Gastroenteritis

Question 0

Hx of gastroenteritis?

Answer 0

ask about ingestion of potentially contaminated food or water, travel, contact w/similarly ill person,medication use (abx use recently)

Question 1

What is gastroenteritis?

Answer 1

inflammation of lining of stomach, SI & colon (from infxns most commonly)
typically self-limiting but can be serious in young, elderly, immunocompromised

Question 2

Normal intestinal microflora? Where do you find the least amount of bac, why?

Answer 2

typically GI tract in habited by 500 different bac species

find least amount of bac in stomach & proximal small bowel b/c of acidity

Question 3

Ssxs of gastroenteritis?

Answer 3

character & severity vary

sudden onset of NV anorexia, abd cramps & diarrhea mb malaise & myalgia

Question 4

PE of gastroenteritis?

Answer 4

distended abd, enderness, borborygmi

Question 5

Possible w/u of gastroenteritis?

Answer 5

stool testing, CBC, CMP

Question 6

5 things that can cause gastroenteritis?

Answer 6

viruses, bacteria, parasites, fungal overgrowth & drug & chemical-related

Question 7

Viral gastro makes up what percentage of infectious diarrhea in US? What is viral gastroenteritis? What does it cause?

Answer 7

30-4% of infectious diarrhea in US
viruses infect enterocytes in SI villi= transudate of fluid/salt into lumen
cause watery diarrhea stools rarely contain blood or mucus

Question 8

What are the 5 types of viral gastro?

Answer 8

rotavirus, norovirus, astrovirus, enteric adenovrirus, CMV & enteroviruses in immunocompromised pts

Question 9

Occurence of rotavirus? When does it peak? Ssxs?

Answer 9

most common cause of infectious diarrhea worldwide
33% of hospitalizations & 20% of deaths assoc w/infectious gastroenteritis
highly contagious (fecal-oral route)
prevalent throughout yr peaks in winter
ssxs: vomiting, fever >102, sxs can last 5-7 d

Question 10

Who does norovirus affect & when? When can it become epidemic? contagious? Ssxs:?

Answer 10

older children & adults, year round
epidemic w/water & food-borne outbreaks
HIGHLY CONTAGIOUS
ssxs: acute onset vomiting, abd cramps, diarrhea, fever, HA, lasts 1-2 d

Question 11

Who does astrovirus usu infect? when? route? Ssxs?

Answer 11

infants & young kids
winter months
fecal-oral route
ssxs: acute onset vomiting, abd cramps, diarrhea, fever HA, lasts 1-2 d

Question 12

Who gets enteric adenovirus? when? route? ssxs?

Answer 12

kids <2 yo
year-round/summer
fecal-oral route
ssxs: diarrhea followed by mild vomiting, diarrhea that lasts 1-2 weeks

Question 13

3 mechanisms utilized by bacteria to cause gastroenteritis?

Answer 13

exotoxins, enterotoxins, mucosal invasion

Question 14

What is an exotoxin? what ssxs do they cause within how many hrs & sxs abate w/in how many hours? what is not in the stool?

Answer 14

toxin secreted by microorganism & released into enviro then ingested and causes N/V, watery diarrhea in 12 h of ingestion, sxs abate w/in 36 hrs, stools have no blood or WBCs

Question 15

4 bugs that utilize exotoxins to cause bacterial gastroenteritis?

Answer 15

stapholococcus aureus, bacillus cereus, clostridium perfringens, clostridium botulinum

Question 16

s. aureus gastroenteritis is usu caused by? common in what things? ssxs? course?

Answer 16

food poisoning w/toxin introduced by food-handlers
common foods involved: custard, milk products, potato salad, salad dressing, coleslaw, processed meat/fish at room temp
ssxs: sudden, abrupt, severe vomiting 2-6 hr post-ingestion, explosive diarrhea, abd cramps, rarely fever
course: 3-6 hrs, usu complete recovery

Question 17

Where doe sone find bacillus cereus? fcommon things to find contaminated? ssxs? course?

Answer 17

spore-forming organism in soil, contamination of food before cooking which survive high heat
common foods: contaminated rice or meat
ssxs: 2 distinct syndromes: emesis (2-6 hrs after ingestion severe vomiting, abd pain w/ or w/o diarrhea, afebrile, no systemic sxs) & diarrhea (8-16 hrs, foul smelling, profuse w/nausea, abd pain, tenesmus)
course: resolves in 12-24 hrs

Question 18

where do you find clostridium perfringens? most toxin synthesis occurs when? after ingestion of what things? ssxs? course?

Answer 18

spore-forming anaerobe in feces, soil, air, water
most toxin synthesized before ingestion, additional in GI
after ingesting contaminated beef, beef products, poultry, food inadequately pre-cooked & then reheated before served
ssxs: watery diarrhea, foul-smelling w/severe crampy abd pain, 8-16 hrs after ingestion
course: self-limited, resolves in 24-36 hrs

Question 19

clostridium botulinum has hat 3 eotoxin types? causes waht serious complication? what 2 types are assoc w/improperly prepared home-canned non-acidic fruits & veggies? what type assocaited w/smoked freshwater fish? doing what can inactivate exotoxin?

Answer 19

A, B, E
responsible for 1/3 OF DEATHS from food borne dz
A & B associated w/improperly prepared home-canned non-acidic fruits & veggies
E smoked freshwater fish
boiling in water for 15 min can inactivate exotoxin

Question 20

SSxs of clostridium botulinum?

Answer 20

incubation 4 hr- 8 d after ingestion
phase 1= vague, short period of fatigue, N/V, abd cramps, diarrhea
phase 2- visual, diplopia, decreased acuity, PERRLA, ptosis
phase 3- neuro, descending weakness or paralysis, dysarthria, dysphagia, weakness of trunk & extremities, sensorium unaffected normal or low temp, blood, urine, CSF normal

Question 21

course of c. botulinum?

Answer 21

65% mortality 29 d following ingestion, w/tx <10% supportive to prevent respiratory impairment

Question 22

ddx of c. botulinum gastroenteritis?

Answer 22

polio, encephalitis, M. gravis, curare, belladonna poisoning

Question 23

What is an enterotoxin? specific for what? impair what? cause what?

Answer 23

cytotoxin produced by bac, specific for mucous membrane of intestine (in vivo)
toxins impair intestinal absorption, increases secretion of water & electrolytes causing watery diarrhea

Question 24

What 3 bugs utilize enterotoxins to cause gastroenteritis?

Answer 24

cholera & non-cholera vibrio, enterotoxigenic escherichia coli & clostridium difficile

Question 25

where are cholear & non-cholera vibrio endemic? dt what? incubation? in US dt what? ssxs?

Answer 25

endemic in Asia any fecal contaminated water or food, in US from contaminated saltwater crabs & freshwater shrimp incubation 1-3 d after ingestion ssxs: sudden, painless, profuse, large volume, watery diarrhea, no blood or mucus, usu no fever, abd pain, vomiting, tenesmus, water & electrolyte loss leads to thirst, oliguria, muscle cramps, weakness, cold cyanotic skin, dehydration, hypotension, tachycardia

Question 26

Course of cholera & non-cholera vibrio?

Answer 26

recover in 7-10 d if rehydration is adequate, fatal in over 50% of untreated severe cases

Question 27

What does enterotoxigenic e.coli cause? route? incubation? ssxs?

Answer 27

diarrhea caused by tissue invasion or via its enterotoxin fecal/oral route of contaminated water or food, traveler's pathogen incubation: 1-3 d ssxs: profuse, watery diarrhea, 3-5 d

Question 28

How does c diff cause gastroenteritis? ssxs?

Answer 28

overgrowth of intrinsic organisms (post abx) or infxn by external source (soil, water, household pets) cytotoxin & enterotoxin cause pseudomembranous colitis commonly nosocomial dz, in hospital stay or nursing home or iatrogenic dz after abx use ssxs: watery diarrhea, cramping abd pain, N/V=RARE

Question 29

what is a complication of c. diff? Describe the complication. PE, W/U, complication of it? what procedure is contraindicated?

Answer 29

TOXIC MEGACOLON dilated colon w/fever, abd pain, tachycardia PE: tender abd, absent bowel sounds W/U: elevated WBC distended bowel on xray, colonoscopy is CONTRAINDICATED risks of: perforation, sepsis, septic shock other possible causes: UC, Crohn's, entamoeba histolytica, yersinia infxn

Question 30

What is mucosal invasion? what's in the stool? difference b/w watery & bloody stool?

Answer 30

ingested organism causes microscopic ulceration, bleeding, exudates, secretion of electrolytes & water stool has WBCs, RBCs, possibly gross blood, fever & prostration common, diarrhea may be watery or bloody watery: >1 L/d, usu no fever, HA, myalgia, arthralgia bloody: usu w/abd pain, tenesmus, N/V, fever, malaise

Question 31

what 5 bugs use mucosal invasion to cause gastroenteritis?

Answer 31

salmonella, campylobacter jejuni & fetus, shigella, enterohemorrhagic e. coli & yersinis enterocolitica

Question 32

Where do you find salmonella? sz of inoculum to make infection? ssxs? course?

Answer 32

ingestion of undercooked chicken or eggs, unpasteurized milk, contact w/reptiles large inoculum to produce infxn can cause exudative diarrhea or secretory ssxs: watery diarrhea more common, bloody may occur, ha, malaise, N/v, abd pain 6-48 hrs after ingestion may have fever course: usu self-limited to 7 d

Question 33

What is the most common bac cause of bloody diarrhea in the US? from what? incubation? ssxs? course?

Answer 33

cmapylobacter jejuni & fetus from contaminated pork, lamb, beef, milk products, water, infected pets incubation= 7-10 d ssxs: prodrome of HA, myalgia, malaise for 12-24 hrs then severe abd pain, high fever, profuse watery diarrhea, then bloody diarrhea course: usu self-limited to 7-10 d

Question 34

shigella occurs most commonly in what age? from what? contagious? ssxs?

Answer 34

children 6 mos-5 yrs food, water, milk can be contaminated, person to person HIGHLY CONTAGIOUS w/ very small incoculum ssxs: incubation 1-3 d, starts as lower abd pain, diarrhea, fever in 50%, many have biphasic illness starting as fever, abd pain, diarrhea, then 3-5 d rectal burning, tenesmus, small vol blood diarrhea course: variable- children resolves in 1-3 d, adults resolves in 1-7 d

Question 35

What is enterohemorrhagic e. coli? produces what toxin? from where? ssxs? course? complications?

Answer 35

e. coli 0157:H7 produces shiga toxin bovine reservoir, undercooked beef or unpasteurized milk, fecal-oral esp in daycare ssxs: acute onset of severe abd cramps, watery diarrhea >16hr after ingestion, becomes bloody w/in 24 hrs! course: 1-8 d if uncomplicated complications: HUS: hemolytic anemia, thrombocytopenia, acute renal failure & TTP: HUS, fever, neurological deficits

Question 36

Where do you get yersinia enterocolitica from? ssxs? what can it mimic?

Answer 36

undercooked pork, unpasteurized milk, contaminated water | ssxs: watery or bloody diarrhea & fever may mimic appendicitis if infxn in terminal ileum AKA acute ileitis

Question 37

What is traveler's diarrhea? what is the most common bac cause? most common viral cause? ssxs? onset? course?

Answer 37

gastroenteritis caused by contact w/organism endemic to locale visited usu contaminated water or food ingestion enterotoxigenic e.coli is most common also norovirus ssxs: N/V, borborygmi, abd pain/cramps, diarrhea onset: 12-72 hrs after ingestion course: usu self-limiting, fever & bloody diarrhea suggest more serious dz

Question 38

3 types of parasitic infxns that can cause gastroenteritis?

Answer 38

giardia lamblia, cryptosporidium parvus, entamoeba histolytica

Question 39

route for giardia? see in what pts especially? ssxs? course?

Answer 39

fecal-oral from contaminated water, person to person (daycare), traveler's pathogen esp in pts w/low IgA, hypochlorhydria, malnutrition, ingestion of cysts which break down releasing organism ssxs: incubation 7 d, mb asx, mild, watery diarrhea, abd bloating, cramps, flatulence for 1-3 wk, stools bulky, foul smelling course: mb self-limiting or infxn may persist & produce chronic or recurrent dz (celiac-like lesion causing lactose intolerance & malabsorption), fatigue, wt loss

Question 40

What pts usu have cryptosporidium? via what? sxs? in 2 types of pts sxs will be what?

Answer 40

high rate of infxn in HIV, immune-compromised, daycare via contaminated water, food, pets ssxs: in non-immune compromised pt- profuse, watery diarrhea, anorexia, low-grade fever 5 d after ingestion course: usu self-limited lasting ~2 wks in immune compromised pt- mb chronic, watery diarrhea up to 17/d, leads to dehydration

Question 41

Where do you get entamoeba histolytica from?

Answer 41

endemic, travel assoc, fecal-oral spread, in institutionalized pts HIV, AIDs, immune-compromised, cysts ingested, released leading to ulceration similar to IBD ssxs: if mild= crampy, abd pain, intermittent diarrhea; if severe- bloody diarrhea, abd pain, tenesmus, fever, toxic megacolon