Wk 6 TBL 4 GI Infections

Question 1

Esophagitis

Answer 1

1. inflammatory process caused by infection
2. most often in immunocompromised
3. extent of damage related to severity of symptoms

Question 2

Causes of esophagitis

Answer 2

1. Candida (fungal) - often in immunocompromised, HIV
2. Herpesviruses
   a. CMV
   b. Herpes simplex virus
3. acid reflux
4. medication-induced (doxycycline)

Question 3

2 key clinical manifestations of esophagitis

Answer 3

1. odynophagia (pain on swallowing)
2. dysphagia (difficulty swallowing)

Question 4

Dx of esophagitis

Answer 4

empiric trial of fluconazole -> improvement -> assumed Candida esophagitis
2. endoscopy and biopsy

Question 5

Gastritis

Answer 5

1. can be erosive or nonerosive

Question 6

Define peptic ulcer disease

Answer 6

break in the gastric and adjacent duodenal mucosa

Question 7

What causes peptic ulcer disease

Answer 7

Helicobacter pylori

Question 8

Clinical presentation of gastritis

Answer 8

1. dyspepsia (epigastric pain, burning)
2. n/v
3. can be asymptomatic

Question 9

Pathogens associated w/ gastritis

Answer 9

1. H. pylori
2. CMV
3. Histoplasma capsulatum (fungi)
4. Mucor (fungi)
5. Anisakis (larvae after raw fish)
6. Mycobacteria (TB and nonTB)
7. Giardia
8. STronglyoides
9. EtOH
10. meds (NSAIDS)

Question 10

Dx gastritis

Answer 10

endoscopy w/ gastric biopsy
H. pylori confirmed w/ urease test or urea breath test or stool antigen test

Question 11

Tx of H. pylori gastritis

Answer 11

Quad therapy:
1. tetracycline
2. bismuth
3. metronidazole (or tinidazole)
4. PPI (omeprazole)
OR:
1. amoxicillin
2. clarithromycin
3. metronidazole (or tinidazole)
4. PPI

Question 12

Other names for diarrhea
Define acute and chronic

Answer 12

= gastoenteritis, enterocolotis
-Either acute (<2 wks) or chronic (>4 wks)

Question 13

What are 2 categories of acute diarrhea?

Answer 13

1. noninflammatory (watery, nonbloody)
2. inflammatory (bloody w/ pus) = dysentery

Question 14

4 Characteristics of watery diarrhea

Answer 14

1. No RBCs or WBCs in stool
2. typically afebrile
3. usually large-volume
4. infection typically sm intestine

Question 15

4 char of dysentery

Answer 15

1. RBC and WBC in stool
2. often febrile
3. usually small volume
4. infection typically colon

Question 16

9 organisms that cause watery diarrhea

Answer 16

1. ETEC
2. Vibrio cholerae
3. Staph aureus
4. Bacillus cereus
5. Listeria monocytogenes
6. Norovirus
7. Rotavirus
8. Giardia lamblia
9. Cryptosporidium hominis

Question 17

7 organisms that cause dysentery

Answer 17

1. STEC (Shiga toxin-producing E. coli)
2. Shigella
3. Salmonella
4. Campylobacter jejuni
5. Clostridioides difficile
6. Yersinia enterocolitica
7. Entamoeba histolytica

Question 18

What is the most common cause of acute diarrhea in the US?

Answer 18

Norovirus

Question 19

What is the second leading cause of diarrheal outbreaks?

Answer 19

Salmonella

Question 20

What is the most common cause of fatal diarrhea?

Answer 20

C. diff

Question 21

What MOA usually causes acute diarrhea?

Answer 21

1. preformed exotoxins in food
2. infectious agents in intestinal tract (via enterotoxin and cytotoxin production or mucosal invasion)

Question 22

What pathogens produce preformed exotoxins?

Answer 22

1. Staph aureus
2. Bacillus cereus
3. Clostridium perfringens

Question 23

What pathogens cause non-inflammatory acute diarrhea by enterotoxin production?

Answer 23

1. ETEC
2. Vibrio cholerae

Question 24

What 5 pathogens cause acute inflammatory diarrhea?

Answer 24

1. Salmonella
2. Shigella
3. Campylobacter (mucosal invasion)
4. Shiga toxin-producing E. coli (0157:H7)
5. C. diff (via cytotoxin production)

Question 25

What are risk factors for diarrheal illness?

Answer 25

1. PPIs 2. Recent travel to certain areas 3. Abx tx 4. Immunosuppressed have more frequent and severe diarrhea

Question 26

What pathogen is suspected if sx begins w/in 6 hrs after ingestion of contaminated food?

Answer 26

1. Staph aureus 2. Bacillus cereus (reheated rice)

Question 27

What can STEC in children progress to?

Answer 27

HUS = hemolytic uremic syndrome -occurs when Shiga-like toxin enters bloodstream

Question 28

What are the symptoms of HUS?

Answer 28

1. hemolytic anemia 2. thrombocytopenia 3. renal failure 4. schistocytes in blood smear

Question 29

What med increases the risk of HUS?

Answer 29

ciprofloxacin

Question 30

What causes severe, life-threatening watery diarrhea?

Answer 30

Vibrio cholerae

Question 31

What are the 2 most common causes of bloody diarrhea in the US?

Answer 31

1. Salmonella 2. Campylobacter

Question 32

What causes amebic dysentery?

Answer 32

E. histolytica

Question 33

When do we seek dx for diarrhea?

Answer 33

1. severe watery diarrhea 2. dysentery 3. patient is febrile 4. patient is elderly or immunocompromised

Question 34

What culture is used to detect STEC?

Answer 34

MacConkey-sorbitol agar -STEC does not ferment sorbitol

Question 35

What is a definitive dx technique for STEC/EHEC?

Answer 35

PCR immnoassay for Shiga-like toxin

Question 36

What can cause pseudomembranous colitis?

Answer 36

C. diff -yellowish pseudomembranes seen on colonoscopy

Question 37

Meds for mod-severe traveler's diarrhea

Answer 37

1. azithromycin

Question 38

Med for colitis caused by C. diff

Answer 38

oral Vancomycin

Question 39

Is there a vaccine for rotavirus?

Answer 39

Yes, 2 oral, live vaccines 1. live, attenuated Rotarix w/ most common strain 2. live reassortant Rotateq w/ 5 strains -rare, but intussusception reported with both

Question 40

What are some causes of appendicitis?

Answer 40

1. fecaliths 2. infections (parasites) 3. tumor -> increased luminal and intramural pressure -bacterial overgrowth occurs w/ inflammation -if necrosis is present, perforation can -> peritonitis

Question 41

Dx of appendicitis

Answer 41

abdominal CT w/ contrast