Exam 1: Gastrointestinal Infections (OBrien) Flashcards
What type of pathogens can cause GI infections? Majority are caused by?
- viral (majority caused by)
- bacterial
- parasitic
What is the biggest symptoms of GI infections that is responsible for MORBIDITY and MORTALITY?
vomiting and diarrhea–> leads to dehydration
ACUTE diarrhea:
- ______ in CONSISTENCY of bowel movements (loose/uniformed stool)
- _______ in frequency of stools to _____ per day
decrease in consistency
increase in frequency; greater than or equal to 3
PERSISTENT diarrhea:
*diarrhea lasting between _______ days
14-30 days
What is inflammation f the lining of the GI tract?
infectious diarrhea= gastroenteritis
T/F Most of those who die of diarrheal illness in the U.S. are elderly
TRUE
Groups at risk for GI infections (4)
- Travelers and campers
- Patients in chronic care facilities
- Military personnel overseas
- Immunocompromised patients
T/F The etiologic agent of GI infections is RARELY IDENTIFIED
TRUE
- Infrequency of stool samples collected
- Inability of many laboratories to detect full range of pathogens [especially viruses]
Etiology of SECRETORY Diarrhea (4)
- virus (norovirus OR rotavirus)
- ETEC (enterotoxigenic E.coli)
- Vibrio cholerae
Etiology of INFLAMMATORY Diarrhea (5)
- shigella
- salmonella
- C.diff
- Campylobacter
- EHEC (enterohemorrhagic E.coli)
______ virus is more common in CHILDREN vs _____ virus being more common in ADULTS
rotavirus; notovirus
What is the most common cause of traveler’s diarrhea?
ETEC
How are BACTERIAL GI infections mostly transmitted?
contaminated food or water
SECRETORY VS. INFLAMMATORY
Organisms cause altered movement of ions and water
secretory
SECRETORY VS. INFLAMMATORY
Severe watery diarrhea
secretory
SECRETORY VS. INFLAMMATORY
toxin production; INCREASE in Cl secretion; DECREASE Na absorption
(increase colonic secretion)
secretory
SECRETORY VS. INFLAMMATORY
Organism adhere to intestinal mucosa
inflammatory
SECRETORY VS. INFLAMMATORY
Ulceration of; death to intestinal epithelium —>DYSENTERY diarrhea
inflammatory
________= passing grossly blood stools
dysentery
not all stools may contain visible blood
SECRETORY VS. INFLAMMATORY
watery INCREASED volume (+) less stools NO blood few PMN
secretory
SECRETORY VS. INFLAMMATORY
blood INCREASED volume more stools (greater than 10) BLOOD many PMN
inflammatory
What are complications of secretory diarrhea? (3)
- severe dehydration
- shock
- electrolyte imbalance
What are complications of inflammatory diarrhea ?
- mild dehydration
- seizures
- sepsis
- toxic megacolon
When is it recommended to obtain stool cx? (3)
- dysenteric diarrhea
- diarrhea lasting longer than 7 days
- diarrhea where outbreak is suspected
When is it NOT recommended to obtain stool cx? (3)
mild to moderate watery diarrhea
What are routinely checked in stool cx? (3)
- campylobacter
- salmonella
- shigella
T/F Correcting fluid and electrolyte imbalances to prevent dehydration is the CORNERSTONE of management
TRUE
What is used to assess the degree of dehydration?
percentage of body weight LOST
BP, HR, breathing, skin fold, etc
What are the types of rehydration therapy?
oral rehydration
-IV fluid therapy
What is recommended for mild to moderate dehydration?
oral rehydration therapy (ORT)
What are the necessary components of ORT? (5)
- Carbs
- Na
- K
- Cl
- water
What can help prevent over hydration?
oral rehydration therapy
advantages of ORT (2)
- inexpensive and non-invasive
- does not require hospitalization
What is recommended for severe dehydration?
IV fluid therapy
T/F Lactated ringer’s solution is preferred for IV fluid therapy over normal saline
TRUE
When is ANTIMICROBIAL therapy NOT recommended? (2)
- mild to moderate diarrhea (b/c most are viral)
- EHEC diarrhea
When is ANTIMICROBIAL therapy recommended? (2)
- febrile dysenteric diarrhea (Shigella, Campylobacter, Salmonella)
- traveler’s diarrhea (ETEC)
SEVERITY of diarrhea
mild
3 or less stools per day
SEVERITY of diarrhea
moderate
4 or more stools per day
SEVERITY of diarrhea
severe
6 or more stools per day
fever
presence of blood
When deciding antimicrobial therapy, what should be taken into consideration?
local susceptibility patterns
antimicrobial therapy
ETEC- watery diarrhea
Capri x 1-3 days
antimicrobial therapy
ETEC- watery diarrhea
alternative
Zpak OR
Rifaximin
(x3days)
antimicrobial therapy
shigella
Cipro x 1-3 days
antimicrobial therapy
salmonella
Cipro OR Levo x 7-10 days
antimicrobial therapy
campylobacter
Zpak x 3 days
Due to increased rates of resistance ____ cant be used for Campylobacter
FQs
use Zpak
Salmonella is very resistant; what can be used inpatient?
ceftriaxone
Antibiotic therapy is NOT recommend for _____ due to potential for worsened outcomes. They increase the risk of HEMOLYTIC UREMIC SYNDROME (HUS)
EHEC
inflammatory diarrhea
observed in children and elderly
HUS: acute renal failure; thrombocytopenia; hemolytic anemia
Anti motility agents ARE NOT recommended in patients with_____? Why?
dysenteric diarrhea
- slows fecal transit time and extend toxin associated damage
- puts pt at risk of HUS
What 2 ANTI-MOTILITY agents are used for WATERY diarrhea? Which is used more often?
- Loperamide (more commonly used)
- Bismuth subsalicylate (pepto bismol)
When should Pepto Bismol NOT be used? (3)
- in children
- allergy to salicylate
- anticoagulant pts
T/F There is a vaccine for ROTAVIRUS
TRUE
infants beginning at age 2 months
Campylobacter is more common in ____ countries and causes traveler’s diarrhea
Asian
When do the onset of traveler’s diarrhea usually occur?
during the first week of travel
Although prophylaxis is NOT indicated for traveler’s diarrhea, what can be used?
Cipro (has collateral damage though)
- Pepto Bismol
- Rifaximin for ETEC
T/F For traveler’s diarrhea usually self treatment
-take the medication when you first have symptoms
TRUE
or single dose of FQ (Cipro x1 day)
C.diff is a gram __________ bacteria
positive spore-forming ANAEROBIC
What is C.diff resistant to?
- heat
- drying
- pressure
- many disinfectants
(due to spores)
What are CLASSIC RISK factors for C.diff? (3)
- exposure to antibx
- prolonged stay in healthcare facility
- elderly
additional: PPI use, GI surgery, immunosuppression; inflammatory bowel disease
High Risk Antibx for C.diff
CCCF
- clindamycin
- 3rd and 4th gen cephalosporins
- Carbapenems
- FQ
T/F Toxin production is essential for C.diff manifestation
TRUE
only see C. diff infection in pts that produce the toxin
antibx disrupt the normal flora allowing C.diff to colonize
What is the primary mode of transmission of C.diff?
person to person spread through the fecal-oral route
________ w/ _______ = you should think C.diff
diarrhea w/ antibx OR healthcare exposure
Testing options for C.diff (3)
Patients with unexplained and new-onset diarrhea
- PCR
- GDH plus toxin
- PCR plus toxin
PCR
- most commonly used in hospitals
- highly SENSITIVE, so risk for false positive
- ONLY test if unexplained new onset diarrhea
What is used to determine the SEVERITY OF CDIFF? (4)
- fever (greater than 38.5)
- WBC (greater than 15,000)
- SCr (greater than 1.5)
- Albumin (less than 3)
Clinical Def of C.diff:
WBC less than 15,000 OR SCr less than 1.5
initial episode, NON-SEVERE
Clinical Def of C.diff:
WBC greater than 15,000 AND Scr greater than 1.5
initial episode, SEVERE
T/F Metronidazole associated with higher treatment failure rates when used for severe or complicated CDI
TRUE
risk factors:
- age ((greater than 60)
- hypoalbuminemia
- ICU stay
SE of Flagyl? (4)
- disulfam-like rx w/ alcohol (N and V/ face flushing)
- GI intolerance
- metallic taste
- peripheral neuropathy
_____ should be avoided in pts with macrolide allergy
fidaxomicin
_______ in comparison to Vanco caused fewer recurrences at 25 days after therapy for CDI
fidaxomicin
its the same as vanco w/ first occurence
T/F There are high cure rates w/o relapse for C.diff patients treated w/ FMT
TRUE
Zinplava (Bezlotoxumab)
- monoclonal antibody bind to C.diff toxin B
- NOT used to treat, but given w/ antibx
- INCREASED rate of cardiac failure
