3/21 Ch 13 Gastroenteritis Flashcards
RA = rapid associations ∆ = difference
1
Q
RA: mayo, custards, ham, poultry
A
staph aureus
2
Q
RA: fried rice, meat, vegetables, dried beans, cereals
A
bacillus cereus
3
Q
RA: beef, poultry, legumes, gravy
A
clostridium perfringens
4
Q
RA: shellfish
A
vibrio cholera
vibrio parahemolyticus
5
Q
RA: oysters, shellfish
A
vibrio parahemolyticus
6
Q
RA: salad, cheese, meat, water
A
ETEC
7
Q
RA: beef, poultry, eggs, dairy
A
salmonella
8
Q
RA: potato or egg salad, lettuce, raw veggies
A
shigella
9
Q
RA: improperly canned foods – bulging cans
A
c. botulinum
10
Q
RA: reheated meat dishes
A
c. perfringens
11
Q
RA: antibiotics
A
clostridium difficile
12
Q
RA: MSM
A
shigella (also giardia)
13
Q
RA: reptiles and amphibians
A
salmonella
14
Q
RA: turtles
A
salmonella enterica
15
Q
RA: proctitis
A
chylamydia, gonorrhea, syphilis, HSV
16
Q
RA: travel
A
ETEC
17
Q
∆ btwn acute, persistent, and chronic diarrhea?
A
diarrhea: 3 loose stools/24 hrs
acute: 10-14d
persistent: >14d
chronic: >30d
18
Q
RA: fever, severe abd pain
A
invasive disease
19
Q
RA: vomiting
A
toxin-mediated
20
Q
RA: abdominal bloating
A
outdoor exposures
21
Q
RA: dizziness
A
severe dehydration or chronicity
22
Q
RA: tenesmus
A
rectal inflammation (shigella, STDs)
23
Q
General etiology of non-inflammatory, inflammatory diarrhea and penetrating diarrhea?
A
Non-inflammatory (enterotoxin)
Inflammatory (invasion or cytotoxin)
24
Q
General etiology of non-inflammatory, inflammatory and penetrating diarrhea?
A
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
