Brown: Clinical Aspects of Urinary Tract Infections Flashcards
Significant Bacteriuria definition:
What concentration in symptomatic patients?
> 105 cfu/mL of urine (only needs to be 102 cfu/mL in symptomatic patients)
Asymptomatic Bacteriuria:
Significant bacteriuria in the absence of any symptoms suggestive of UTI
Cystitis (Lower UTI):
Infection confined to superficial bladder mucosa
Pyelonephritis:
Infection that involves the renal parenchyma
Uncomplicated UTI:
Cystits or pyelonephritis that occurs in an otherwise healthy, non-pregnant woman with no underlying structure or functional abnormality of the urinary tract
Complicated UTI:
Full list, don’t memorize
Associated with any of the following
o Obstruction: of any site of the urinary tract (enlarged prostate, uterine/bladder prolapsed, stones, tumor)
o Foreign body: catheter or stent
o Incomplete voiding: detrusor muscle dysfunction (neurologic disease, medications)
o Vesicoureteral reflex: urine travels up the ureters instead of out the urethra (usually only in kids)
o Recent history of instrumentation/invasive urologic procedure
o Renal transplant recipient: always classified as complicated
o Male: always classify as potentially complicated
o Pregancy: always classified as complicated
o Diabetes
o Immunocompromise
o Health-care associated infection
o Multi-drug resistant infection
Recurrence:
Relapse or reinfection (most often)
Relapse:
Recurrence due to the same microorganism (not completely eradicated; within 2 weeks)
Reinfection:
Recurrence due to a different microorganism (usually after 2 weeks)
How common?
Extremely common:
- Second most common CA infection
- Most common health care associated infection (CMS no longer reimburses hospitals for costs due to UTIs because they are seen as preventable)
Most common source of what type of bacteremia?
What can childhood UTIs cause?
Can cause bacteremia: most common source of Gram negative bacteremia
Can cause chronic renal failure: early childhood UTIs
What is Vesicoureteral reflex and in what population is it found?
Vesicoureteral reflex: urine travels up the ureters instead of out the urethra (usually only in kids)
Prevalence by Age Group
Infant:
1-15 years:
Infant: more common in males than females, although rare in general
1-15 years: more common in females (4-5%)
Prevalence by Age Group
16-35 years:
36-65 years:
16-35 years: more common in females (increases to 20%- sexual activity)
36-65 years: more common in females, but males also increase (due to benign prostatic hypertrophy)
Prevalence by Age Group
65+ years:
65+ years: still more common in females, but very high rates in both genders (again, mainly due to BPH)
Natural History of UTI
In Pregnancies:
Resolve without treatment?
Asymptomatic bacteriuria occurs in some pregnancies and many of those will develop pyelonephritis during pregnancy if untreated
Symptomatic and asymptomatic UTIs will resolve without treatment, but antimicrobial therapy increases probability of cure and speeds symptom resolution.
Bacteria originating in intestine normally colonize:
Bacteria originating in intestine normally colonize vaginal introitus, periurethra and distal urethral meatus
What are uropathogenic E.coli members of?
Where do they typically reside?
How does UPEC compare to commensal E.coli?
exPEC group
Reside in the gut without consequences. Can disseminate to/colonize extra-intestinal sites
Compared to commensal E.coli UPEC are more likely to harbor genes linked to virulence