Infections of the GI tract (Schoenwald) Flashcards
1
Q
Is infectious diarrhea acute or chronic in onset?
A
Acute
2
Q
How long does infectious diarrhea last for?
A
Lasts less than 2 weeks
3
Q
What should be part of the history in patients with infectious diarrhea?
A
Travel history
4
Q
What suggests a viral etiology of infectious diarrhea?
A
Community outbreaks in nursing homes, schools, cruise ships, or common food source
5
Q
Watery, non-bloody diarrhea is characteristic of what kind of diarrhea?
A
Non-inflammatory
6
Q
What are the sxs of non inflammatory diarrhea?
A
Cramping, bloating, nausea, vomiting- disrupts normal absorption in the small bowel
7
Q
Will you see fecal leukocytes on a smear in non-inflammatory diarrhea?
A
No, no fecal leukocytes will appear on the smear because tissue invasion does not occur in non inflammatory diarrhea
8
Q
What types of diarrhea accompanies fever and bloody diarrhea
A
Inflammatory
9
Q
What type of diarrhea will you have colonic tissue damage from invasion of bacteria or toxin?
A
Inflammatory diarrhea, which is why it is bloody
10
Q
What part of the colon is primarily involved in inflammatory diarrhea?
A
Lower colon
11
Q
What sxs will you see in inflammatory diarrhea?
A
Lower quadrant cramping, urgency
12
Q
Will there be fecal leukocytes present in inflammatory diarrhea?
A
Yes, because of invasion of mucosa
13
Q
What should your differential include when diagnosing inflammatory diarrhea?
A
Ulcerative colitis
14
Q
Diarrhea lasting longer than 14 days is most likely…
A
NOT due to an infectious agent (except c diff!)
15
Q
What is the major difference between inflammatory and non inflammatory diarrhea?
A
Colonic tissue invasion by the organism and/ or toxin
16
Q
Why is it important to classify the diarrhea as inflammatory vs non inflammatory?
A
Helps to differentiate when it is “okay” to use anti motility agents such as Imodium
17
Q
What is Imodium?
A
Anti motility agent- helps with diarrhea
18
Q
When should you absolutely not use antimotility agents?
A
In inflammatory diarrhea- this traps the organism in the colon, causing more damage, perpetuating the sxs, and prolonging the infection
19
Q
What are some typical stool pathogens?
A
Salmonella Shigella Campylobacter Vibrio E Coli O157:H7 Clostridium difficile Norovius Enterovirus Parasites- giardia, amoeba, cryptosporidium
20
Q
What organism should you suspect with previous antibiotic usage?
A
Cdiff
21
Q
What causes non inflammatory diarrhea?
A
Enterotoxin production- Staph aureus B cereus Enterotoxigenic E. coli Vibrio cholerae
& Norovirus Rotavirus Giardia Cryptosporidium Listeria monocytogenes
22
Q
What causes inflammatory diarrhea?
A
Cytotoxin production... Enterohemorrhagic E. coli 0157:h7 C diff Mucosal invasion... Campylobacter Shigella Salmonella
Cytomegalovirus
Entamoeba histolytica
23
Q
What agents cause enterotoxin production in non-inflammatory diarrhea?
A
Staph aureus
Bacillus cereus
Enterotoxigenic E. coli
Vibrio cholerae
24
Q
What agents cause cytotoxin production in inflammatory diarrhea?
A
Enterohemorrhagic E. coli 0157:H7
C diff
25
What agents cause mucosal invasion in inflammatory diarrhea?
Campylobacter
Shigella
Salmonella
26
What is the new name for C diff?
Clostridioides difficile
| Previously clostridium difficile
27
What agents cause inflammatory diarrhea?
```
C diff
Salmonella
Shigella
Campylobacter
E. coli 0157:h7
```
28
What is the main symptom in a c diff infection?
Diarrhea
29
What are the major risk factors to an infection with c diff
Previous antibiotic usage
Advanced age
Previous hospitalization
Nursing home resident
30
What antibiotics are known for causing a c diff infection
Clindamycin
Penicillins
Cephalosporins
Fluroquinolones
31
What makes the diagnosis under the new guidelines for c diff?
Presence of symptoms in the form of three or more unformed stool over 24 hours for 2 consecutive days in conjunction with positive stools for pseudomembranes
Prior antibiotic usage in not included in making the diagnosis with the new guidelines
32
What are the clinical findings in a c diff infection?
```
Water diarrhea
15-30 bowel movements per day
Abdominal pain or cramps
Low grade fever
Can lead to toxic mega colon and Colectomy
```
33
What are the lab findings in c diff?
Leukocytosis- often with bandemia (left shift)
Hypoalbuminemia
Positive stool c diff test
34
What are the lab tests for c diff?
Molecular test- PCR
Antigen detection
Toxin testing
35
What lab test for c diff is highly sensitive and specific and can be positive in asymptomatic patients?
Molecular test PCR
36
Which lab test for c diff is nonspecific?
Antigen detection
37
Which lab test for c diff is associated with high rates of false negatives?
Toxin A and B testing, used for screening
38
For an initial episode of c diff that is mild/moderate what do you expect to see on labs?
Leukocytosis <15,000, creatinine <1.5
39
For an initial episode of c diff with mild to moderate symptoms, what should you use to treat?
Vancomycin 125mg po qid X 10 days OR
| Fidaxamin 200 mg po bid X 10 days
40
For an initial episode of c diff that is severe, what labs would you expect to see?
Leukocytosis >15,000, creatine >1.5 prior to CDI
41
For an initial episode of c diff with complications, what clinical signs will you see?
Hypotension
Shock
Perforation
Megacolon
42
What should you use to treat an initial episode of c diff that is complicated?
Vancomycin 500mg po qid or via NG tube and or metronidazole 500-750 mg IV q 8 hours
43
What should you use to treat the 1st recurrence of c diff?
Vancomycin oral taper or Fidaxamin 125mg po qid
44
What should you use to treat a 2nd recurrence of c diff?
Vancomycin oral taper or Fidaxamin
| Fecal mircobiota transplant
45
What can be done to prevent c diff infections?
Antibiotic stewardship
| Environmental control, hand hygiene
46
When wanting to prevent c diff, it is important to remember that spores can live up to ___ months on a surface
5
47
When thinking about preventing a c diff infection, it is important to remember that _____ can be a vector
Health care workers
48
Are alcohol hand preps effective for preventing c diff?
No
49
What should be used on surfaces to prevent the transmission of c diff?
Chlorine based disinfectants
50
Salmonella is a gram negative/ positive rod
Gram negative rod
51
Salmonella is carried in the GI tract of....
Reptiles and birds
52
How many cases of salmonella infections yearly in the US?
3.7 million
53
How do most cases of salmonella occur?
From eating contaminated meat or eggs or from infected food handlers
Also associated with handling reptiles
54
Patients with a salmonella infection can remain culture positive for ___ months after treatment, making them a long term carrier
1 month
55
How long is the incubation for salmonella?
6-48 hours
56
What are the clinical sxs of salmonella?
Fever and diarrhea most common sxs
Usually self limited
Bloody stools uncommon
57
Where can salmonella spread to?
Vascular grafts, joints, kidneys and liver common in bacteremic patients
58
What is the treatment of salmonella?
Most cases are self-limiting, if uncomplicated no antibiotic treatment is necessary
Ciprofloxacin treatment of choice
Bactrim (trimeth/sulfa) alternate
59
What agent causes typhoid fever?
Salmonella typhi
60
What is important to making the diagnosis of typhoid fever?
Typhoid fever is NOT endemic to the US- travel history is vital for diagnosis
61
Where are high risk areas for typhoid fever?
India
Pakistan
Caribbean
Mexico
62
How is typhoid fever transmitted?
By contaminated food, sewage, and infected food handlers (could be asymptomatic carriers)
63
What are the symptoms of typhoid fever?
```
Diarrhea
Constipation
Skin rash on torso and back
Fever
Abdominal pain
Weakness
```
64
How is the diagnosis of typhoid fever made?
Stool culture
65
What is the treatment for typhoid fever?
Antibiotic resistance is an issue
Historic treatment is fluoroquinolones- cipro
Ceftriaxone resistance is developing
Due to resistance issues, current recommendation is azithromycin for mild, carbapenems for more severe cases with history of travel to SE Asia
66
What is the prognosis of typhoid fever?
It is a serious infection that can be fatal, especially if ineffective treatment due to antibiotic resistance
67
Shigella is a gram...
Gram negative rod
68
What organism is commonly referred to as "dysentery" ?
Shigella
69
Carriers of shigella are symptomatic/asymptomatic
Asymptomatic
70
Is shigella virulent?
Yes, only 10-100 organisms can cause infection
71
How is shigella spread?
Person to person
| Fecal to oral spread, also flies and inanimate objects
72
How many worldwide deaths per year can be attributed to shigella?
650,000 deaths worldwide
73
What is the incubation period for shigella?
12 hours to 4 days
74
What are the symptoms of shigella?
```
Diarrhea that is bloody, watery, pus and mucus- secretory
Fever
Stomach cramps
Nausea
Vomiting
Dehydration
```
75
What should be on your differential when making the diagnosis of shigella?
Other bacterial infections such as vibrio
Viral
Parasites
76
What is the treatment for shigella?
Rehydration
Ciprofloxacin
Bactrim or azithromycin alternate (recent strains show high rate of resistance)
77
Campylobacter is a gram...
Negative rod
78
What is the #1 cause of food-borne illness in the US?
Campylobacter- sausages and hard meats, undercooked chicken
79
What illness often has a prodrome of fever, headache, myalgia, and malaise?
Campylobacter
80
What are the sxs of campylobacter?
Prodrome- fever, headache, myalgia, and malaise
Diarrhea
Fever
Symptoms are often low grade
81
What is the treatment for campylobacter?
Ciprofloxacin 1st
| Azithromycin 2nd
82
What are some complications from a campylobacter infection ?
Bacteremia in <1%
Guillian Barre
Reactive arthritis
83
What is the main cause of HUS in the US?
E. coli 0157: H7
84
What is an infection with E. coli 0157:H7 linked to?
Undercooked ground beef, drinking of unpasteurized juices and milk, working with cattle (1% of cattle in the US are carriers)
85
What are the symptoms of an infection with E. coli 0157:H7?
Bloody diarrhea
Severe cramping
Fever 0-30% of the time
Nausea vomiting common
86
What are you going to see in hemolytic uremic syndrome?
Acute renal insufficiency
Hemolytic anemia
Thrombocytopenia
87
What populations is HUS severe in?
Children and elderly
88
HUS can/cannot be fatal?
Can be fatal
89
What test differentiates TTP from HUS?
ADAMTS 13 test differentiates TTP from HUS
| + in TTP
90
What labs are you going to see in HUS?
```
Blood cultures are often negative
Anemia
Decreased haptoglobin and increased LDH
Negative Coombs (nothing coating RBCs)
Thrombocytopenia
Elevated creatinine
Hematuria, proteinuria
```
91
What is the treatment for HUS?
Supportive
| Antibiotic use is controversial
92
What is the mortality rate associated with HUS?
5-20% mortality
93
What agents are responsible for non inflammatory diarrhea?
```
Staph toxin
Bacillus cereus
Listeria monocytogenes
Enterotoxigenic e Coli
Vibrio cholera
Norovirus
Protozoal infections such as giardia, amoeba
```
94
Staph food poisoning is actually from the ____ not the bacteria
Toxin
95
Staph food poisoning is more common in foods with....
High salt or sugar content (cream sauces, custard, hams, canned meat)
96
Staph food poisoning onset is fast/ slow
Fast onset- 4-8 hours
97
What are the symptoms of staph food poisoning?
Cramping, diarrhea, nausea, vomiting
98
What is the treatment for staph food poisoning?
Usually self limited- antibiotics are not recommended, resolves quickly
99
Listeria monocytogenes is/ is not foodborne
Is typically food borne
100
What populations are more susceptible to a listeria monocytogenes infection?
Pregnancy
| Immunosuppressed
101
What can happen when a pregnant woman becomes infected with listeria monocytogenes?
Spontaneous abortion, sepsis
102
What can result from a listeria monocytogenes infection?
Bacteremia and meningitis
103
Listeria is a gram...
Positive rod/ bacillus
104
What is a predisposing risk factor to a listeria infection?
Previous corticosteroid infection
105
In pregnancy related infections with listeria, ___% of cases end in fetal death
Listeria
106
Symptoms of listeria...
```
Fever
Chills
Muscle aches
Nausea
Diarrhea
```
107
What is treatment of choice in a listeria infection and why?
Ampicillin because it can cross the blood brain barrier to treat meningitis
108
How does Enterotoxigenic E. coli compare to E. coli 0157:h7?
Not the same infection
| Usually less severe when compared to 0157 infection
109
What organism is the main cause of traveler's diarrhea?
Enterotoxigenic E. coli
110
Enterotoxigenic E. coli can be...
A shiga toxin producer but not usually
111
What are the symptoms of an infection with Enterotoxigenic E. coli?
Profuse diarrhea, usually not bloody
Fever
Abdominal cramping
112
How is Enterotoxigenic E. coli diagnosed?
By stool culture or PCR
113
What are the treatment options for Enterotoxigenic E. coli?
Cipro 500 mg po bid X 7 days or
Trimeth/sulfa 180/800 mg po bid x 7 days or
Azithromycin 250mg 2 po on day 1 then 1 po day 2-5
114
Vibrio cholera is a ____borne illness
Waterborne
115
The usual cause of vibrio cholera is...
Poor water sanitation
116
What food carrier vibrio cholera?
Contaminated shellfish - raw oysters
117
What enterotoxin results in a massive secretion from the small bowel?
Vibrio cholera
118
What is the incubation time of vibrio cholera?
12-72 hours after ingestion
119
What are the symptoms of cholera?
Rapid dehydration- profuse watery diarrhea because you lose 1-3 liters per day up to 20 liters per day
120
What infection is associated with "rice water stools" ?
Cholera
121
Is fever common with cholera?
No, fever is rare
122
What is the mortality rate associated with cholera?
1-10%
123
What is the treatment for cholera?
Hydration!
| Doxycycline or cipro Can limit the duration of the disease but dehydration is the main issue
124
What is viral gastroenteritis?
Inflammation of the stomach and intestinal tract
125
How many cases of viral gastroenteritis are there each year?
211-375 million
126
What are the sxs of viral gastroenteritis?
```
Sudden onset, rapid resolution
Diarrhea
Nausea
Vomiting
Stomach cramping
```
127
What is the most common cause of non bacterial acute gastroenteritis?
Norovirus
128
Norovirus persists in the environment/ does not persist in the environment
Persists in the environment and is hard to eradicate
129
Where do outbreaks of Norovirus commonly occur?
Nursing homes, hospitals, schools, day cars, military bases, cruise ships, hotels
130
How is Norovirus transmitted?
Person to person contact, contaminated food and water, airborne
Small doses can lead to infection
Contagious even after symptoms resolve- may shed up to several weeks
131
What are the clinical findings of Norovirus?
```
Sudden onset of vomiting, diarrhea
Nausea
Fever
Abdominal cramping
1-3 days
```
132
What is the treatment for Norovirus?
Self limiting- supportive care
133
What is the prevention of Norovirus?
Hand washing at least 20 seconds with soap and water
Decontamination of surfaces with beach 10%
Infected food handlers must stay away from work for 48-72 hours after symptoms resolve
134
For all of these GI illnesses, what is the gold standard testing?
Stool testing, 48-72 hour turn around time
| PCR is now available for GI pathogens- good sensitivity for multiple pathogens but expensive
135
Fever is/ is not always present in diarrheal illnesses
Is not
136
What needs to be considered when treating with an anti diarrheal/ anti motility agents?
Is the cause inflammatory or non inflammatory
