Infections of GI tract: Infectious Diarrhea-Schoenwald- Exam 3 Flashcards
Infectious Diarrhea:
- onset?
- MC outbreaks?
- What hx do you need from the Pt?
- Acute in onset and lasting <2 weeks
- Community outbreaks (nursing homes, schools, cruise ships) suggest viral etiology or common food source
- Get travel history
Noninflammatory Diarrhea= watery, ________ diarrhea
nonbloody
Noninflammatory diarrhea:
- associated Sx?
- disrupts?
- Associated with cramping, bloating, nausea, vomiting
- Disrupts normal absorption in small bowel
T/F: In Noninflammatory diarrhea Tissue invasion does not occur.
-NO _____ _______ on smear
True! Tissue invasion does not occur-no fecal leukocytes on smear
Inflammatory Diarrhea= fever and _____ diarrhea
bloody
Inflammatory Diarrhea:
-causes ______ tissue damage
colonic
invasion of bacteria or toxin
Inflammatory diarrhea:
involves primarily the _____ colon
lower colon–>left lower quadrant cramping, urgency
Inflammatory Diarrhea:
-fecal ________ present because of invasion of mucosa
fecal leukocytes
DDx for inflammatory diarrhea
ulcerative colitis
Inflammatory diarrhea:
-Diarrhea >14 days most likely NOT due to _______ agent
infectious agent (except C diff)
Why do we classify as inflammatory or noninflammatory diarrhea?
- Major difference is colonic tissue invasion by the organism and/or toxin
- Helps to differentiate when it is “okay” to use promotility agents-Imodium
DO NOT use ______ agents in inflammatory diarrhea
promotility
Typical Stool Pathogens
- Salmonella
- Shigella
- Campylobacter
- Vibrio
- E coli O157:H7
- Clostridium diff: pseudomembranous colitis
- Norovirus
- Enterovirus
- Parasites-Giardia, Amoeba, Cyptosporidium
Causes of Acute Infectious Diarrhea: Noninflammatory (list examples)
- Enterotoxin production
- Norovirus
- Rotavirus
- Giardia
- Cryptosporidium
- Listeria monocytogenes
Acute infectious diarrhea:
-list the pathogens that are specifically associated with enterotoxin production (4 of them)
Staph aureus
Bacillus cereus
Enterotoxigenic E coli
Vibrio cholerae
Causes of Acute Infectious Diarrhea: inflammatory (list examples)
- Cytotoxin production
- Mucosal invasion
- Cytomegalovirus
- Entamoeba histolytica
Acute Infectious Diarrhea: inflammatory
-list the specific organisms associated with Cytotoxin production
- Enterohemorrhagic E coli 0157:H7
- Clostridium difficile
Acute Infectious Diarrhea: inflammatory
-list the specific organisms associated with Mucosal invasion
- Campylobacter
- Shigella
- Salmonella
“think-> invasion “make camp” (=campylobacter and make salmon (salmonaella)
Inflammatory Diarrheas:
-(list 5)
- Clostridioides difficile (new name)–>Previously Clostridium difficile
- Salmonella
- Shigella
- Campylobacter
- Escherichia coli 0157:H7
Clostridioides difficile (Clostridium difficile):
- main Sx is _____
- major risk factors?
- diarrhea
- Previous antibiotic usage(historically **clindamycin, penicillins and cephalosporins)
- Advanced age
- Previous hospitalization
- Nursing home resident
C difficile– the new definition:
- Presence of which Sx?
- incidence has _____ from 2000-2005
- CDI-C diff infection
- Presence of Sx in the form of 3 or more unformed stool over 24 hours for 2 consecutive days in conjunction with positive stools for pseudomembranes
- Prior antimicrobial use not included in new guidelines
- Incidence had tripled from 2000-2005
C difficile:
- clinical findings?
- _____ diarrhea
- ____ bowel movements per day
- fever present?
- Can lead to _____ _____ and colectomy
- **Watery diarrhea
- 15-30 bowel movements/day
- Abdominal pain or cramps
- Fever-low grade
- *Can lead to toxic megacolon and colectomy
C diff-lab findings
- Leukocytosis-often with bandemia (**left shift)
- Hypoalbuminemia
- *Positive stool C diff test
Lab Tests for C diff:
-list 3
- Molecular test-PCR
- –Highly sensitive and specific
- –Can be positive in asymptomatic patients
- Antigen detection–> nonspecific
- Toxin testing: Toxin A and B testing –high rate of false negatives
(do toxin testing first, if that’s negative, follow-up w/ PCR)
Initial Episode of C diff: mild/moderate
-leukocytosis?
-Creatine ?
Tx?
Leukocytosis <15000,Creat <1.5
tx: Vancomycin 125 mg po qid x 10 days OR Fidaxamin 200 mg po bid x 10 days
note: fidaxamin is expensive!!
Initial Episode of C diff: Severe
-leukocytosis?
-Creat.?
Tx?
Leukocytosis >15000, Creat >1.5 prior to CDI
tx:Vancomycin 125 mg po qid x 10 days OR fidaxamin 200 mg po bid x 10 days
Initial Episode of C diff: complicated
-sx?
Tx?
Hypotension or shock,perforation, megacolon
tx: Vancomycin 500 mg po qid or via NG tube and/or metronidazole 500-750 mg IV q 8 hrs
C diff: 1st recurrence
tx?
Vancomycin oral taper or Fidaxamin
C diff: 2nd recurrence
tx?
Vancomycin oral taper or Fidaxamin
-Fecal microbiota transplant
C diff prevention (2 main things):
- antibiotic _______
- Environmental _____ and hand hygiene
- Spores can live up to __ months on a surface
- Antibiotic stewardship
- Environmental control and hand hygiene
- -Spores can live up to 5 months on a surface
- -Health care worker important vector
- -Alcohol hand preps ineffective
- -For surfaces, chlorine based disinfectants effective
Salmonella”
- a gram _____ rod
- carried in the ___
- gram negative rod, Salmonella enteriditis
- Carried in GI tract of reptiles, bird
Salmonella:
- ____ million cases per yr in US
- most cases occur from?
- 3.7 million cases
- Most cases occur from eating contaminated meat or eggs or from infected food handlers
- Also associated with handling reptiles
Salmonella:
- Pts can remain culture positive for __ month(s) after treatment
- incubation period=
- 1 month after treatment–> can be long term carrier
- -Incubation 6-48 hrs
Salmonella:
- clinical sx?
- T/F: bloody stools are common
- Fever and diarrhea MC Sx
- Usually self limited
- Bloody stools uncommon
Salmonella:
______ up to 4% of time in previously healthy with gastroenteritis
-Metastatic spread to _____
- bacteremia
- Metastatic spread to vascular grafts, joints, kidneys and liver common in bacteremic patients
Salmonella: tx
- Most cases self limiting- if uncomplicated, no Abx
- **Ciprofloxacin= of choice,
- Bactrim (Trimeth/Sulfa) alternate
Typhoid fever:
- ______ typhi
- High risk areas?
- Salmonella typhi
- High risk areas- India, Pakistan, Caribbean, Mexico
T/F: typhoid fever is endemic to the US
NOT endemic to US-travel history vital for dx
Typhoid fever: transmitted by?
- contaminated food, sewage, and infected food handlers
- may be asymptomatic
Typhoid fever:
- Sx
- what is the key Sx (hint: skin rash)
Diarrhea Constipation Skin rash on torso and back-rose colored Fever Abdominal pain Weakness (Note: ppl can die from typhoid fever)
Typhoid fever:
- dx?
- tx?
- mainly clinical suspicion & use travel hx
- tx: Resistance to Abx is an issue
- Historic treatment is Fluoroquinolone-Cipro
- Ceftriaxone resistance is developing
- Due to resistance issues, current recommended tx is **Azithromycin for mild cases, **Carbapenems for more severe especially in cases with history of travel to SE Asia
Typhoid Fever:
-prognosis?
=Serious infection
- Can be fatal
- -Especially if ineffective treatment due to antimicrobial resistance issues.
Shigella is a gram _____ rod
negative
-“dysentery”
Shigella:
- ______ carriers
- how is the infections spread?
-Asymptomatic carriers
-Virulent: 10-100 organisms can cause infection; person to person spread
-Worldwide distribution 650,000 deaths per year in world
-Fecal oral spread, also flies and inanimate objects
(Linked to day care centers!!! Changing diapers and poor hand washing or a kid is a carrier of shigella it can spread )
Shigella:
-incubation period=
12 hours to 4 days
Shigella: Sx
- Diarrhea (bloody, watery, pus and mucus)-secretory
- Fever
- Stomach cramps
- Nausea
- Vomiting
- dehydration
Shigella: ddx
-Other bacterial infections-Vibrio
Viral
Parasites
Shigella: tx
- Rehydration
- Ciprofloxacin= 1st line tx
- Bactrim or Azithromycin alternate–> Recent strains show high rate of resistance
Campylobacter:
- a gram ______ rod
- associated with which foods?
negative
-Sausages and hard meats, undercooked chicken
Campylobacter:
- Prodrome Sx?
- other sx?
- Often have prodrome-fever, headache, myalgia and malaise
- Abdominal pain
- Diarrhea
- Fever
- Symptoms often low grade
Campylobacter: tx?
- Ciprofloxacin drug of choice
- Azithromycin alternate
Campylobacter: complications?
- Bacteremia in <1%
- Guillain Barre’ association (ascending paralysis)
- Reactive arthritis
Pathogenic E coli infections:
-Enterotoxigenic:
Shiga toxin + or - non 0157 strains ~80% of traveler’s diarrhea
Pathogenic E coli infections
Enterohemmorhagic:
Enterohemmorhagic-shiga toxin 0157 strains:
-E coli 0157:H7–> associated with Hemolytic uremic syndrome (HUS)
E coli 0157:H7-
- is the main cause of ______
- linked to _____?
- Sx?
- HUS in US
- Linked to undercooked ground beef, drinking of unpasteurized juices and milk, working with cattle (1% of cattle in US carry)
- Sx-bloody diarrhea, severe cramping, fever 0-30% of time, nausea/vomiting
Hemolytic Uremic Syndrome”
-is characterized by acute renal sufficiency, hemolytic anemia, and _________
thrombocytopenia
HUS:
-severe in which demographic?
Severe in children and elderly
Can be fatal
HUS:
-________ test differentiates TTP from HUS
ADAMS 13 test
–if +, you know it’s TTP
HUS: labs
Culture often negative Anemia Decreased haptoglobin and increased LDH Negative coomb’s Thrombocytopenia Elevated creatinine Hematuria, proteinuria
HUS: tx
- Supportive
- Antibiotic use controversial
- 5-20% mortality
Non inflammatory Diarrheas:
-list ex’s
Staph Toxin Bacillus Cereus Listeria monocytogenes Enterotoxigenic E coli Vibrio cholera Norovirus Protozoal infections-giardia, amoeba
Staph food poisoning:
-is from _____ NOT bacteria
toxin
Staph food poisoning is more common in foos with high _____ or sugar
salt! (cream sauces, custard, hams, canned meat)
Staph food poisoning:
- onset?
- Sx?
-Rapid onset 4-8 hrs
Sx: Cramping, diarrhea, nausea and vomiting
-Usually self limiting-abx not indicated
Listeria monocytogenes:
is typically ________
-which demographic is more susceptible to infection?
- foodborne
- Pregnancy (spontaneous abortion and sepsis) and immunosuppressed more susceptible to infection
- -Bacteremia and meningitis
Listeria is a gram _____ bacillus
positive
Listeria:
- previous ________ use is predisposing risk factor
- of pregnancy related cases, ___% end in fetal death
- corticosteroid use
- 22% end in fetal death
Listeria:
- Sx?
- tx?
- Symptoms can include fever, muscle aches, headache, stiff neck, confusion
- Tx: Ampicillin is treatment of choice–>Crosses blood brain barrier to treat meningitis
Enterotoxigenic E coli is NOT _____
O157:H7
Enterotoxigenic E coli is usually less severe when compared to ______ infection
0157
Enterotoxigenic E coli:
- is the main cause of _____
- _____ toxin producers
- traveler’s diarrhea
- Can be shiga toxin producers
Enterotoxigenic E coli:
sx?
dx?
Sx: Profuse diarrhea, fever, usually not bloody, abdominal cramping
-Diagnose by stool culture or PCR
Enterotoxigenic E coli:
-tx options?
- Cipro 500 mg po bid x 7 days- 1st line
- Trimeth/sulfa 180/800 mg po bid x 7 days
- Azithromycin 250 mg 2 po on day 1 then 1 po day 2-5
(Maybe they cant tolerate fluoroquinolones— 2nd line = trimeth/sulfa or azithromycin )
Vibrio cholera:
- organism?
- etiology?
- incubation period?
- Cholera
- *Waterborne–>Poor water sanitation or *Shellfish
- 12-72 hrs after ingestion
Vibrio Cholera is an enterotoxin resulting in ______
massive secretion from small bowel
Vibrio Cholera:
- Sx? (characteristic Sx?**)
- mortality %?
Sx:
- Rapid dehydration-profuse watery diarrhea-lose 1-3 liters per day up to 20 liters per day
- **“rice water stools”
- Fever is rare
-1-10% mortality
(notes:Can lose up to 20 L per day— can DIE from dehydration very quickly
“rice water stool”= THINK cholera)
Vibrio Cholera:
-tx?
-HYDRATION,HYDRATION,HYDRATION
-Doxycycline or Ciprofloxacin:
Can limit duration of disease but dehydration is the main issue
Viral Gastroenteritis= inflammation of the _____
-_____ million cases per year
- stomach and intestinal tract
- 211-375 million cases each year
Viral Gastroenteritis:
- onset?
- Sx?
- Sudden onset and rapid resolution
- Sx: Manifests clinically with diarrhea, nausea, vomiting, and stomach cramping
Enterotoxigenic E coli is usually less severe when compared to ______ infection
0157
Enterotoxigenic E coli is NOT _____
O157:H7
Norovirus is the MC cause for ______
nonbacterial acute gastroenteritis
Norovirus:
- persist in what environment?
- Outbreaks commonly occur in?
-Persist in environment and are hard to eradicate
- Sporadic or epidemic
- –Outbreaks commonly occur in nursing homes, hospitals, schools, day care, military bases, cruise ships and hotels
Norovirus:
-transmission:
- Transmission-person to person contact, contaminated food and water, airborne
- small dose leads to infection
Norovirus:
-how long are Pts contagious?
-Contagious even after symptoms resolve, may shed up to several weeks
Norovirus:
clinical Sx?
tx?
- Sudden onset vomiting or diarrhea
- Nausea
- Fever
- Abdominal cramping
- 1-3 days
- Self limiting
-Supportive treatment
Norovirus:
prevention?
- Hand washing for at least 20 seconds with soap and water
- Decontamination of surfaces with bleach 10%
- Infected food handlers away from work for 48-72 hours after symptoms resolve
Diarrheal illnesses: PEARLS
-Fever IS NOT always present in diarrheal illnesses
-Caution when using anti diarrheal meds and antimotility agents–Consider inflammatory vs non-inflammatory criteria
(Do not want to use antidiarrheals in Inflammatory diarrheas cuz you will likely worsen their sx and worsen the infection. But you can use these agents in non inflammatory diarrheas)
Diarrheal illnesses: PEARLS
- Fever not always present in diarrheal illnesses
- Caution when using anti diarrheal meds and antimotility agents–Consider inflammatory vs non-inflammatory criteria
