infectious diarrhea and CDI Flashcards
definition of acute infectious diarrhea
passage of loose or watery stool >=3 times in a 24h period that lasts for <14 days
sources of infectious diarrhea
- international trvel
- food or water borne
- exposure to infeced animal or feces
- recent antimicrobial use
how is acute infectious diarrhea trasnmitted
likely fecal to oral route
what diagnositic testing is doen for acute infectious diarrhea
- lab test not routinely done
- rec in pt with diarrhea with fever, bloody or mucoid stools, severe ab cramping or tenderness, signs of sepsis
- test of salmonella, shigella,cD…
stool culture and PCR done
when is ab tx recommended for acute infectious diarrhea?
- pt has severe disease (fever, bloody or mucoid stools, severe ab cramping or tenderness)
- pt appears septic
- pt is immunocomprimised host
what is the empiric therapy for AID?
- Ceftriaxone 2g IV q24h
or - ciprofloxacin 500mg PO BD
for 3-5 days
what is Clostridioides difficile(C.diff)
- gram pos, anaerobic, sport forming, otxin producing bacillus
- colonize intestinal tract
how iare c diff infections caused
facilitated by disruption of norma; intestinal flora
often due to ab therapy
what are the clinical manifestations of CDI
- diarrhea without colitis: >= 3 ep of unformed stools in 24h
- colitis: fver, ab pain, nausea, anorexia
- severe colitis: sepsis, sig leukocytosis, renal impairment
- fulminant colitis (severe + complicated): eg. toxic megacolon, colonic perforation, intestinal paralysis
risk factors of cdi
pharmacotherapy
- number and days of systemic concomitant ab use
- high risk ab (eg. clindamycin, FQ)
- PPI
past healthcare exposure
- prior hospitalisation
- duration of hospitalisation
- long term care residnecy
host immunity
- lack of ab response to65 yo
C c diff toxin
- severity of underlying illness
- comorb
increasing age
- >65 yo
CDI experience
- prior CDI infection
risk factors of cdi
antibiotic
- highest risk during ab tx and 1 month post
- high risk ab: clindamycin, 3/4th gen cephalosporin, FQ
- exposure dep: number, dose and duration of ab
ppi
- reduction of gastric acid may allow ingested c diff to survive
- discont. unnec ppi
diagnosis of cdi
- unexplained and new onset diarrhea
AND
positive stool test result for toxigenic c diff or its toxins
what are the 3 major tests done to diagnose cdi?
- glutamate dehydrogenase GDH EIA: detect c diff common antigen
- toxin A and B EIA: detect toxins a and b
- nucleic acid amplication tests (NAAT): detects c diff toxigenic genes, may detect colonisation and not true cdi
how is CDI transmitted
- likely fecal to oral route
- healthcare setting: exposure to contaminated envr or hands of healthcare personnel, transiently contam with spores
how is cdi controlled
- isolatio measurs for infected pt
- appropriate PPE when caring for infected pt
- practice good hand hygeien before and after contact with pt
- infection control strategies implemented ine every suspected case, not only confirmed
envr management
- sporicidal disinfectant to cleanse reusable equipment
antimicrobial stewardship
- minimise freq and duration of high risk ab therapy
tx for initial episode, non severe CDI
- vancomycin (VAN) 125mg PO q6h for 10 days
- fidazomicin (FDX) 200mg PO q12h for 10 days (not not registered in sg)
alt tx
- metronidazole 400mg PO q8h for 10 days
tx for initial episode, severe CDI
- VAN 125mg PO q6h for 10 days
- fidazomicin (FDX) 200mg PO q12h for 10 days
- metronidazole NOT REC
tx for initial episode, fulminant CDI
- VAN 500mg PO q6h by mouth or NG tube
- metronidazole 500mg IV q8h
if ileus:
- combi of VAN and metronidazole rec
- consider adding PR VAN 500mg in 100ml NS PR q6h (rectal instillation via enema)
what are some advantage of fidaxoamicin vs other CDI tx
- display narrow sepc of activity
- bactericifal (VAN is bacteriostatic)
- lower MIC agaisnt c diff
- prolonged post ab effect, require less frequent dosing
- higher rate of sx cure with FDX
- FDX assc with lower CDI recurrence rate
diadvantage of FDX
- expensive
- limited data to support use in complicated cdi
- not registered in sg
tx of recurrent episodes of cdi
first recurrence
if metronidazole was used for initial
- VAN 125mg PO q6h for 10 days
if vAN of FDX used
- prolonged tapered or pulsed VAN regimen:
VAN125mg PO q6h x 10-14 days ==>
Van 125mg PO q12h x 7 days==>
VAN 125mg q24h x 7 days ==>
VAN 125mg PO every 2-3 days for 2-8 weeks
if VAN was used for initial
- FDX 200mg PO q12h for 10 days
tx of recurrent episodes of cdi
2nd/3rd recurrence
- tapered for pulsed VAN regimen
- VAN 125mg PO q6h x 10 days followed by rifaximin 400mg PO q8h x 20 days
- FDX 200mg PO q12h for 10 days
if failed appropriate ab therapy (for >= 2 recurrences)
- fecal microbiota transplantation: restore gut microbiata diversity via instillation of healthy donor stools into GIT of pt with recurrent cdi
how do we monitor therapy of cdi
assess for resolution of sx
- improvement in diarrhea freq and consistency (within few days of initiating tx with near complete resolution within 10 days)
- resolution of leukocytosis
- not rec to repeat stool testing to assess cure (significant proportion woudl test psoitive despite improvement)
