B5-007 GI Infections Flashcards
causes of acute viral gastroenteritis
3
- norovirus
- rotovirus
- adenovirus
non-bloody, non-inflammatory diarrhea
fecal leukocyte negative
acute viral gastroenteritis
“winter vomiting disease”
norovirus
SS RNA, linear, non-enveloped
norovirus
frequently associated with food service workers
norovirus
food service workers should avoid handling food for […] after resolution of symptoms
2 days
at risk populations for norovirus
close quarters
* military
* cruise ships
* dorms
* school age children
can withstand freezing, heating, chlorine, alcohol
norovirus
DS RNA, segmented, nonenveloped
rotavirus
late winter/early spring
peaks in early march
rotavirus
at risk populations for rotavirus
children under 5
particularly 6 mo-2 years
causes villous destruction and atrophy leading to decreased Na+ absorption and loss of K+
rotavirus
who should be vaccinated for rotavirus?
ALL infants except those with hx of intussusception or SCID
is the rotavirus vaccine live attenuated?
yes
DS DNA, linear nonenveloped
adenovirus
which adenovirus serotypes cause gastroenteritis?
40, 41
other clinical manifestations include conjunctivitis, upper and lower RTIs, and hemmorhagic cystis
adenovirus
which populations are at risk for adenovirus?
children
which protozoa covered is not free living?
trichomonas
eosinophilia absent indicates..
protozoal infection
active feeding forms of protozoa
trophozoites
environmentally resistant forms of protozoa
cysts
preferred method of diagnosis for giardia and cryptosporidium
stool antigen (ELISA)
what diagnostic test may be useful for entamoeba?
serum antibody
pretty much useless for anything else though
- bloody diarrhea
- RUQ pain
- anchovy paste liver abscess
name the protozoa!
entamoeba histolytica
flask shaped ulcer on colon biopsy
name the protozoa!
entamoeba histolytica
entamoeba eats […]
erythrocytes
trophozoites ingest RBCs
treatment for entamoeba histolytica
metronidazole
(asymptomatic cyst passers: paromomycin, idoquinol
pregnancy: paromomycin)
aka Beaver Fever due to association with campers/hikers drinking freshwater
giardia lamblia
- bloating
- flatulence
- foul smelling, fatty, non-bloody diarrhea
giardia lamblia
ghirardelli makes me fat = giardia fatty diarrhea
treatment for giardia lamblia
metronidazole
in immunocompetent hosts, presents with mild watery diarrhea
but in AIDS patients presents with severe diarrhea with wasting
cryptosporidium
associated outbreaks with pools and water parks, daycares
cryptosporidium
treatment for cyptosporidum
prevention
nitazoxanide
if AIDS -> ART
- abrupt onset
- watery diarrhea, explosive
- nausea, ABD cramping
protozoa
cyclospora
recent outbreaks associated with berries and herbs
cyclospora
treatment cyclospora
trimethoprim-sulfamethoxazole
5 micrometers
cryptosporidium
10 micrometers
cyclospora
- watery diarrhea
- nausea, ABD cramping
- AIDS patients -> chronic diarrhea with wasting
- occular keratoconjunctivitis
microsporidia
2 micrometers
microsporidium
treatment microspordia
albendazole
fumagillin
- foul smelling, green discharge
- itching, burning
trichomonas vaginalis
- cannot exist outside of humans
- STI
trichomonas vaginalis
does not form cysts
- diagnosed via wet mount or molecular testing
- molecular testing is superior
trichomonas vaginalis
punctate cervical hemorrhages
strawberry cervix
trichomonas vaginalis
treatment for trichomonas vaginalis
metronidazole for both partners
screen for other STIs
> 3 loose or watery stools in a 24 hour period
diarrhea
- visible blood or mucus in diarrhea
- associated with fever, abdominal pain
dysentery
less than 14 days duration
acute diarrhea
15-30 days duration
persistent diarrhea
greater than 30 days duration
chronic diarrhea
incubation period <6 hours
symptom duration 24 hours
lots of vomiting
indicates…
preformed toxins
incubation period 1-2 days
symptom duration 2-4 days
some vomiting
leukocyte/lactorferrin negative
RBCs negative
viral
incubation period 1-2 days
symptom duration 5-7 days
no vomiting
leukocyte/lactorferrin +/-
RBCs +/-
maybe fever
baterial
incubation period days-weeks
symptom duration weeks-months
leukocyte/lactorferrin negative
RBCs negative
protozoal
except ameibiasis which can cause dystentery
cause classic case of toxigenic gastroenteritis due to fried rice
2
S. aureus
B. cereus
if the patient has been in the hospital more than 3 days, think…
C. diff
transmitted commonly by food service workers
norovirus
unwashed produce may lead you to think..
cyclosporidium
contaminated ice in drink may lead you to think…
crypto
- vomiting
- non-bloody diarrhea
- symptoms resolve about 36 hours
- friends with same virus
norovirus
- non-bloody, non inflammatory diarrhea
- +++vomiting
- short duration
acute viral gastroenteritis
SS RNA linear non enveloped
norovirus
are enveloped or non-enveloped viruses more environmentally stable?
non-enveloped
DS RNA, non enveloped
Rotavirus
DS DNA, non enveloped
adenovirus
associated with water parks
cryptosporidium
4-6 micrometers
cryptosporidium
cryptosporidium oocysts are […] mm
4-6
cyclospora oocysts are […] mm
8-10
large, pear shaped binucleate trophozoites with flagella
giardia
giardia infections are transmitted by consumption of the […] form
cyst
associated with animal contact, recreational water, and day care centers
cryptosporidium
consumption of contaminated cilantro could be associated with
cylospora
GI disease acquired from local drinking stream
giardia
- foul smelling diarrhea
- flatulence
- camping
giardia
what kind of test is superior for giardia?
antigen
microspordia is about […] mm
less than 2
severly immunocompromised individuals are at risk of developing chronic diarrhea and wasting due to
microsporidia
HIV is most commonly associated with
microsporidia
why is the rotavirus vaccine contraindicated in SKID patients?
live attenuated
cyclospora
cryptosporidium
and microsporidium oocysts are all
acid-fast
