B8.046 Urinary Tract Infections in Females Flashcards
lower UTI
cystitis, urethritis, prostatitis
upper UTI
pyelonephritis, intra-renal abscess, perinephric abscess
cystitis
clinical syndrome of inflammation or infection of the urinary bladder
uncomplicated UTI
infection in healthy patient (female) with functionally normal urinary tract
complicated UTI
infection associated with anatomic/functional abnormality of the urinary tract, immunocompromised host, or multi drug resistant bacteria
also UTIs in males
pyelonephritis
infection of kidney that tends to arise from an ascending UTI (fever, flank pain)
asymptomatic bacteriuria
2 consecutive clean catch midstream urine samples growing 10^5 CFU isolation of same bacterial strain in the absence of symptoms
characteristics of uncomplicated UTIs
normal urinary tract both functionally and structurally majority are healthy women sexually active community acquired respond to therapy
characteristics of complicated UTIs
structural or functional voiding abnormalities urinary tract obstruction male pregnancy diabetes mellitus immunosuppression childhood UTIs recent antimicrobial use indwelling catheter urinary tract instrumentation nosocomial UTI
epidemiology of UTIs
50% of all women, 12% of all men in their lifetime
within 6 mo of initial, 20% of women will have a recurrence
genetic risk factors for UTI
immune receptor polymorphisms
urothelial receptor density
family history
biological/physiological risk factors for UTI
anatomic factors vaginal factors/hormonal status urinary obstruction urinary stasis urolithiasis immunocompromised pregnancy SCI catheterization
behavioral risk factors for UTI
functional stasis
sexual intercourse
birth control practices (spermacide/diaphragm)
how does hormonal status impact UTI risk
postmenopausal women experience more vaginal atrophy
lactobacilli stop growing due to changes in pH, allows e.coli to grow more easily
give vaginal E to prevent this
common causative pathogens in adult UTIs
e.coli (80%) klebsiella, enterobacter proteus pseudomonas staph sapro (5-15%) enterococcus candida adenovirus type 11
normal perineal flora
lactobacillus corynebacteria staphylococcus streptococcus anaerobes
ascending route theory
spread is via ascention of urinary tract, not by hematogenous or lymphatic spread
things that contribute to ascension
reduced urine flow
factors that promote colonization
facilitation of ascent
bacterial factors
bacterial factors that aid in pathogenesis of uropathogenic e.coli
bacterial adhesions
phase variation
bacterial adhesions
type 1 pili: mediate binding of uroplakins, mannosylated glycoproteins on the surface of uroepithelial cells (bladder binding)
P pili: bind to galactose dissacharide on the surface of uroepithelial cells and P blood group antigen on RBCs (kidney binding)
phase variation
type 1 pili increase susceptibility to phagocytosis, P pili block phagocytosis
type 1 down regulated , type P upregulated in strains that cause pyelonephritis
clinical signs of cystitis
new onset urinary frequency + dysuria without vaginal discharge is diagnostic (PPV 90%)
+/- urgency, suprapubic pain, hematuria
clinical signs of pyelonephritis
fever, chills, flank pain
urine testing procedure in UTI
midstream, clean catch
UA
urine culture + sensitivities (not necessary if uncomplicated)
dipstick UA findings
leukocyte esterase + indicates presence of 5-15 WBC/hpf
nitrite + indicates presence of bacteria that convert nitrates > nitrites
urine microscopy findings
lots of squamous cells = bad specimen
pyuria (>10 WBCs/hpf) is most sensitive for UTI
bacteria count 5/hpf
WBC casts sensitive for pyelonephritis
quantitative urine culture findings
obtain in patients you suspect have pyelonephritis, recurrent UTI, or complicated UTI
10^2-10^5 CFU/mL is considered diagnostic for UTI
primary treatments for uncomplicated cystitis
nitrofurantoin 100 mg BID x 5 days
TMP/SMX DS BID x 3 days
fosfomycin 3 g x 1 dose
alternative treatments for uncomplicated cystitis
ciprofloxacin or levofloxacin x 3 days
B-lactams x 3-7 days
indications for admission
if a patient appears toxic (fever, tachy, hypotensive)
UTI in context of obstruction (stone) is a urologic emergency
inability to tolerate oral hydration
complicating comorbidities
immunocompromised state
elderly/disabled
indications for imaging
complicated UTI persistence of hematuria after infection treated sepsis from urinary source history of urolithiasis neurogenic bladder poor response to therapy infections with urea-splitting bacteria recurrence with the same or unusual strain
treatment for uncomplicated pyelonephritis
fluoroquinolones x 7 days
TMP/SMX DS BID x 14 days
oral b-lactam x 14 days
why can you not use nitrofurantoin for pyelonephritis
BAD TISSUE PENETRATION
definition of recurrent UTI
3 UTIs within 12 mo or 2 UTIs within 6 mo
what do you focus on with patients with recurrent UTIs
prevention look at: relationship to sex sexual practices history of childhood UTIs history of voiding dysfunction/constipation history of stones history of anatomic abnormalities
evaluation of a patient with recurrent UTI
pelvic exam to check for urethral diverticulum, atrophic vaginitis
urine cultures mandatory
upper tract imaging usually completed
+/- cystoscopy depending on risk factors
behavioral counseling for recurrent UTI prevention
discontinue use of spermacide and/or diaphragm avoid douching post coital voiding timed/double voiding constipation management
biological mediators for recurrent UTI prevention
cranberry juice, capsules or tablets
topical estrogen in recurrent UTI prevention
mainstay of treatment in postmenopausal women with atophic vaginitis
adhesion blockers in recurrent UTI prevention
D-mannose
e. coli adhese to mannosylated receptors in the urothelium by means of FimH adhesion located on type 1 pili; theoretically blocked by D-mannose
antibiotic options in recurrent UTI prevention
self-start: have prescription at home just in case
suppressive
post-coital: low dose after sex, if sex is a risk factor
risk factors for recurrent UTI in postmenopausal women
low E incomplete bladder emptying incontinence prolapse diabetes
prevention of recurrent UTI in postmenopausal women
increase fluid intake
improve perineal hygiene
vaginal estrogen
characteristics of UTI during pregnancy
always considered COMPLICATED
17-20% of pregnancies
urine culture mandatory
when would you give a pregnant woman supressive abx
1 episode of pyelonephritis or 2 episodes of cystitis during pregnancy
give a low dose to reduce the risk of preterm labor
treatment of pyelonephritis in pregnancy
hospitalization and IV abx
asymptomatic bacteriuria in pregnancy
screen at inital prenatal visit
ALWAYS TREAT; reduced morbidity and complications
2-10% incidence
risks of asymptomatic bacteriuria in pregnancy
preterm rupture of membranes
preterm labor
chorioamnioitis
postpartum fever
acute pyelonephritis during pregnancy
increased risk during pregnancy maternal risks: septic shock resp and renal insufficiency fluid balance disorders death
what abx can you use during pregnancy
penicillin
cephalosporin
nitrofurantoin
fosfomycin
AVOID DURING PREGNANCY
fluoroquinolones: cartilage development issues
chloramphenicol: gray baby syndrome
trimethoprim: folate antagonism
erythromycin: maternal cholestatic jaundice
tetracyclines: fetal bones/teeth, maternal liver
prevalence of asymptomatic bacteriuria
2-5% of adult women 7-9% of diabetic women 25-50% of elderly institutionalized 50% SCI 100% chronic indwelling foley catheter
when is there and indication to screen for or treat asymptomatic bacteriuria
pregnant women
persons scheduled for GU instrumentation
staghorn calculus
renal stone comprising most of the collecting system
majority are struvite (magnesium ammonium phosphate)
lead to recurrent UTIs, urosepsis, renal functional deterioration
struvite stones
caused by bacteria that produce urease
-leads to a more alkaline pH which allows for rapid formation of struvite stones
urease producing bacteria
proteus enterobacter morganella serratia klebsiella
treatment of complicated UTI
urine culture MANDATORY
duration of treatment 7-14 days
broad spectrum abx and adjusted according to culture results
switch to oral therapy at 48 hrs after clinically well
abx options in complicated UTI
IV fluoro aminoglycosides +/- ampicillin 3rd generation cephalosporin extended spectrum penicillin carbapenem
