UTIs W3 Flashcards
name for infection of the upper urinary tract?
pyelonephritis
name for infection of the lower urinary tract?
cystitis
risk factors for uncomplicated UTIs?
females
previous UTIs
sexual activity
vaginal infection
diabetes
obesity
genetic
older age (oestrogen deficiency, cog impairment)
who gets complicated UTIs?
patients with factors that compromise the urinary tract or host defence:
-urinary obstruction (prolapse, enlargement)
-urinary retention caused by neuro disease
-immunosuppression
-renal failure
-renal transplantation
-pregnancy
-presence of foreign bodies (catheters etc)
post menopause and UTIs?
more susceptible due to vaginal dryness
why does urinary obstruction/retention cause UTIs
causes stagnant urine
features of gram positive organisms
thick cell walls
live in dry places (skin, muscular and soft tissue infections)
eg staph and strep
features of gram negative organisms
soft cell membrane
live in wetter places (gallbladder, urinary tract, gut)
eg e-coli
what type of organism causes UTIs? what is the most common cause?
UTIs are normally caused by gram negative organisms.
UPEC - uropathogenic E coli
UTI pathophysiology?
uropathogen from the gut contaminates periurethral area. urethra colonised, migrates and colonises bladder. neutrophil infiltration, bacterial multiplication and immune system subversion. biofilm formation, epithelial damage. ascension to and colonisation of the kidneys. bacteraemia (bacteria in blood)
how is the bladder cell wall invaded? what does this lead to?
type 1 pili. multiplication to form intracellular bacterial communities. these exfoliate or form quiescent bacterial reservoirs.
what may quiescent bacterial reservoirs cause and why
recurrent UTI as difficult to kill with antibiotics due to hibernating state.
bacteria virulence factors?
adherence - pili, adhesins
toxin production - eg haemolysins
immune evasion - eg capsule
iron acquisition
other - flagella
haemolysins?
break down haem to provide food for bacteria
antibacterial defences?
urine (low pH and high urea make it toxic for bacteria)
urine flow
urinary tract mucosa (bactericidal activity, cytokines)
urinary inhibitors of bacterial adherence (tamm-horsfall protein)
inflammatory response
types of UTI in males?
urethritis - urethra
prostatitis - prostate
epididymis-orchitis - epididymis
cystitis - bladder
pyelonephritis - kidneys
why is prostatitis difficult to treat?
only certain antibiotics can penetrate the prostate. usually needs a longer course of treatment.
clinical presentation of pyelonephritis?
loin pain/flank tenderness
fever/rigors
sepsis
clinical presentation of cystitis?
dysuria
frequency
urgency
suprapubic tenderness
clinical presentation of UTIs in infants?
vomiting, fever
clinical presentation of UTIs in elderly?
less localised symptoms. confusion/falls
dysuria?
painful urination
who should the dipstick be used for and why?
patients <65 only in presence of clinical UTI symptoms.
asymptomatic bacteria commonly present in elderly cause no harm and can play a role in preventing UTIs, but cause positive results on the dipstick.
types of bacteriuria definitions? - from urine culture results
significant bacteriuria: indicates number of bacteria in voided urine exceeds the number expected from contamination from the anterior urethra
asymptomatic bacteriuria: significant bacteriuria in a patient without symptoms (only ever treated in pregnant women)
symptomatic bacteriuria: UTI
antibiotics for cystitis?
trimethoprim: 200mg every 12 hours. 3 days for women, 7 days for men.
nitrofurantoin - 100mg every 12 hours. ONLY FOR CYSTITIS!!!
who is nitrofurantoin unsafe for?
patients with fever and loin pain.
antibiotics for cystitis negatives?
increases risk of recurrent UTI
increases antimicrobial resistance
antibiotics for pyelonephritis?
gentamicin. consider adding amoxicillin (vancomycin for penicillin allergy)
when is amoxicillin or vancomycin added to pyelonephritis treatment?
enterococcus isolated in urine in last 12 months or
source of infection is unclear or
patient has signs of severe sepsis
antibiotics for catheter associated UTI?
gentamicin
may only need single shot of gentamicin and a catheter change.
how are catheter associated UTIs diagnosed?
clinically!!!
don’t use dipstick or urine culture - will prob be positive regardless.
UTI management for men?
is prostate involved? - requires longer treatment and specific antibiotics
UTI management for pregnant women?
treat asymptomatic bacteria - reduces risk of pyelonephritis which can lead to pre-term labour
UTI management for children?
need investigation and consideration of vesico-ureteric reflux (reflux from bladder to ureter, common cause for dialysis)
advice for recurrent UTIs?
fluid intake 2-2.5L per day
avoid fizzy drinks, caffeine, alcohol
intercourse advice - lubrication, pre and post coital voiding, personal hygiene, positioning to reduce friction
STI screening
hygiene - wipe front to back
avoid perfumed products
treat constipation
consider weight reduction
stop smoking
