Bacterial Gastroenteritis Flashcards
What bacteria is characterized as being gram negative, helical shaped and is the leading cause of foodborne illness in North America?
Campylobacter jejuni
Which bacterial cause of gastroenteritis has the following symptoms: fever, abdominal pain and cramping, and blood streaked, inflammatory diarrhea?
Campylobacter jejuni
What is the route of transmission for Campylobacter jejuni?
ingestion of contaminated food and water and the fecal-oral route
What is the infection control protocol in the hospital for campylobacter jejuni?
routine practices and contact precautions
How long does it typically take for symptoms associated with campylobacter jejuni to resolve?
within 1 week
What bacteria is gram negative, bacillus-shaped and associated with 2 different conditions; one of which is not really seen in Canada?
salmonella enterica
Which condition of salmonella enterica is most common in Canada and what are the associated symptoms?
salmonellosis; fever, nause, loss of appetite, headache, myalgias, malaise, abdominal cramping and pain and inflammatory diarrhea (no blood); resolves within 1-2 weeks
What type of stool would you expect to see in a person with salmonellosis?
inflammatory diarrhea, typically with no blood
Does salmonelosis go into the bloodstream?
no
Which bacterial cause of gastroenteritis is; gram negative, bacillus-shaped bacteria, produces enterotoxin, referred to as “traveller’s diarrhea”, non-inflammatory diarrhea?
ETEC
What are common symptoms of ETEC and when do symptoms typically resolve?
bloating, fever, abdominal cramps, N&V, watery non-inflammatory diarrhea (4-5 loose stools per day), typically resolves in 1-3 days
What is the route of transmission for ETEC?
- ingestion of contaminated food and water
- person to person (fecal oral route)
What is the infectious dose for ETEC?
~100 organismss
Which bacteria produces a verocytotoxin that directly damages intestinal mucosa, causing lesions and bleeding, can bind to neutrophils?
VTEC verocytotoxigenic E. coli
What are the symptoms of VTEC?
- inflammatory diarrhea (10 or more bowel movements per day)
- abdominal cramping, pain or tenderness
- low grade fever
- hemorrhagic colitis in 6% of infected patients
How quickly can symptoms lead to hemorrhagic colitis in VTEC?
within 24 hours after symptom onset
What bacteria is transmitted in contaminated milk, fruit juice, ground beef, and produce like spinach and sprouts?
VTEC
What is the leading cause of acute kidney failure in children?
hemolytic uremic syndrome
What aggravates hemolytic uremic syndrome?
antimotility drugs and antibiotics
How does hemolytic uremic syndrome lead to kidney failure?
verocytotoxin invades the bloodstream and destroys RBCs, the damaged RBCs clog the microvasculature of the kidney, causing kidney failure
What are symptoms of hemolytic uremic syndrome?
- fever, abdominal pain
- pale skin tone, fatigue, irritability
- unexplained small bruises or bleeding from nose or mouth
- decreased urination
- edema
What is the treatment for hemolytic uremic syndrome?
RBC and platelet transfusions, plasma exchange, kidney dialysis
Which form of bacterial gastroenteritis is a complication associated with age extremes?
hemolytic uremic syndrome
Which form of bacterial gastroenteritis is gram negative, rod-shaped bacteria, that mainly affects children around the age of toilet training?
Shigella spp.
What are the symptoms associated with shigella spp. infections?
- inflammatory diarrhea (bloody with mucus)
- abdominal cramps
- rectal pain
- fever
- nausea
How long does it take for symptoms to resolve in shigella spp infections?
2-3 days, but carrier for ~ 4 weeks
What is the most common species of shigella in north america?
S. Sonnei
Which bacteria is gram positive, endospore-forming, that produce exotoxins, common symptoms include watery, foul smelling diarrhea, mild abdominal cramping and tenderness and can advance to pseudomembranous colitis?
C. diff
Which type of bacterial infection is most associated with hospitals and nursing homes?
c. diff
What does enterotoxin (toxin A) cause in c. diff?
diarrhea and inflammation
What does cytotoxin (toxin B) cause in c. diff?
induces cell damage and facilitates lesion formation
what bacteria do we need to suspect if patient develops diarrhea in association to antibiotics and why?
C. diff, exposure within 2 months because the normal flora that competes with the pathogen for nutrients is no longer there so they can come out of spore form, due to the destruction from antibiotics
What are the treatment options for C. diff?
- discontinuation of implicated antimicrobial agent and supportive therapy
- vancomycin to target C. diff if symptoms do not resolve
- if relapse, fecal transplant
What are the complications associated with C. diff?
- bowel perforation: due to damage to intestinal wall
2. toxic megacolon: gross distention of colon
What is the most common causative factor of gastroenteritis?
viral
What are the symptoms that are most commonly caused by viral gastroenteritis?
- non- inflammatory (secretory diarrhea)
- abdominal cramping
- nausea and vomiting
- fever, chills, clammy skin
- weight loss and lack of appetite
How quickly do symptoms of viral gastroenteritis resolve?
appear within 24 hours of infection and resolve within 12 to 60 hours after symptom onset
In addition to viral gastroenteritis being transmitted by contaminated food and water, as well as fecal oral route, how else can it be transmitted?
aerosols from vomit
Why is viral gastroenteritis self-limiting?
once epithelial layer is destroyed, replacement cells begin to grow and then function is restored.
What is the most common virus in children between 6 months and 2 years of age?
rotavirus
What is the incubation period of rotavirus?
2-3 days
What is the leading cause of viral gastroenteritis?
norovirus
What is the incubation period for norovirus?
12-48 hours
How is norovirus transmitted?
fecal-oral route, direct contact with oral secretions, contaminated fomites and aerosolized vomit
What is known as “food poisoning”?
intoxication
What are common causes of intoxication?
S. aureus and clostridium perfringens
What are the symptoms related to intoxication?
N&V, cramps, diarrhea and NO fever
What is the treatment for intoxication?
- fluid replacement
- antiemetic drugs
What is gram positive, cocci-shaped bacteria that produces an enterotoxin that causes food poisioning?
staphylococcus aureus
What phase of parasites are the infectious form?
the cyst
What is the trophozoite form of the parasite?
the replicating form
What animals are proprietors of spreading acute giardiasis?
beavers (water dwelling animals)
What are the symptoms of acute giardiasis?
severe, foul smelling, greasy, fatty diarrhea, gas, abdominal cramps, malaise, bloating, nausea and vomiting.
how can you kill the G. intestinalis cysts found in water?
fully boiling the water (10 minutes at a roiling boil)
What is the treatment of acute giardiasis?
tinidazole (antimicrobial)
