3/21 Ch 13 Gastroenteritis Flashcards Preview

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Flashcards in 3/21 Ch 13 Gastroenteritis Deck (95)
1

RA: mayo, custards, ham, poultry

staph aureus

2

RA: fried rice, meat, vegetables, dried beans, cereals

bacillus cereus

3

RA: beef, poultry, legumes, gravy

clostridium perfringens

4

RA: shellfish

vibrio cholera
vibrio parahemolyticus

5

RA: oysters, shellfish

vibrio parahemolyticus

6

RA: salad, cheese, meat, water

ETEC

7

RA: beef, poultry, eggs, dairy

salmonella

8

RA: potato or egg salad, lettuce, raw veggies

shigella

9

RA: improperly canned foods – bulging cans

c. botulinum

10

RA: reheated meat dishes

c. perfringens

11

RA: antibiotics

clostridium difficile

12

RA: MSM

shigella (also giardia)

13

RA: reptiles and amphibians

salmonella

14

RA: turtles

salmonella enterica

15

RA: proctitis

chylamydia, gonorrhea, syphilis, HSV

16

RA: travel

ETEC

17

∆ btwn acute, persistent, and chronic diarrhea?

diarrhea: 3 loose stools/24 hrs

acute: 10-14d
persistent: >14d
chronic: >30d

18

RA: fever, severe abd pain

invasive disease

19

RA: vomiting

toxin-mediated

20

RA: abdominal bloating

outdoor exposures

21

RA: dizziness

severe dehydration or chronicity

22

RA: tenesmus

rectal inflammation (shigella, STDs)

23

General etiology of non-inflammatory, inflammatory diarrhea and penetrating diarrhea?

Non-inflammatory (enterotoxin)

Inflammatory (invasion or cytotoxin)

24

General etiology of non-inflammatory, inflammatory and penetrating diarrhea?

Non-inflammatory (enterotoxin)

Inflammatory (invasion or cytotoxin)

Penetrating - they didn't really give a MoA...

25

location of non-inflammatory, inflammatory and penetrating diarrhea?

Non-inflammatory: Proximal small bowel

Inflammatory: Terminal Ileum, Colon

Penetrating: Distal small bowel

26

sx of non-inflammatory, inflammatory and penetrating diarrhea?

Non-inflammatory: watery (secretory)

Inflammatory: bloody or mucoid (dysentery)

Penetrating: Enteric fever (fever, chills, signs of bacteremia)

27

stool features of non-inflammatory, inflammatory and penetrating diarrhea?

Non-inflammatory Ø WBC

Inflammatory WBC (+), lactoferrin (+)

Penetrating WBC (+)

28

culprits of non-inflammatory diarrhea?

C. difficile
C.perfringens
ETEC
Giardia
Cryptosporidium
Vibrio cholera
Rotavirus
Norovirus
Bacillus cereus

29

culprits of inflammatory diarrhea?

Campylobacter
Entamoeba histolytica EHEC
EIEC
Salmonella (non-typhi)
Shigella
Y. enterocolitica
Vibrio parahemolyticus

30

culprits of penetrating diarrhea?

Salmonella typhi
Yersinia enterocolitica

31

when should you evaluate diarrhea complaints?ww

bloody
profuse w/ evidence of hypovolemia
small volume stools w/ blood and mucus
hospitalized patients
immunocompromised patients
pregnant patients
fever >38.5 (or evidence of systemic disease)
duration >48hrs or >6 stools/24hrs
diarrhea in the setting of recent antibiotic exposure

32

what test helps you differentiate between bloody and non-bloody diarrhea?

(+) Lactoferrin test (high sensitivity/specificity) = inflammatory diarrhea (indicates invasion or cytotoxin)

33

what tests can you run on a stool to determine the etiology of diarrhea?

Lactoferrin
Fecal WBC
stool cultures
Ova and Parasite (O+P)
PCR/Antigen test

34

When is endoscopy indicated?

- immunocompromised patients with ongoing sx and no clear etiology
- IBD suspicion
- ischemic bowel suspicion

35

is treatment indicated for regular diarrhea?

What treatments are generally used?

GENERALLY NOT INDICATED SINCE ITS SELF-LIMITED

but if you have to
- supportive (rehydration)
- antibiotics
- peptobismol
- loperamide

36

When are antibiotics indicated for diarrhea? which antibiotics are generally used?

fluoroquinolone or azithromycin

indicated for
- severe diarrhea (>8 episodes/day)
- prolonged diarrhea (>7 d)
- hospitalized patients
- immunocompromised patients

37

what is loperamide? MoA? When is it usually given?

µ opioid agonist that acts on the µ opioid receptors in the myenteric plexus of the large intestines only; decrease motility to allow for more H2O to be absorbed out of the fecal matter

given only when major infections have been ruled out

38

pathophysiology of Norovirus?

“viral gastroenteritis” Damages brush border and prevents reabsorption of H2O and nutrients

39

epidemiology and clinical presentation of Norovirus?

Epi: usually kids

Acute onset of vomiting (esp. in kids), low grade fever (30%)
abdominal cramps and/or non-bloody diarrhea (esp. in adults) within (10-48 hrs of exposure)

40

how to diagnose Norovirus?

PCR

41

treatment of Norovirus?

supportive

42

pathophysiology of rotavirus?

“viral gastroenteritis” Activated by proteolysis to infectious sub-viral particle that cause villous destruction and atrophy, leading to decr. absorption and incr. absorption of K

43

epidemiology and clinical presentation of rotavirus?

Main cause of pediatric diarrhea (3-15mo)

2 day incubation followed by watery diarrhea for 3-8. can be associated with fever and abdominal pain

44

how to diagnose rotavirus?

Rapid antigen test of stool

45

treatment of rotavirus?

Supportive
Vaccine available

46

pathophysiology of Shigella?

Invades and damages intestinal mucosa and causes PMN infiltration; resulting in superficial ulcerations, colitis with crypt abscesses

produces shiga toxin that inactivates 60S ribosome and enhances HUS.

47

epidemiology and clinical presentation of Shigella?

Children*
Fecal-oral
Daycare
Poor sanitation
MSM
(has human reservoir only)

12-72hr incubation, followed by dysentery, moderate to severe illness with fever and blood flecks in stool. lasts 1-2 weeks. Children can develop HUS due to Shigatoxin

48

how to diagnose Shigella?

Stool culture

49

treatment of Shigella?

Ampicillin
TMP/SMX and Ciprofloxacin for resistant strains
AVOID anti-motility agents

50

pathophysiology of Salmonella
(enteritidis, typhimurium)

Pili adheres to small intestines where enterotoxin stimulates fluid secretion and also stimulates a monocytic infiltration

51

epidemiology and clinical presentation of Salmonella
(enteritidis, typhimurium)

Eggs, poultry

12-26hr incubation: gastroenteritis with sudden onset of nausea, crampy abd. pain, diarrhea, and fever

52

how to diagnose Salmonella
(enteritidis, typhimurium)

Stool culture
Lactose (-)

53

treatment of Salmonella
(enteritidis, typhimurium)

Mild cases: supportive since abx may prolong fecal excretion of organism

Severe cases, immunocompromised, or extreme ages: TMP/SMX or ciprofloxacin

54

pathophysiology of Salmonella typhi (typhoid fever)

Penetrates mucosa of small bowel, carried to LN and blood with 2˚ excretion into intestines from bile

55

epidemiology and clinical presentation of Salmonella typhi (typhoid fever)

complications?

Found only in humans

10 d incubation; systemic illness with insidious onset of malaise, myalgias, HA, and high fever.
Classic rose spots on abdomen, diarrhea, temperature/pulse dissociation

Complications: intestinal perforation and chronic carriage in gallbladder

56

how to diagnose Salmonella typhi (typhoid fever)

Stool culture (only 80% diagnostic in early stage)

57

treatment of Salmonella typhi (typhoid fever)

Ampicillin
TMP/SMX
Ciprofloxacin
Vaccine - Live

58

pathophysiology of Campylobacter jejuni

Invasion of ileum and colon with inflammatory diarrhea

59

epidemiology and clinical presentation of Campylobacter jejuni

Animal reservoirs, poultry, unpasteurized milk

12-24 hr prodrome HA, myalgias, and fever, followed by acute diarrhea with >10 loose, non-bloody BM/day that lasts 5-7d

60

how to diagnose Campylobacter jejuni

Stool culture, grows at 42˚C
Oxidase +

61

treatment of Campylobacter jejuni

Controversial, but ciprofloxacin is effective in vitro

62

pathophysiology of EIEC

invade and cause cell destruction in the colon

63

epidemiology and clinical presentation of EIEC

Humans

Shigella-like diarrhea w/ fever; inflammatory

64

how to diagnose EIEC

Lactose fermentation (to differentiate from shigella)

65

pathophysiology of ETEC

colonization and production of enterotoxins that cause loss of H2O
LT  cAMP
ST  cGMP

66

epidemiology and clinical presentation of ETEC

Travelers and infants in developing countries or regions of poor sanitation

Milder, cholera-like watery diarrhea w/o fever

67

treatment of ETEC

Loperamide
fluoroquinolones
azithromycin (macrolide), rifaximin

68

pathophysiology of EPEC

adheres to intestinal mucosa and causes microvilli effacement; prevents absorption

69

epidemiology and clinical presentation of EPEC

Children in developing countries

Profuse, watery (sometimes bloody) diarrhea

70

diagnosis of EPEC

Toxins are not detectable in stool

71

treatment of EPEC

Antibiotics, resistance testing useful, possibly

72

pathophysiology of EHEC (0157:H7)

production of shiga-like toxin (Stx) that can cause HUS (anemia, thrombocytopenia, and acute renal failure)

73

epidemiology and clinical presentation of EHEC (0157:H7)

Poorly cooked beef,

Intense inflammatory response + necrosis, resulting in bloody diarrhea (hemorrhagic colitis); may progress to HUS

74

how to diagnose EHEC (0157:H7)

Agglutination test or immunoassay for shiga-like toxin

75

treatment of EHEC (0157:H7)

supportive care (antibiotics are contraindicated because it causes them to make more toxins; may lead to HUS)

76

what is EHEC (0157:H7) also known as

aka STEC

77

pathophysiology of Clostridium difficile

Anerotic toxin-producing bacteria

78

epidemiology and clinical presentation of Clostridium difficile

Pts on lots of antibiotics

4-9d incubation; Diarrhea + pseudomembranous colitis

79

treatment of Clostridium difficile

Metronidazole
Vancomycin for severe cases

80

pathophysiology of Yersinia enterocolitica

intracellular pathogen that cause mucosal ulcerations and mesenteric adenitis (inflammation of LN; causes attachment to abd wall)

81

epidemiology and clinical presentation of Yersinia enterocolitica

Animal reservoir with outbreaks from food and H2O, esp in daycare

Pseudo-appendicitis, diarrhea, and fever

82

how to diagnose Yersinia enterocolitica

Fecal isolation
(slow growth makes this difficult)

83

treatment of Yersinia enterocolitica

Tetracycline
TMP/SMX

84

pathophysiology of Vibrio parahemolyticus

Invasion + toxin formation

85

epidemiology and clinical presentation of Vibrio parahemolyticus

Undercooked seafood

24hr incubation; mild tissue damage with explosive watery diarrhea and low-grade fever

86

how to diagnose Vibrio parahemolyticus

Stool culture w. special media

87

treatment of Vibrio parahemolyticus

Supportive

88

pathophysiology of Vibrio cholera

Non-inflammatory toxin permanently activates Gs -> incr. cAMP -> incr. Cl secretion and H2O efflux in the gut

89

epidemiology and clinical presentation of Vibrio cholera

Food/water borne, seafood

1-2 d incubation; “rice-water diarrhea”, dehydration w/o fever

90

how to diagnose Vibrio cholera

1-2 d incubation; “rice-water diarrhea”, dehydration w/o fever

91

treatment of Vibrio cholera

Supportive
Tetracycline

92

pathophysiology of Listeria monocytogenes

Intracellular pathogens that pass through the intestines into macrophages and causes disseminated infection

93

epidemiology and clinical presentation of Listeria monocytogenes

Coleslaw, dairy, cold processed meats
Immunocompromised, extreme ages, pregnant women

94

how to diagnose Listeria monocytogenes

2-6 wk incubation: fever, myalgias, bacteremia, meningitis

95

treatment of Listeria monocytogenes

Blood or CSF culture