012015 diarrhea w infec

Question 1

clinical course of acute diarrhea

Answer 1

USUALLY SELF LIMITED

usually infectious, but even non-infectious causes will typically resolve

Question 2

etiology of small bowel infectious diarrhea

Answer 2

small bowel inflammed–leading to villous blunting, then malabsoprtion, then gut microbiome utilization of substrate, then abd cramping/bloating/gas/weight loss

cellular or intracellular leaking–mechanism similar to above

Question 3

fever is rare in small bowel infectious diarrhea-true or false

Answer 3

true

Question 4

infectious causes of infectious diarrhea

Answer 4

most gastroenteritis is viral

there’s also severe community acquired diarrhea (majority of which is bacterial)

Question 5

can get Salmonella typhi from

Answer 5

poultry, eggs, milk

pet turtles

Question 6

shigella

Answer 6

highly contagious

daycare settings

Question 7

why are antidiarrheal meds not used for infectious diarrhea?

Answer 7

b/c diarrhea is the body’s natural way of cleansing out pathogens

Question 8

most common bacterial infectious cause of diarrhea

Answer 8

campylobacter jejuni

Question 9

campylobacter jejuni

Answer 9

influenza like prodrome usually (fever, malaise, myalgias)

Question 10

campylobacter jejuni infectious diarrhea can present also with what other symptoms?

Answer 10

reactive arthritis, erythema nodosum (palpable, painful)

Guillain Barre syndrome

Question 11

like an appendicitis/RLQ pain

Answer 11

Campylobacter jejuni

Yersinia

Question 12

giardia lamblia

Answer 12

acute or chronic diarrhea
upper abdominal bloating
sm bowel disease

Question 13

E coli

Answer 13

colonize healthy GI tract-most are nonpathogenic but a subset cause human disease

Question 14

traveler’s diarrhea E coli

Answer 14

enterotoxigenic E coli (ETEC)

Question 15

pathogenesis of ETEC

Answer 15

expresses either heat labile toxin (similar to cholera toxin) or heat stable toxin (which increases cGMP with similar effects)

for heat labile toxin, cAMP causes secretion of Cl through its channel. prevents reabsorption of NaCl at villus tips. so you get net water secretion

Question 16

types of E coli diarrhea

Answer 16

ETEC
EIEC
EAEC
EHEC

Question 17

ATTACHES to enterocytes by adherence fimbriae

Answer 17

EAEC

Question 18

associated with hemolytic uremic syndrome (anemia, thrombocytopenia, uremia)

Answer 18

enterohemorrhagic E coli (EHEC)

Question 19

seafood associated disease (shellfish, plankton)

Answer 19

vibrio cholerae

Question 20

pathogenesis of vibrio cholerae

Answer 20

cholera toxin causes increased cAMP which opens CFTR to release Cl into lumen and draw water out

Question 21

norovirus is common in

Answer 21

adults

Question 22

rotavirus is common in

Answer 22

children

Question 23

which organism can cause pneumonitis?

Answer 23

ascaris lumbricoides (nematode)

Question 24

strongyloides

Answer 24

larvae live in fecally contaminated ground soil-can penetrate unbroken skin such as feet

migrate to lungs from which they are swallowed
mature into adult worms in intestines. eggs can hatch and release larvae that penetrate mucosa–AUTOINFECTION

Question 25

leading cause of iron deficiency anemia in the developing world

Answer 25

necator maericanus and ancylostoma duodenale (hookworms) they do autoinfection like strongyloides

Question 26

in immunocompromised hosts, what are they likely to get

Answer 26

cryptosporidium parvum MAC CMV

Question 27

nosocomial causes of diarrhea

Answer 27

C diff is really important

Question 28

proctitis

Answer 28

suggests rectal cause b/c the rectum is inflammed and in pain with stool there so you want to get it out

Question 29

waking up in the night

Answer 29

rectal cause

Question 30

gas/bloating

Answer 30

small bowel process of C diff

Question 31

hx of fever w diarrhea, think

Answer 31

``` invasive bacteria enteric viruses cytotxic organism (C diff or entamoeba histolytica) ischemia IBD ```

Question 32

why is scoping not helpful really for infectious colitis?

Answer 32

most bacterial infections all induce similar histopathology

Question 33

when should you do stool studies for infectious colitis?

Answer 33

do NOT do for acute and pt who looks good b/c disease is self limited ``` severely ill outbreaks requires hospitalization immunocompromised pts pts with comorbdities (IBD) employees may need the test to return to work ```

Question 34

ELISAs or DFA microscopy is used more or less commonly than stool test for ova and parasites?

Answer 34

more commonly

Question 35

indications for empiric antibiotics

Answer 35

fever, bloody diarrhea, and presence of occult blood or fecal leukocytes in stool (except for suspected EHEC or C diff) greater than 8 stools per day, volume depleted, hospitalized, immunocompromised

Question 36

C diff's virulence factors

Answer 36

toxins A, B | etc

Question 37

toxic megacolon

Answer 37

``` C diff (severe forms) it's a surgical emergency ```

Question 38

pseudomembranous colitis

Answer 38

C diff

Question 39

tx for C diff

Answer 39

vancomycin (inpt) and metronidazole (outpt)