Urinary Tract Infections Flashcards
inflammation of upper urinary tract is called
pylenephritis
inflammation of lower urinary tract is called
cystitis
risk factors for uncomplicated UTIs
females
those with previous UTIs
sexual activity
vaginal infection
diabetes
obesity
genetic susceptibility
older age
why are diabetics more susceptible to UTIs
sugar in urine which good for bug growth
who is at risk of complicated UTIs
those with compromised urinary tract or host defence such as
urinary obstruction
urinary retention
immunosuppression
renal failure
renal transplant
pregnancy
presence of foreign bodies
antibiotic exposure
indwelling catheters
what is the most common cause of secondary bloodstream infection
complicated UTI
most common organism to cause UTI
uropathogenic e.coli (UPEC)
why is kidney infection likely to lead to blood infection
kidneys are very vascular
steps of UTI infection
- contamination of the periurethral area with uropathogen from the gut
- colonisation of the urethea and migration to the bladder
3a. colonisation and invasion of the bladder. mediated by pili and adhesins
3b. inflammatory response in the bladder and fibrinogen accumulation in the catheter - neutrophil infiltration
- bacterial multiplication and immune system subversion
- biofilm formation
- epithelial damage by bacterial toxins and proteases
- ascension to the kidneys
- colonisation of the kidneys
- host tissue damage by bacterial toxins
- bacteraemia
what are the bacterial virulence factors
adherence - pili and adhesins
toxin production
immune evasion
iron aquisition
other - e.g. flagella
why do bacteria require pili and adhesins to colonise a bladder
to resist flushing out when someone urinates
what host defences do humans have to avoid
low pH of urine
high urea conc. of urine
urine flow and micturition
urinary tract mucosa
urinary inhibitors of bacterial adherence
inflammatory response
where do pathogens come from to cause UTIs
uropathogen from gut
intracellular bacterial communities/quiescent intracellular reseviors
haematogenous - rrare
where can the infection go from a UTI
bacteraemia
perinephric abscesses
remote deep seated infection (e.g. spinal) - rare
presentation of pyelonephritis
loin pain/flank tenderness
fever/rigors
sepsis
presentatio of cystitis
dysuria
frequency
urgency
suprapubic tendernesa
what is dysuria
pain or burning sensation when urinating
when is dipstick useful
in <65s
in presence of clinical UTI symptoms
what % of older people have bacteria in urine which is not harmful
50%
100% if long term urinary catheter
when is asymptomatic bacteriuria treated
in pregnancy
what type of bacturia is a UTI
symptomatic
(signifcant but asymptomatic isn’t)
purpose of Abx in cystitis
improving and shortening symptom duration
how does UTI treatment differ if the prostate is involved
longer treatment required and specfic Abx to penetrate prostate
what needs to be consider in children with UTI
vesicoureteric reflux
needs corrected to avoid need for dialysis
risk factors for recurrent UTI
women
antibiotic use
