acute infectious diarrhea Flashcards
clin med
major cause of death in infectious diarrhea
dehydration
sx of enterotoxin-producing bacterial infection
small bowel hypersecretion –>
profuse, watery diarrhea
marked vomiting
min fever
occurs abruptly within a few hours after ingestion
sx of enteroadherant pathogens causing infectious diarrhea
small bowel hypersecretion–>
mild vomiting
high levels of abd cramping + bloating
high fever
sx of cytotoxin producing and invasive microorganisms causing infectious diarrhea
high fever
abd pain
5 high risk groups for infectious diarrhea
travelers immunodeficient daycare families institutionalized (assisted living) consumers of certain foods
what agents are daycare workers/attendees/ and families especially at risk of being infected by
shigella
giardia
cryptosporidium
rotavirus
signs of mild, mod, and severe dehydration
mild= thirs, dry mouth, less sweating and urination, weight loss
mod= orthostatic fall in BP, skin tenting, sunken eyes
severe= lethargy, obtundation, feeble pulse, hypotension, shock
most cases of acute infectious diarrhea are ___ and ____, so you ____ do an extensive work up
mild
self-limited
dont need to
explain the steps in treating infectious diarrhea
first find if it is likely infectious
(Y or N, still treat w fluid and electrolyte replacement)
if mild diarrhea, just observe until further proof
(then trx with plan for severe)
if mod diarrhea, but not other systemic sx then just give them antidiarrheal agents
if severe OR mod with (F>38,bloody stools, increased fecal WBC, x immunity, or old person) OR persistent mild diarrhea—> get a stool study and treat w specific/empirical trx
indications for evaluation of infectious diarrhea
profuse with dehydration hypotension and tachy not responsive to volume repletion dysentery fever > 38.5 duration >48 hrs w no improve recent abx use (bc c dif) severe abd pain >70 immunocompromised cr > 1.5xnormal peripheral leukocytes >15k
what organisms can be caught on a routine stool culture
salmonella
shigella
E. Coli
campylobacter
takes 24-48 hours
what organisms do you need to specifically get a stool bacterial culture to be able to see?
EHEC E Coli (specifically ask for shiga like toxin)
vibrio
yersinia
what organisms do you need to specifically get a stool immunoassay to be able to see?
C. Dif PCR/toxin
what organisms do you need to specifically get a stool protozoal Ag to be able to see?
giardia
cryptosporidium
E. hystolitica
what organisms do you need to specifically get a stool viral PCR/Ag to be able to see?
rotovirus
norwalk/norovirus
if stool studies are unrevealing for infectious diarrhea, what can you do next
endoscopy w biopsy
why should you order an xray with infectious diarrhea
with an abd xray you can check for free intraperitoneal air, ileus, or toxic megacolon, all of which could be complications of bacterial infection
what time of year and what situational context should make you consider bacterial diarrhea/food poisoning
summer time, food be sitting out a long time
after multiple illnesses reported after a shared meal
what bacterial agents can be caused by eating infected chicken
salmonella
campylobacter
shigella
what bacterial agents can be caused by eating infected undercooked hamburger
EHEC
what bacterial agents can be caused by eating infected fried rice
bacillus cereus
what bacterial agents can be caused by eating infected potato salad, mayo, or cream pastries
staph aureus
what bacterial agents can be caused by eating infected eggs
salmonella
what bacterial agents can be caused by eating infected lunch meat, soft cheese
listeria
what bacterial agents can be caused by eating infected seafood
vibrio, salmonella, acute Hep A, norovirus, campylobacter
what bacterial agents can be caused by eating infected beef, ham, legumes, gravy
C. perfringens
microbio of staph aureus
G+ cluster, has preformed enterotoxins
sx and trx of staph aureus infectious diarrhea
N/V, watery diarrhea, within 6 hours of ingestion
trx= rapid resolution within 1-2 days
microbio of bacillus cereus
G+ rods, preformed enterotoxins
sx and trx of bacillus cereus infectious diarrhea
mainly vomiting, some watery diarrhea within 6 hours of ingestion
trx= rapid resolution within 1-2 days
microbio of C perfringens
G+, heat resistant spore forming Rod
preformed enterotoxins
sx and trx of C. Perfringens
watery diarrhea and cramping abd pain, onset within 8-16 hours of ingestion
trx= rapid resolution with 1-2 days
most common type of shigella in the US
shigella sonnei, subgroup D
classic cause of dysentery:
beginning with watery diarrhea w blood and pus—> bloody diarrhea
shigella
sx and diagnostic tools for shigella
watery diarrhea —> dysentery
small volume diarrhea
abd cramps
fever 3-4 days
dx= + fecal leukocytes, stool cultures ~ to IBD, lactose -
trx for shigella
bismuth, ampicillin, flouroquinolones, or trimethoprim/sulfamethoxazole
sx of salmonella typhimurium
watery –> bloody diarrhea, 5-10 days
fever, abd cramping, N/V, fecal leukocytes (+)
trx for salmonella typhimurium
is self limited to 5-10 days and abx not indicated
reptile exposure (spec. = turtles) can lead to infectious diarrhea caused by
salmonella typhimurium
what are the two sx phases in typhoid fever
- sustained febrile illness, 103-104 w weakness, HA, anorexia, “pea soup”, foul-smelling diarrhea –> bloody diarrhea, rose colored spots on skin
asx hitus
- bacteremia –>encephalopathy, splenomegaly, brady+dicrotic pulse, conjunctivitis, intestinal perforation, intestinal hemorrhage
dx and trx for salmonella typhi
ds= stool and blood cultures, fecal leukocytes +
trx= prevent with hand washing and good food prep
flouroquinolones, ceftriazone, azithromycin
sx of C. jejuni
watery–> bloody diarrhea
fever
crampy abd pain
erythema nodosum
microbio of C jejuni
G- curved/spiral shaped rod,
dx and trx of C jejuni
dx= fecal leukocytes +, stoolcultures NEED CAMPY BLOOD AGAR
trx= self limited to a 1 week, so just give supportive care
dx test for cholera
stool microscopy and gram stain
see rods darting around
what organism are you at risk of being infected by with raw oysters and/or salt water infected in sewage
cholera
virbio vulnificus
microbio of vibrio parahemolyticus
G- bacilli, cytotoxin production
sx of V. parahemolyticus
N/V, cramps, watery–>bloody diarrhea, 2-5 days
dx and trx of vibrio parahemolyticus
dx=fecal leukocyte +, stool culture request special
trx- self limited
microbio of vibrio vulnificus
G- bacillus
sx of vibrio vulnificus
= vomiting, diarrhea, abd pain within 16 hrs of ingestion
ballous skin lesions aka necrotic
is life threatening in an immunocompromised person, especially w cirrhosis and hemochromatosis
microbio of A. hydrophila
G-, non-spore forming, rod shaped, motile
sx of A. hydrophila
two types=
cholera like= watery rice water stools
or bloody mucoid stools
often wounded in fresh water env at the foot ankle, can rapidly progress to narcotizing fascitis
trx for A. hydrophilia
ampicillin
what is a classic presentation of someone with A. hydrophila
a scuba diver that swallows small amounts of fresh water and then has gastroenteritis
any fresh or brackish water, either eating fish or getting wounded in the water
what risk factors can make someone vulnerable to contracting traveler’s diarrhea
H2 blocker/PPI
most common pathogen for traveler’s diarrhea
ETEC
infection commonly associated with visits to Russia, and campers
giardia
infection commonly associated with cruise ships and daycares
norovirus
microbio for ETEC
G- rod
dx for ETEC
last 3-6 days
fecal leukocyte is (-)
diagnose clincally bc stool cultures don’t differentiate between strains of E. Coli
trx for E Coli
abx that can reduce infection time
trimethoprim/sulfamethoxazole/doxycycline, ciproflaxaxin
sx of EHEC infections
watery —> bloody diarrhea
acute hemorrhagic colitis
typically NO fever
dx for EHEC and trx
CBC to check for leukocytes, anemia, thrombocytopenia
fecal leukocytes (+)
fecal lactoferrin (+)
trx= supportive care, rehydration, NO GIVE ABX or else get HUS only give abx if they’re actually about to die
what populations have a high risk of yersinia infection
derangements of iron metabolism enhances virulence soo –> cirrhosis, hemochromatosis, aplastic anemia, thalassemia, DM
microbio of listeria
G+, can grow in the cold
risk factors for listeria infections
pregnancy
extremes of age and immunocompromised
contaminated deli meats
pregnant lady eats cheese
dx and trx for listeria
need blood cultures
trx= ampicillin and TMP/SMX
trx for T. whipplei (G+)
= whipple ds
abx therapy, prolonged trx for a year is required
cross the BBB- first cetriaxone, meropenem, followed by TMP/SMX
after trx, do repeated duodenal biopsies +spinal tap for at least a year to make sure its gone
microbio of C. Dif
anaerobic, G+, spore forming bacillus that is exotoxin mediated
dx for C. Dif
stool assay, PCR for toxin A or B
+ peripheral leukocytosis
pseudomembranes seen on sigmoidoscopy
which drugs specifically have higher risk of C Dif infection
clindamycin
cephalosporins
flouroquinolone
trx for c dif
PO/IV metronidazole
PO vancomycin
what is a very serious complciation of c dif infection
toxic megacolon, with 60% mortality, needs aggressive trx and surgery consult
most common nosocomial infections
C Dif, norovirus
sx and stool findings in a case of proximal small bowel infection
watery diarrhea
(-) fecal leukocytes, no increase in fecal lactoferrin
sx and stool findings in a case of colon or distal small bowel infection
dysentery/inflammatory diarrhea
fecal polymorphonuclear leukocytes
increase in fecal lactoferrin
sx and stool findings in a case of distal small bowel infection
enteric fever
fecal mononuclear leukocytes`
sx, dx, and trx for rotavirus
sx= [6 months–>2 year olds] vomiting and watery diarrhea –>severe dehydration
self limiting usually,
dx= (-) fecal leukocytes, detected by viral culture/PCP, ECM shows wagon wheel appearance
trx= support and vaccinate
dehydration–>death
adenovirus population
children, second most common cause of gastroenteritis in children (after rota virus)
sx, dx, and trx of adenovirus infection
high fever (103-104), myalgia, watery diarrhea, conjunctivitis, 10 day course, pharyngitis
dx= viral culture
trx- support
population at risk for noro
older children and adults
sx, dx, and trx for norovirus
sx= vomiting, watery diarrhea, lasting 3 days
dx= (-) fecal leukocytosis, routine viral cultures, need a work up
trx= supportive care
population associated with CMV infection
immunosuppressed
sx and dx of CMV
fever, blood diarrhea for several weeks
dx= endoscopy w biopsy of ulcerated lesions using CMV specific stains
dx of E histolytica
flask shaped ulcer on histology,
stool for ova & parasite
stool Ag
fecal leukocytes (+)
acute narcotizing colitis
trx for E. hystolytica
eliminate the invading trophozoites (metronidazole or tinidazole)
eradicate intestinal carriage –> paromomycin or iodoquinol
microbio of giardia
pear shaped, 4 flagella
sx, dx, and trx of giardia
sx= watery smelly diarrhea, weight gain, flatulence, steatorrhea, malase,
dx= fecal leukocytes (-), ova parasites, stool Ag detection
trx= tinidazole, metronidazole
recurrence is common
clinical presentation of cryptosporidium parvum
in immunocomp ppl= self limited dairrhea (1-2 weeks(
in immunosuppressed, life threatening and possible indefinate
> 20 L of watery diarrhea a day
what organism are you at risk of bring infected by in a public pool
cryptosporidium
dx and trx of cryptosporidium
dx= stool Ag or modified acid fast stainig, DFA (direc flourescence Ab) fecal leukocytes (-)
trx= resistant to chlorine trx,
hydration,
loperamide, nitazoxsnide, trx AIDS if present
those infected with HTLV-1 are more susceptible to infection by
strongyloides stercoralis
sx, dx, and trx of strongyloides stercoralis
sx= often asx, or bloating, V/D, perianal urticaria, migratory rash
dx= rhabditiform larvae in stool
trx= anti-helmintic
what organism are you at risk of bring infected by from imported produce (basil, raspberries)
cyclospora cayetanensis
sx, dx, and trx of cyclospora cayetanensis
sx= low grade fever, watery dairrhea, anorexia lasting up to 21 days if immunocomp, indef if immunosupp
dx= fecal leukocyte (-), detect oocyte in stool
trx= TMP/SMX
cystoisospara belli sx, dx, and trx
sx= acute watery diarrhea, crampy abd pain, malabsorption and weight loss
can be v severe in immunosupp, infants, and children
dx= repeated stool exams and concentrations, if (-) do a duodenal biopsy, visualize oocytes on wet mount or acid fast stain
trx= prevent, bactrim DS (TMP/SMX)
soil transmitted hookwork that is ingested fromthe soil and can get really long to cause bowel obstruction
ascaris lumbricoides
fish tapeworm from raw fish that can grow up to 30 ft and cause B12 deficiency
diphyllobothrium latum
consequences of vit B12 deficiency
pernicious anemia and neuro sx
most common infectious cause of esophageal varices in africa
most common cause of small portal V branch obstruction
method of infection and sx and trx
schistosoma mansoni
from contaminated freshwater snails, cause bloody stools, bladder CA and liver cysts
trx= praziquantel
pork tapeworm, cause seizures and muscle or eye ds
taenia solium
beef tapeworm, mostly asx
taenia saginata
tapeworm from unsanitary sheep slaughter or dogs
complications
echinococcus granulosus
form cysts in liver or lungs
looks like free-flowing “hydatid sand” on CT
E. vermicularis sx, dx, trx
(pinworm)
severe perianal itching
scotch tape test
trx= mebandazole
when can anti-motility trx be used to treat infectious diarrhea
what two organisms can you NOT use anti-motility agents for
in patients with
NO fever
NON-bloody stools
C. dif and EHEC
nutrition and diet recommendations for infectious diarrhea
BRAT diet (banana, rice, applesauce, toast)
easily digestible foods
rice water
avoid lactose and high fiber foods
what two agents are hand sanitizer ineffective against
norovirus
c. dif
WASH YO HANDS BIOTCH
what organisms can be vaccinated against
rotavirus
s. typhi
v. cholera
hep A
what prophylaxis can be given to travelers to avoid travelers diarrhea
bismuth subsalicylate (s.e. of dark tongue and stools)
abx prohylaxis= cirprofloxacin, azithromycin, rifaximin
what agents can cause reactive arthritis aka reiter’s syndrome
reiter’s syndrome= arthritis, urethritis, conjunctivitis (cant see, cant pee, can’t climb a tree)
salmonella, campylobacter, shigella, yersinia
complications of yersinia infection
yersiniosis
autoimmune type thyroiditis
pericarditis
glomerulonephritis
what organisms can lead to HUS? prognosis?
EHEC (O157:H7)
shigella
high mortality rate, with microangiopathic hemolytic anemia, thrombocytopenia, renal insufficiency
differentiate between the sx of a small bowel infection and a colon infection
small bowel= watery stool, dehydration/malabsorp, weight loss, NO WBCs in stool, pain either diffuse or in midabd
large bowel= frequent small volume stools, blood or WBCs in stool, lower abd/rectal pain
organism with high infection in IgA deficiency
giardia
people with hemochromatosis are at higher risk for infection by
vibrio species
listeria
yersinia
AIDS pts are more susceptible to…
mycobacteria
CMV, adenovirus, herpes
cryptosporidium, C. belli, microsporida, B. hominis,
N. gonnorrhea, T. pallidum, chlamydia
once salmonella typhi infects the ___, you become a carrier
GB
infants with watery or bloody diarrhea are likely to have
which histologically looks like
EPEC
loss of villi= ephacement
non-bloody persistent diarrhea without a fever
more severe in immunocompromised
EAEC
young kids in developing countries with fever, pain, dysentery
EIEC
sx of C. dif
dehydration
hypoalbuminia
fever
waterry, smelly diarrhea
hangs out on heart valves –> heart murmur
steatorrheacommon in white farmers
whipple ds
the rotavirus vaccine is linked to ____, and is contraindicated in _____ patients bc it is a live vaccine
intussusception
immunocompromised
most common cause of viral conjunctivitis in kids
adenovirus
sx of e histolytica
abd pain bloody diarrhea weight loss necrotizing colitis megacolon
