EXAM #1: DIAGNOSING GI INFECTIONS Flashcards
What is a the major host defense against esophagitis?
Motility
What are the typical pathogens that cause esophagitis?
1) Candida
2) HSV
3) CMV
What is the major host defense against gastritis?
Acidity
What is the typical pathogen that causes gastritis?
H. pylori
What are the typical pathogens that causes infectious diarrhea?
1) C. diff
2) E. coli
3) Salmonella
4) Shigella
What are the sx. of esophagitis?
1) Dysphagia
2) Retrosternal pain
3) Fever
Why is it important to determine if a patient has Candida cruzi?
This is resistant to the normal first line therapy (fluconazole)
What causes ulcerative esophagtitis?
1) HSV
2) CMV
You suspect a patient has infectious esophagitis; however, diagnostic work-up is negative. What should be next on your differential diagnosis?
GERD
What inclusion is associated with HSV?
asdf
How is candida esophagitis treated?
1) Oral fluconazole
2) IV echinocandin
or
Amphoterocin B
How is HSV esophagitis treated?
Acyclovir
How is CMV treated?
Valganciclovir or Ganciclovir
How is H. pylori non-invasively diagnosed?
1) Urea breath test*
2) Stool antigen test
If you have to do an endoscopy for H. pylori infection, what is the first choice test?
Biopsy urease test
How is H. pylori treated?
1) PPI + amoxicillin, then
2) PPI + clarithromycin + tinidazole
For patients that are allergic to clarithromycin, what should you do for H. pylori?
Quad therapy:
1) Bismuth subsalicylate
2) TCN
3) Metronidazole
4) Omeprazole
How long to you have to wait to re-test urea breath test and stool antigen s/p H. pylori treatment?
6-8 weeks
In taking a patient history, what is the most important feature to ask about when a patient has diarrhea?
Duration
- Less than 2 weeks= infectious
- More than 4 weeks= non-infectious
What is unique about the morphologic appearance of v. cholerae?
Curved* gram negative rod
What is C. perfringens highly associated with?
Home canned foods
What is Bacillus cereus highly associated with?
Rice
What is enterotoxigenic E. coli highly assocaited with?
Traveling to foreign countries
What is Salmonella highly associated with?
Caesar salad
What are the epidemiological clues that differentiate between Rotavirus and Norovirus?
Rotavirus= daycare Norovirus= nursing home/ cruise ship
What is Hepatitis A highly associated with?
Overcrowding
What organism is highly associated with swimming pools?
Cryptosporidium
How long does it take to get ill from a preformed toxin?
6-8 hours
How long does it take to get ill from an enterotoxin toxin?
8-72 hours
How long does it take to get ill from a cytotoxin?
Days
List the non-inflammatory diarrheas.
- V. cholerae
- Enterotoxigenic E. coli
List the inflammatory diarrheas.
- Shigella
- Salmonella
- Campylobacter jejuni
What is the difference between inflammatory and non-inflammatory diarrhea?
Non-inflammatory= watery (voluminous)
Inflammatory=
- Bloody/mucus
- Fever
- Positive fecal leukocytes
What is unique about E. coli O157:H7
- Inflammatory diarrhea (bloody) but no fever
- NO abx, may give patient HUS
Is it recommended to test stools of an asymptomatic patient for C. diff? What about for cure s/p treatment?
No- neither
What is emerging as the diagnostic of choice for C. diff?
PCR Toxin Gene Detection
If a patient has a positive endoscopy for PMC, do you need to do further testing?
No
How is C.diff treated?
1) Metronidazole
2) Vancomycin (more severe)
What route does Vancoymin need to be given for C. diff?
Oral, NOT IV
*Can be given as an enema if ileus with PMC
If a patient has chronic c. diff, what should you do?
- Normal regimen for first recurrence
- AFTER FIRST RECURRENCE, NO METRONIDAZOLE
- Vancomycin with second or later recurrence
Should probiotics be given to patients with recurrent C. diff?
No
When should you AVOID antiperistaltic agents in lower GI infections?
1) Fever
2) Bloody stool
