GI tract infections Flashcards Preview

IDMM > GI tract infections > Flashcards

Flashcards in GI tract infections Deck (24):
1

C. difficile colitis
-epidemiology (risk factors, transmission)

Risk Factors: recent antibiotic use, recent hospitalization, long-term care facilities, older age, proton pump inhibitors
Transmission: fecal-oral

2

C. difficile colitis
-pathophysiology

Ab kill normal flora, C. diff overgrows, releases toxin A and B, mucosal injury and inflammation.
Pseudomembranes are formed

3

Ab most likely to lead to C. diff colitis

Clindamycin
Fluoroquinolones

But ALL can lead to it.

4

C. difficile colitis
-clinical presentation

- usually within 2 weeks of Ab therapy
-watery diarrhea
-elevated WBCs
-low grade fever
-in severe cases, fulminant colitis

5

C. difficile management

- Mild/moderate: metronidazole
-Severe: vancomycin (PO)

If neither gets better in 4-6 days, add the other.

6

Traveller's diarrhea
-likely etiology for acute onset, gradual onset/chronic, dysentery, one brief episode

Acute onset:
80-90% Bacteria
-ETEC and EAEC most common
10-20% Viral

Gradual onset/Chronic
-Giardia or Entameoba histolytica

Dysentery
-Salmonella, campylobacter, shigella

Brief episode
-preformed toxin food poisoning

7

Stool samples cansnd cannots

Can: shigella, campylobacter, salmonella, O&P
Cannot: distinguish ETEC/EAEC from normal E. coli, identify viral causes

8

Management of travellers diarrhea

1) identify the pathogen if symptoms are severe and persist >72hr
2) Rehydration fluid
3) Ab only for severe symptoms: fluoroquinolones, azithromycin
3) Don't use anti-motility agents unless you are using an Ab

9

Rotavirus
-epidemiology (infectivity, demographics)

- highly infectious (lots of virions passed, only need a few to infect)
-6-24 months weaning, developing world because they don't use vaccine

10

Rotavirus
-pathophysiology

- The virus infects and replicates in cells at the tip of villi in the small intestine.
-These cells die/are damaged
-Reduced absorptive capacity
-Intensely dehydrating

11

Rotavirus
-management

-Oral rehydration solution
-Zinc
-In some countries can give the ROTARIX vaccine to prevent the episode in the first place, but if you get it you have immunity usually

12

Hepatic abscess
-etiology

Amoebic liver abscess
-travel or from endemic area
-negative blood cultures
-anchovy paste aspirate

Bacterial liver abscess
-developed world
-biliary tract obstruction
-polymicrobial
-purulent aspirate
-postive blood cultures

13

Management of hepatic abscesses

Amoebic
-don't have to drain usually
-Metronidazole

Bacterial
-always drain
-Ab that cover G(-) bacilii, enterococci and anaerobes

14

Helicobacter pylori
-pathophysiology

- swims through mucus of stomch
-can neutralize stomach acid (urease)
-adheres to epithelial cells
-causes inflammation --> gastric or duodenal ulcer
-USUALLY ASYMPTOMATIC until ulcer or gastric cancer

15

Gastric ulcers
-etiology

70-80% H. pylori

16

Duodenal ulcers
-etiology

-90% H. pylori

17

Helicobacter pylori
-epidemiology (transmission, how common, demographics)

Transmission: fecal-oral
Most common bacterial infection in humans
More prevalent in older high socioeconomic status people

18

Helicobacter pylori
-Diagnosis of infection

Can be done for anyone with symptoms of gastric ulcers, cancer etc..

-Urease breath test
-serology
-stool antigen
-endoscopy+biopsy

***which one you choose depends on clinical situation and the pre-test probability**

19

Management of helicobacter pylori infection

HP-Pac
-Lansprazole, clarithromycin, amoxicillin

20

Oropharyngeal candidiasis
-Risk factors
-treatment

Risk: HIV+, infant, corticosteroid (e.g. asthma inhalers), post-antibiotic

Treatment:
Evaluate for HIV if >12mo
Nystatin swish and swallow
+/-
Clotrimazole troches
+/-
Fluconazole

21

Esophageal candidiasis
-risk factors
-treatment

Risk: already have oral thrush, HIV+, cancer, transplant

Treatment:
-systemic anti-fungals (fluconazole)

22

Hepatitis A,b,c risk factors

Hep A
-raw oysters
-contaminated food/water

Hep B, C
-sexual
-IVDU

23

Hep C treatment

pegylated interferon/ribivarin

24

Define:
diarrhea
gastroenteritis
enteritis
colitis
enterocolitis
dysentery
enteric fever

Diarrhea: abnormal liquid/unformed stool or at increased frequency.

Gastroenteritis: inflammation of stomach and sm intestines

Colitis: inflammation of the colon

Dysentry: pus+ blood in the stool with fever, low volume stools +/- cramping +/- vomiting

Enteric fever: diarrhea with blood stream invasion (=typhoid fever...don't need blood in the stool)