Tropical Medicine, Diarrohea, Dysentry

Front 1

Who is at the highest risk for childhood diarrhoea? What virus is the biggest in this group? how many die in developing countries from it?

Back 1

chidren 6-12 months, Rotavirus, 440,000 die (when maternal antibodies wane and their own immune system is still immature)

Front 2

1. Define diarrhoea?
2. Define persistent diarrhoea?
3. Define Dystentery?

Back 2

1. 3 + stools/day, take the shape of the container
2. 2 weeks +
3. + bloody mucous, abdo pain and tenesmus (severe pain when straining to pass stool)

Front 3

Which viruses cause watery diarrhoa?

Back 3

1. rotavirus,
2. adenovirus
3. enterovirus
4. norovirus

Front 4

Which bacteria cause watery diarrhoa?

Back 4

1. e. coli (enterotoxic)
2. vibrio cholerae
3. salmonella
4. shigella (causes dysentry)

Front 5

What does the Cholera bug look like?

Back 5

motile, gram neg. bacillus with a single polar flagellum

Front 6

what are the serogroups of cholera?

Back 6

1. classic: 01. Has serotypes Inaba, Ogawa. Has biotypes: El tor, classic
2. 0139

Front 7

Give an outline of cholera pathophysiology:

Back 7

1. vibrios attach to brush border of small intestine and secrete CHOLERAGEN
2. B (binding) subunit binds a receptor
3. A (active) subunit activates AC (ATP->cAMP)
4. NaCl is inhibited leading to OSMOTIC diarrhea (rice water diarrhea)

Front 8

Give 2 possible outcomes to cholera infection:

Back 8

1. self-limiting and resolves in a week
2. death from hypovolemia and Acute Renal Failure

Front 9

Give 3 host factors that increase the severity of cholera:

Back 9

1. blood group O
2. decreased gastric acidity
3. high infecting dose

Front 10

How is Cholera diagnosed:

Back 10

1. clincial
2. Dark Field microscopy
3. ±florescence microscopy
4. Culture (stool, rectal or anal swabs) on:
-TCBS agar or -taruochlotatetellurite
gelatin agar
-MacConkey's to distinguish e.coli and shigella

Front 11

How is Cholera treated?

Back 11

1. replace fluids (ORS: 1Lwater, 3g salt, 18 g sugar)
2. doxycline/co-trimoxazole/ erythromycin/ciprofloxacin

Front 12

What are the two types of cholera vaccine?

Back 12

1.live-attenuated oral vaccine
2. oral killed whole cell vaccine

Front 13

What does Shigella look like?

Back 13

Gram negative rod, non-capsulated, non sporing forming, non motile "shigella has NO flagella"

Front 14

What is an infecting dose for Shigella?

Back 14

10-100 (VERY low) *higher mortality than cholera

Front 15

Which shigella is the cause of epidemic dystentery (that is also in the developed world?)

Back 15

shigella dystenteriae type 1 (Sd1)

Front 16

What are the 4 groups of shigella?

Back 16

1. S. dysenteriae (group A)
2. S. flexneri (group B)
3. S. boydii (Group C)
4. S. sonnei (group D)

Front 17

Describe a mild illness of Shigella:

Back 17

1. lasts 2-3 days
2. 6-8 stools/day with a bit of blood

Front 18

Describe a sever case of shigella:

Back 18

1. fever, malaise
2. colicky abdo pain
3. many blood stain stools including red current apprearence, though is odorless
4. lasts 2-3 weeks

Front 19

Give 5 complications of shigella:

Back 19

1. dehydration
2. hypotonia
3. protein losing enteropahy
4. perforation
5. toxic megacolon

Front 20

Give 3 extraluminal complications of shigella:

Back 20

1. convulsions (kids)
2. HUS (also in e. coli 0157) and ARF
3. Reiter's syndrome (urithritis, apthosis, ulvers, keritinodermis uritica)

Front 21

How is shigella diagnosed?

Back 21

1. clinical and blood and pus in stools
2. Culture stool on MacConkey's agar
3. sub-culture on salmonella-shigella agar

Front 22

What is Shigella treatment?

Back 22

1. hydration
2. Quinolone
3. ampicillin or co-trimoxazole
4. nalidixic

Front 23

What s the life cycle of amboebiasis (entamoeba histolytica/dispar)

Back 23

1. ingest one cyst
2. Excystation in small intestine which releases the TROPHOZOITES and causes local necrosis
3. ulcer forms and hematogenous spread is possible
4. cysts are excreted to continue the cycle

Front 24

What are the three possible clinical pictures of amoebiasis infection?

Back 24

1. asymptomatic (90%)
2. locally invasive (10%)
3. extraintestinal (1%) (liver, brain)

Front 25

describe 5 features of fulminant dysentery from amoebiasis in malnourished/immunocompromised:

Back 25

1. blood, foul smelling diarrhea
2. fever, weakness
3. vomitting abdominal pain
4. peritonitis ± toxic megacolon
5. amoeboma may occur (granuloma)

Front 26

what does anchovy sauce paste describe?

Back 26

pus from amoebic liver abscess

Front 27

what are the signs/symptoms of amoebic liver abscess?

Back 27

pain over liver
hepatomegaly
fever
cough
edema/tension in skin near the abscess

Front 28

A. what are the possible complications of amoebic liver abscess? (5)
B. how is it diagnosed?

Back 28

A. Rupture
1. cutaneous sinus
2. amoebic empyema
3. hepatobronchial fistula
4. amoebic peritionitis/pericariditis
5 metastatic disease to the lung or brain
B. U/S, CT, serology ALA

Front 29

How is amoebiasis diagnosed?

Back 29

1. look at stool
2. test stool for E. histolytic specific ag (good but expensive)

Front 30

What is treatment for amoebiasis:
1. non-invasive
2. invasive

Back 30

1. diloxanide furoate
2. metronidazole followed by diloxanide furoate

Front 31

What are symptoms of a giardia lamblia infection?

Back 31

1. mostly asymptomatic
2. anorexia, nausea
3. chronic diarrhoea, cramps, bloating, weight loss, failure to thrive
4. immunocomp: severe and malabsorption

Front 32

How is giardia diagnosed?

Back 32

cysts in stool
string test
aspirate
stool antigen detection

Front 33

treatment for giardias:

Back 33

metronidazole or tindinazole