IDIS GI Intoxications and Infections Flashcards
What is the best indicator of an intestinal infection?
Long incubation period
Food intoxication has a ____ incubation time (___ to ____). Is there a fever? Are there fecal leukocytes? What are the etiologies?
Short (2-12 hrs)
No fever or fecal leukocytes
S. aureus, B. cereus, C. perfringens
Unique features of S. aureus food intoxication
Projectile vomiting, little or no diarrhea, no fever
1-4 hr incubation
Dairy products, salted foods, creme puffs, mayonnaise containing products
Type 1 food intoxication with B. cereus
Nausea, vomiting, little to no diarrhea
2-3 hrs incubation
Fried rice
Toxin heat stable
Type 2 food intoxication with B. cereus
Profuse diarrhea, little to no vomiting
10-12 hrs incubation
Cooking food kills vegetative cells
C. perfringens food intoxication
Abdominal cramps and diarrhea
8-24 hrs incubation
Diarrhea is less than 24 hours total
Cooking food kills cells, but the spores remain
What is the most common cause of food poisoning? Associated with fried rice? Associated with leaving food on the stove warming for too long?
C.perfringens
B.cereus
C.perfringens
S.aureus has ____ enterotoxins that are ____ _____. Causes nausea and vomiting. The enterotoxins cause ____ release which binds to vagaries afferent neurons causing ____.
8, heat stable
Serotonin release
Emesis
C.perfringens is a ____ _____ toxin leading to watery diarrhea. Toxin disrupts ____ _______ and the water follows.
Heat labile
Ion transport
B.cereus and C.perfringens are both gram positive rods. Which is aerobic and which is anaerobic?
B.cereus- aerobic
C.perfringens- anaerobic
Pt presents with emesis 2 hrs after eating hamburger, potato salad, and leftover fried rice. Aerobic culture of potato salad contained many gram positive cocci. What is the bacteria?
S.aureus
Most common cause of winter diarrhea in infants? Winter vomiting in children and adults?
Norovirus for both
Rotavirus is the second most common cause of winter diarrhea in children under 2 years of age, this is different now because of the vaccine
What do all the viral gastroenteritis agents have in common?
They are all naked because the GI tract has the ability to break down the envelope on other viruses
There is only one DNA virus that causes viral gastroenteritis- adenovirus
Symptoms for viral gastroenteritis
LOW-GRADE FEVER, abdominal pain, watery diarrhea, nausea and vomiting
Characteristics of a norovirus virus gastroenteritis
Sudden onset low-grade fever, N/V/D
Sx for 12-60 hrs
Most common in children less than 5 years of age
Organisms that cause bacterial gastroenteritis that is noninflammatory? Symptoms? Invasion of small intestine? Fecal leukocytes?
E.coli, V.parahaemolyticus, V.cholerae
Large volume diarrhea and abdominal cramps, vomiting is less common
No invasion of small intestine
No fecal leukocytes
What E.coli has abrupt onset, watery diarrhea, cramping and abdominal pain, and lasts about 24 hours?
ETEC (enterotoxigenic E.coli)
Has LT and ST toxins
What E.coli lasts for several days?
EAEC (enteroaggregative E.coli)
Adhere, mucus, cytotoxin (small and large intestine)
What two types of E.coli cause traveler’s diarrhea?
ETEC and EAEC
Enterotoxigenic E.coli and Enteropathogenic E.coli
What is given prophylactically for bacterial gastroenteritis?
Rifaximin
Characteristics of Vibrio parahaemolyticus?
Epidemiology?
Curved oxidase positive gram-neg rod, halophile (requires salt to grow)
24 hr incubation
Explosive diarrhea to cholera-like illness
HA, abd cramps, N/V, low grade fever
Epi- raw shellfish, most common cause of shellfish associated gastroenteritis
Treatment of V.parahaemolyticus
Oral replacement of fluids and electrolytes
Azithromycin
Proper cooking of shellfish
Characteristics of Vibrio cholerae?
Curved gram-neg rod
India, West Bengal, Bangladesh, South America, Louisiana
Shellfish and crabs
Abrupt onset of watery diarrhea, “rice water” stools, vomiting may occur
Treatment for V.cholerae?
Replace fluids and electrolytes
-1 liter water, 8 teaspoons sugar, 1 teaspoon salt
Tetracycline reduces severity and length of disease
Which symptom is more common in viral gastroenteritis than bacterial gastroenteritis?
A. Vomiting
B. Diarrhea
C. Abdominal pain
Vomiting is more common in viral compared to bacterial
What is the most common intestinal protozoan?
Giardia lamblia
Treatment for Giardiasis?
Metronidazole, nitazoxanide, quinacrine HCl
What has sporulated oocysts that are the infectious form of the parasite?
Cyclosporine cayetanensis
Treatment for cyclosporiasis?
Trimethoprim-sulfamethoxazole
What is characterized by a small number of oocysts causing diarrhea? (150 oocysts)
Cryptosporidium parvum
Treatment of cryptosporidium?
Nitazoxanide
Antidiarrheal drugs for temporary relief
