Deck 34: Gastrointestinal Infections and Food Poisoning

Question 1

What is the most common cause of travelers' diarrhea?

A)Giardia lamblia
B)Escherichia coli
C)Entamoeba histolytica
D)Clostridium difficile

Answer 1

B
Travelers' diarrhea is most commonly caused by enteropathogenic E.coli.This illness has a short incubation period (usually less than 24 hours) and normally lasts between 1 and 3 days.If a diarrheal illness lasts longer than this or develops in the days or weeks after a traveler returns home, the patient more likely has a different pathogen.

Question 2

What virus causes an acute self-limited diarrheal illness that is highly contagious through contaminated food, water, fomites, or person-to-person contact and is associated with vomiting and low-grade fever?

A)Astroviruses
B)Rotaviruses
C)Enteric arenaviruses
D)Norovirus

Answer 2

D
The noroviruses are named after the original strain (Norwalk virus), first isolated in patients from a town with that name in Ohio in 1968.These viruses cause an acute, self-limited diarrheal illness associated with vomiting and low-grade fever.The disease is highly contagious and is transmitted by the fecal-oral route, fecally contaminated food or water, environmental fomites, and by person-to-person contact.

Question 3

What is the environmental reservoir of Campylobacter?

A)Lakes and rivers
B)Fish
C)Arthropod vector
D)Wild and domestic animals

Answer 3

D
The environmental reservoir of Campylobacter includes both wild and domestic animals, most frequently birds.This is usually a foodborne infection, often with poultry as the source.

Question 4

Why is the travel history of the patient important when evaluating a person with acute diarrhea?

A)Travel to different countries puts one at risk for various infections.
B)Some countries are dirtier than others.
C)The United States is clean, and usually bad infections cannot be contracted here.
D)All of the above.

Question 5

What type of diarrheal illness has a rapid onset of symptoms after food ingestion (usually less than 12 hours)?

A)Diarrhea where the mucosal surface is invaded
B)Diarrhea where the full bowel thickness is invaded
C)Diarrhea caused by endotoxins
D)Diarrhea caused by enterotoxins

Question 6

Which of the following is an opportunistic virus that can lead to diarrhea in an immunocompromised host?

A)Rubella
B)Parvo B19
C)Cytomegalovirus
D)Filovirus

Question 7

All of the following organisms can cause enterotoxin-mediated diarrhea except:

A)Salmonella typhi.
B)Clostridium perfringens.
C)Vibrio cholerae.
D)Staphylococcus aureus.

Question 8

All the following organisms invade the bowel mucosal surface to produce diarrhea except:

A)Salmonella spp.
B)Vibrio cholerae.
C)Campylobacter spp.
D)Shigella spp.

Question 9

What defense mechanism does the colon have to guard against infection?

A)IgA antibody is produced.
B)IgE antibody is produced.
C)Nonspecific immune defenses are resident here and take care of pathogens.
D)The anatomic structure makes it tough for organisms to adhere.

Question 10

How is diarrhea disease usually contracted?

A)By air
B)By blood
C)By contaminated food or water
D)By respiratory droplet

Question 11

What type of diarrheal illness produces fever, leukocytosis in peripheral blood, and fecal leukocytes?

A)Diarrhea in which the mucosal surface is invaded
B)Diarrhea in which the full bowel thickness is invaded
C)Diarrhea caused by endotoxins
D)Diarrhea caused by enterotoxins

Question 12

What common organism invades the full thickness of the bowel with lymphatic spread?

A)Vibrio cholerae
B)Campylobacter jejuni
C)Salmonella typhi
D)Aeromonas spp.

Question 13

All of these patient history questions will help focus the search for the pathogen except:

A)Does the patient have a history of previous gastrointestinal symptoms?
B)Did the patient eat any hot food?
C)Does the patient have an underlying illness?
D)Is the patient taking any medication?

Question 14

What is the most common cause of bacterial gastroenteritis in the world?

A)Salmonella typhi
B)Campylobacter jejuni
C)Shigella sonnei
D)Yersinia enterocolitica

Question 15

What is the most common cause of death among patients with diarrhea?

A)Sepsis
B)Septic shock
C)Dehydration
D)Secondary bacterial infections

Question 16

How does the small intestine try to prevent infection?

A)Caustic secretions
B)Acidic secretions
C)Anatomic structure
D)Peristalsis

Question 17

Disease caused by which of the following organisms has fever, abdominal cramping, diarrhea, and stools with gross blood and pus?

A)Staphylococcus aureus
B)Clostridium difficile
C)Campylobacter jejuni
D)Bacillus cereus

Question 18

What virus is the leading cause of diarrhea in children younger than age 5?

A)Enteric adenoviruses
B)Astroviruses
C)Rotavirus
D)Calicivirus

Question 19

What type of diarrheal illness has no fever and no blood or pus in the stool?

A)Diarrhea where the mucosal surface is invaded
B)Diarrhea where the full bowel thickness is invaded
C)Diarrhea caused by endotoxins
D)Diarrhea caused by enterotoxins

Question 20

What diarrheal illness occurs when organisms invade through the bowel wall, cause bacteremia, and also cause a mesenteric lymphadenitis that may be confused with appendicitis?

A)Diarrhea in which the mucosal surface is invaded
B)Diarrhea in which the full bowel thickness is invaded
C)Diarrhea caused by endotoxins
D)Diarrhea caused by enterotoxins

Question 21

What types of stools are characteristic of someone who has cholera?

A)Black-blood stools
B)Coffee-ground stools
C)Black tar stools
D)Rice-water stools

Question 22

What organism grows best at 42° C and in a reduced oxygen atmosphere (5% to 10%)?

A)Shigella sonnei
B)Clostridium difficile
C)Campylobacter jejuni
D)Escherichia coli

Question 23

What is the most important cause of iatrogenic diarrhea in adults?

A)Yersinia enterocolitica
B)Cryptosporidium jejunum
C)Vibrio vulnificus
D)Clostridium difficile

Question 24

A man and his family drive to the coast and have an oyster dinner.A couple of days later, the man arrives at the emergency department with a fever, bullous skin lesions, and diarrhea.He is extremely ill and the physician questions whether he is septic.Blood and stool specimens are collected.The microbiologist notices curved gram-negative rods on the stool Gram stain.What is the most probable organism causing this condition?

A)Yersinia enterocolitica
B)Cryptosporidium jejuni
C)Vibrio vulnificus
D)Vibrio cholerae

Question 25

All of the following organisms are commonly implicated in a foodborne outbreak except:

A)Staphylococcus aureus.
B)Salmonella spp.
C)Clostridium botulinum.
D)Vibrio cholerae.

Question 26

What intestinal parasite is able to leave the intestines and cause metastatic diseases, especially liver abscesses?

A)Giardia lamblia
B)Entamoeba histolytica
C)Cryptosporidium parvum
D)Microsporidia

Question 27

What diarrheal pathogen can produce a disease that may lead to hemolytic-uremic syndrome (hemolytic anemia, low platelet count, and kidney failure)?

A)Enterohemorrhagic Escherichia coli (EHEC)
B)Enteroinvasive E.coli (EIEC)
C)Enteropathogenic E.coli (EPEC)
D)Enterotoxigenic E.coli (ETEC)

Question 28

What toxin does Shigella spp.produce?

A)Typhi
B)Enterotoxin
C)Shiga
D)Campy

Question 29

What condition caused by acute diarrheal disease can significantly contribute to the morbidity and mortality of the disease?

A)Metabolic alkalosis
B)Metabolic acidosis
C)Volume depletion
D)Starvation

Question 30

What organ is colonized in a patient that carries Salmonella typhi?

A)Colon
B)Gallbladder
C)Rectum
D)Small intestine

Question 31

What is the most commonly identified intestinal parasite in the United States?

A)Giardia lamblia
B)Entamoeba histolytica
C)Cryptosporidium parvum
D)Microsporidia

Question 32

A microbiologist is reading a Gram stain and observes gram-negative, curved rods with a seagull-wing appearance.What organism could this be?

A)Campylobacter or Vibrio
B)Shigella or Vibrio
C)Campylobacter or Shigella
D)All of the above

Question 33

What organism that causes gastroenteritis can be found in aquaculture-farmed fish?

A)Salmonella
B)Campylobacter
C)Vibrio
D)Shigella