a WBC of 12, creatinine is normal. Which of the following is the most appropriate treatment? (H20 C129 P967)
A. Oral metronidazole
B. Oral vancomycin followed by a taper-and-pulse regimen
C. Oral vancomycin plus IV metronidazole
D. Rectal instillation of vancomycin

Answer 4

The answer is B. Recommended treatment options for first recurrence of CDI are Oral vancomycin (125 mg qid × 10 d), or Oral vancomycin followed by a taper-and-pulse regimen, or Fidaxomicin (200 mg bid × 10 d).