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Flashcards in Infectious diarrhea Deck (28)
1

What are the two leading causes of death worldwide?

Pnuemonia
Diarrhea

2

What causes morbidity and death in diarrhea?

Dehydration

Therefore, rehydration is mainstay of treatment

3

Two types of diarrhea

Non-inflammatory (watery)
small bowel

Inflammatory (High T, WBC, RBC)
colon

4

Definition of diarrhea

3 or more loose stools lasting more than 24 hrs

5

Location and infectious organisms in non-inflammatory and inflammatory diarrhea)

Non-inflammatory:
Site: Upper small bowel
Pathogens: Norwalk, Rotavirus, Giardia, Cholera, ETEC

Inflammatory:
Site: Colon
Pathogens: C. jejuni, Shigella, Salmonella, +/- E. coli O157:H7* C. difficile, E. histolytica (protozoa)

6

Pathogens Producing Watery Diarrhea

Vibrio cholerae
Enterotoxigenic E. coli
Rotavirus
Norwalk virus
Giardia lamblia

7

Histology of cholera

Looks normal

8

What is the leading cause of prolonged diarrhea, dehydration from diarrhea, hospitalization from diarrhea, death from diarrhea (U.S. and world)

Rotavirus

9

Vaccine for rotavirus

Live, oral vaccine (>90% effective in US and 17-65% in developing countries)

10

Who gets rotavirus the most?

Infants, young children

5-8 days duration of illness

11

Norovirus

Older children, adults

Family and community epidemics

1-2 day duration of illness

12

Giardia lamblia

Diarrhea, fatigue, abdominal cramps, bloating, malodorous stool, flatulence, weight loss

13

Pathogens Producing Inflammatory Diarrhea (in order of how common they are)

Campylobacter jejuni
Salmonella sp.
Shigella sp.
E. coli 0157:H7
E. histolytica

14

Most common cause of inflammatory diarrhea

Campylobacter jejuni

15

Fecal leukocytes

Can be positive with inflammatory diarrhea and so can give antibiotics

16

E. coli 0157:H7

Vast majority of hemorrhagic colitis in US
2-4 days duration
Highest rates in young children and elderly
Comes in meat

17

Spectrum of illness of E. coli 0157:H7

Asymptomatic infection
Non-bloody diarrhea
Hemorrhagic colitis
Hemolytic uremic syndrome (HUS)
Thrombotic thrombocytopenic purpura (TTP)

18

What causes illness with E. coly 0157:H7?

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

19

What is the leading cause of nosocomial diarrhea?

C. difficile

20

Diagnosis of nosocomial diarrhea

Don't need to do culture or parasite exam

If someone has been in hospital more than 3 days or has been taking antibiotics, think C. diff

21

C. diff

Antibiotic-associated colitis
Nosocomial diarrhea
Toxin A/Toxin B
Antibodies important

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

Fecal transplant

22

Enteric Fever (sites and pathogens)

Site: Nodes; Blood; Gallbladder
Pathogens: Salmonella typhi, S. paratyphi, ±Yersinia

23

Salmonella enteric serotype typhi

Typhoid fever

Gram negative rod; Human only

Cases/year:

24

What's wrong?

College student goes to Mexico for summer vacation, acute, non-inflammatory diarrhea (watery stool, no blood, no fever)

Enterotoxigenic E. coli

25

What's wrong?

Embassy official travels to Peru; enjoys ceviche at a state dinner; does not enjoy acute abd. pain, profuse watery diarrhea (20/day) which develops 2 days later; No fever, blood. Several others ill.

Vibrio cholerae

26

What's wrong?

American trekker in Nepal develops acute abd. pain, bloating, gas, foul-smelling diarrhea. No blood, fever. Does not respond to quinolones; loses 10 lbs.

Giardia lamblia

27

What's wrong?

Embassy official, well-recovered, arrives in Seattle, kisses ground, and, craving real American food, takes family to Jack-in-the Box. Four days later, develops abd. pain, grossly bloody diarrhea. No fever.

E. coli 0157:H7

28

What's wrong?

Physician traveler, anxious about travelers' diarrhea, takes amoxacillin-clavulanate while on CME boondoggle in Tahiti. Develops acute watery diarrhea, mild fever, guaiac positive.

Clostridium difficile