Approach to GI infections

Question 1

What are the host defenses that are associated with different areas of the GI Tract?

Answer 1

Esophagus- Motility/Aciidty
Stomach- Acidity/Motility
Small/Large Int- Normal Flora/motility

Question 2

What are the common clinical syndromes and pathogens that appear in each part of GI?

Answer 2

Esophagus- Esophagitis
Stomach-
Small/Large Int- ###

Question 3

What is common presentation of Esophagitis?

Answer 3

Dysphagia with or without odynophagia
Retrosternal pain
Candida- no ulcers
HSV 1- ulcerations, most common virus
CMV- Ulcerations, entire GI tract

Question 4

What are the Tx of common Esophageal microbes?

Answer 4

Candida: Oral Fluconazole, IV Echinocandin, or Ampho B
Herpes Simp: Acyclovir
CMV: IV Gancyclovir, Oral Valgancyclovir

Question 5

How is the somach infected by microbes?

Answer 5

Microbes neutrlize acid barrier
-inc enteric bacterial and parasitic inf.
-Inc normal flora in small bowel
H Pylori

Question 6

How is H Pylori Diagnosed Non-Invasively?

Answer 6

Non-invasive: Urea Breath Test, stool antigen, Serology

Question 7

How is H Pylori Diagnosed Invasively?

Answer 7

Invasive studies: Biopsy urease test(less sensitive when taking PPI or GI bleed), Histology, Culture

Question 8

What is the Tx of H. Pylori?

Answer 8

…

Question 9

What is the test for effective Tx of H Pylori?

Answer 9

Non-Invasive preferred
-Urea Breath test
-Stool antigen
(Not IgG Ab test)
Endoscopy

Question 10

What is Diarrhea?

Answer 10

A passage of abnormally liquid or unformed stools at increased frequency
acute: 4weeks

Question 11

What can fresh stool tell you?

Answer 11

Gross description: Watery, mucoid, bloody

Microscopic eval: Parasites, mal digested meat fibers, Lipid droplets

Question 12

What exposure is commonly seen with giardia infection?

Answer 12

Ingestion of stream water

Question 13

What exposure is commonly seen with Cryptosporidium infection?

Answer 13

Daycare centers, swimming pools

Question 14

What exposure is commonly seen with Entamoeba histolytica infection?

Answer 14

Travel to endemic areas

Question 15

What are the microbes that often give symptoms via preformed toxin?

Answer 15

Bacillus Cerus
S. Aureus
C. Perfringens

Question 16

What are the microbes that often give symptoms via Enterotoxin?

Answer 16

Vibrio Cholerae
ET E.Coli
Klebsiella pneumoniae
Aeromonas sp

Question 17

What are the microbes that often give symptoms via Cytotoxin?

Answer 17

C. Difficile

Hemorrhagic E. Coli

Question 18

What is the most common cause of identifiable antibiotic associated diarrhea?

Answer 18

C. Difficile

A and B toxin

Question 19

What is the most commonly used Abtx used for C. Diff?

Answer 19

Vancomycin and Metronidozol

Metro is used more than Vanco bc of Vanco Resistant enterococci

Question 20

What form of Vancomycin is used?

Answer 20

Oral Vancomycin does not penetrate the gut wall and keeps high concentrations of Drug in the gut lumen.

Question 21

WHat is the typical dose for high and low dose Abtx Treatment?

Answer 21

High: 500mg Metro PO TID
Low: 125mg Vanco PO QID

Question 22

What are treatments for recurrent C. Diff infections?

Answer 22

1st same regimen
No Metro past 1st recurrence or long term chronic therapy
2nd or later with vanco with taper or pulse therapy
Probiotics not recommended.

Question 23

What is the tx for lower GI tract infections?

Answer 23

Supportive including fluids and electrolytes
Bismuth subsalicylate or antiperistaltic if watery diarrhea(no fever or blood)
Pathogen specific Abtx when indicated.