infectious diarrhea

Question 1

1)What are the two leading causes of death worldwide?

Answer 1

Infections (24.4%), ischemic heart disease (12.5%), pneumonia (8.5%) and diarrhea (5.8%)

Question 2

2)What age group is preferentially affected by diarrhea

Answer 2

The young and old

Question 3

3)What is the leading cause of morbidity and death with diarrhea?

Answer 3

dehydration

Question 4

4)What is the most reversible cause of morbidity and death with diarrhea

Answer 4

dehydration- rehydration saves lives

Question 5

What causes infectious gastroenteritis in US?

Answer 5

Most cases it is unknown. Viral is second most common, bacterial/parasitic is least common

Question 6

5) What is the difference between inflammatory and non-inflammatorydiarrhea clinically and anatomically

Answer 6

non inflammatory diarrhea occurs from the upper small bowel and is watery. Inflammatory diarrhea occurs from the colon and has increased T cells, WBC, and RBC

Question 7

6) Name 3 organisms that cause inflammatory and 3 that cause non inflammatory diarrhea

Answer 7

Non inflammatory: Norwalk, Rotavirus,Giardia, Cholera, Enterotoxigenic E coli. Inflammatory: : C. jejuni, Shigella, Salmonella, E. coli O157:H7, C. difficile, E. histolytica

Question 8

Cholera mechanism

Answer 8

Produces toxin that binds to ganglioside GM1 receptor and affects cAMP levels.

Question 9

Cholera incubation period, symptoms

Answer 9

18hr to 5 days incubation period. Sx: abrupt diarrhea (rice water stool, up to 24 liters per day), vomiting

Question 10

Signs of dehydration

Answer 10

decreased pulse volume, low BP, poor skin turgor, sunken eyes, decreased urine, decreased MS, metabolic acidosis, hypoglycemia, hypokalemia

Question 11

What is an oral rehydration solution made of and how does it work?

Answer 11

Common juice / soft drink plus heaping teaspoon sucrose. Promotes reabsorption of Na and Cl

Question 12

What causes travelers diarrhea usually

Answer 12

enterotoxigenic E coli- this decreases over time due to immunity and behavior

Question 13

compare norwalk virus and rotavirus: epidemiology, age, transmission, incubation, duration

Answer 13

norwalk: family and community epidemics in winter, affects older children and adults, fecal-oral and contaminated shellfish and water transmission, 1-2d incubation, 1-2 day duration. Rotavirus: sporadic in winter occasional epidemic, affects infants and young children, fecal-oral transmission, 1-3 day incubation, 5-8 d duration

Question 14

Giardia symptoms

Answer 14

Diarrhea (100%), fatigue (97%), cramps (83%), vomiting (17%), fever (21%), bloating, gas, foul smelling diarrhea

Question 15

E. Coli 0157:H7 age, duration, symptoms

Answer 15

young children and elderly, lasts 2-4days, symptoms range from asymptomatic to non-bloody diarrhea, hemorrhagic colitis, hemolytic uremic syndrome and thrombotic thrombocytopenia purpura

Question 16

How does E. Coli 0157:H7 toxin work

Answer 16

Verotoxin Shiga-like toxin (SLT-I/II). Binds especially to human renal endothelial cells. Inhibits protein synthesis

Question 17

reservoirs for E. Coli 0157:H7

Answer 17

dairy and beef cattle intestines

Question 18

7) What is the leading cause of acute bacterial diarrhea in U.S., all ages?

Answer 18

Rotavirus

Question 19

8) What is the predominant cause of nosocomial diarrhea?

Answer 19

C. difficile

Question 20

C. Difficile symptoms

Answer 20

may be mild diarrhea, watery or bloody, or may have fever, leukocytosis with severe colitis

Question 21

What defines nosocomial

Answer 21

> 3 days in hospital

Question 22

Site and pathogens involved in enteric fever

Answer 22

site: nodes, blood, gallbladder. Pathogens: Salmonella typhi,S. paratyphi, ± Yersinia

Question 23

Salmonella enteric typhi causes what disease

Answer 23

typhoid fever

Question 24

Risks for typhoid fever

Answer 24

fecal contamination, food/water, contact with carrier