13- GI infections Flashcards
types of liver abscesses
pyogenic, amoebic, hepatic abscesses
C difficile is what type of bacteria
gram positive spore forming bacillus, obligate anaerobe, part of normal gut flora in 1-3% of adults, and 70% of kids<12 months
some strains produce toxins A and B
how long do C diff spores last
> 5 months and are hard to destroy
what is the infective dose of C diff
<10 spores
transmission of c difficile
fecal oral route, person to person in hospitals, reservoirs are humans, environment
do all pts infected with c diff have symptoms
no some with be colonised with no symptoms instead of infected with symptomatic
most common antimicrobials predisposing to CDI
clindamycin ampicillin amoxillin cephalosporins fluoroquinolones -ALSO WITH PPI USE AND RENAL FAILURE
symptoms of c diff
watery diarrhea, loss of apetite, fever, nausea, abdominal pain and cramping
How can you test for C diff infection?
PCR on diarrheal stool
Testing asymptomatic pts is not indicated, testing for cure is not recommended
tx of c diff
metronidazole, standard regime, vancomycin
what is enteric fever
its a severe systemic illness with fever and abdominal pain; due to S enterica serotype typhi
chronic carriage of s typhi definition
is defined as excretion of s typhi in stool or urine>12 months after acute infection (occurs in women, pts with cholelithiasis)
Chronic carriage in the urine is rare and almost always
associated with an abnormality in the urinary tract (eg,
urolithiasis, prostatic hyperplasia) or concurrent bladder
infection with Schistosoma
The S. Typhi carrier state may be an independent risk factor for
carcinoma of the gallbladder as well as other cancers
For CDI surveillance you need to know the definition of a case of CDI, what is the definition
presence of diarrhea AND a stool test positive for C diff/ toxins A/B OR colonoscopic/histopathological findings of pseudomembranes
The best CDI preventative measure are
- decrease # of pts at risk (susceptible)
- decrease # of pts with CDI (reservoirs)
Antimicrobial stewardship reccomendations
Minimize the frequency and duration of antimicrobial
therapy
• Decrease the number of antimicrobial agents prescribed,
• Targeted antimicrobials should be based on the local
epidemiology and the C. difficile strains
• Restrict the use of cephalosporin and clindamycin
• Audit and feedback targeting broad-spectrum antibiotics
What are core prevention strategies for CDI
Contact Precautions for duration of diarrhea
• Hand hygiene (HH) in compliance with CDC/WHO
• Cleaning and disinfection of equipment and environment
• Laboratory-based alert system for immediate notification
of positive test results
• Educate HCP, housekeeping, admin staff, patients,
families, visitors, about CDI
Tip: Routine identification of colonized patients for infection control purposes is not
recommended and treatment of such identified patients is not effective
T/F humans are the only reservoir for S. typhi
T
T/F Pts can develop enteric fever despite having been vaccinated for S typhi
T
the vaccine is not completely effective
Also S Paratyphi causes most of the infections in vaccinated cases because the Vi
polysaccharide typhoid vaccine is ineffective against
most S. Paratyphi , which lack the Vi antigen targeted
by the vaccine
What is the difference between RF for paratyphoid fever and typhoid fever
transmission of paratyphoid fever was more
frequently observed outside the home (eg, via consumption of food
purchased from street vendors); transmission of typhoid fever was
more frequently observed within the household (eg, via sharing
utensils, presence of a patient with typhoid, lack of soap or
adequate toilet facilities)
