GI tract infections

Question 1

what is the main pathogen that causes esophagitis? what is the appearance?

Answer 1

candida albicans

white nonulcerative plaques

Question 2

what are the symptoms of esophagitis?

Answer 2

• dysphagia with or without odynophagia
• retrosternal pain
• fever (variant)

Question 3

treatment: candida

Answer 3

• oral fluconazole 14-21 days (preferred)

- IV echinocandin (effective) or amphotericin B (toxic)

Question 4

treatment: HSV

Answer 4

acyclovir

Question 5

treatment: CMV

Answer 5

• IV gangciclovir 3-6 weeks

- oral valganciclovir

Question 6

what are the noninvasive diagnostic tests for H. pylori?

Answer 6

• urea breath test
• stool antigen test
• serology (does not distinguish reliably between active and past infection)

Question 7

what are the invasive studies for H. pylori?

Answer 7

• biopsy urease test (first choice)
• histology
• culture

Question 8

standard treatment: H. pylori

Answer 8

• previously prescribed PPI
• clarithromycin
• amoxicillin

Question 9

what therapeutic options are used if the standard H. pylori regimen fails (sequential, alternate)?

Answer 9

sequential:
- rabeprazole + amoxicillin x5 days
- rabeprazole + clarithromycin + tinidazole x5 days

alternate:
- bismuth subsalicylate + TCN + metronidazole + omeprazole

Question 10

chronic diarrhea is diarrhea lasting how long?

Answer 10

over 4 weeks

Question 11

curved gram negative rod that causes diarrhea

Answer 11

vibrio cholerae

Question 12

swimming pool - risk of what infection?

Answer 12

cryptosporidium

Question 13

stream water - risk of what infection?

Answer 13

giardia

Question 14

which organisms causing acute diarrhea have a preformed toxin?

Answer 14

bacillus cereus

s. aureus
c. perfringens

Question 15

clinical presentation: non inflammatory diarrhea

Answer 15

large volumes
watery stools
s/s of dehydration

Question 16

clinical presentation: inflammatory diarrhea

Answer 16

dystentery - small quantities of blood and mucous, often with fever

Question 17

lab findings: non inflammatory diarrhea

Answer 17

• fecal leukocyte studies NEGATIVE
• acidosis
• azotemia

Question 18

lab findings: inflammatory diarrhea

Answer 18

fecal leukocyte studies positive

Question 19

which organisms causing acute diarrhea are cytotoxin producers?

Answer 19

c. difficile

hemorrhagic e. coli

Question 20

what is the most sensitive test for for epidemiological c. difficile studies? which one is used the most?

Answer 20

stool culture

PCR toxin gene detection (DNA molecular assay)

Question 21

what is the drug of choice for an initial episode of mild-moderate CDI?

Answer 21

metronidazole

Question 22

what is the drug of choice for an initial episode of severe CDI?

Answer 22

vancomycin

Question 23

what is the drug of choice for severe complicated CDI?

Answer 23

oral vancomycin with or without meteronidazole

Question 24

what are the treatments for lower GI infections?

Answer 24

• supportive (fluids, electrolytes)
• bismuth subsalicylate or antiperistaltic agents if watery diarrhea without fever or blood in stool (if appropriate)
• pathogen specific antibiotics when indicated

Question 25

what is a defining features of e. coli O:157 H7 / hemorrhagic diarrhea?

Answer 25

lack of fever