Urinary tract infection Flashcards
What is cystitis?
inflammation of the bladder
Why are UTIs more common in women?
shorter urethra
What bacteria is the most common cause of UTIs?
E. coli
Other than E. coli, name 5 causative bacteria of UTIs:
1) Pseudomonas species
2) Staphylococcus saprophyticus or epidermidis
3) Enterococcus faecalis
4) Klebsella
5) Proteus species
Give 4 virulence factors that determine a bacteria’s potential to cause UTIs:
1) presence of a flagella (motility)
2) aerobactin (obtains iron)
3) haemolysin (forms pores in urothelium)
4) fimbriae (adhesins that attach organisms to the perineum and urothelium)
Give 7 key risk factors for UTIs:
1) female sex (particularly in post-menopausal women)
2) new sexual activity
3) indwelling urinary catheter
4) urinary tract stones
5) urinary tract stasis (due to incomplete bladder emptying)
6) diabetes
7) immunosuppression
Give 8 symptoms of UTIs:
1) frequency
2) dysuria
3) incontinence
4) suprapubic pain and tenderness
5) haematuria
6) smelly urine
7) confusion (in elderly patients)
8) nocturia
Name 6 symptoms that when coupled with typical UTI symptoms, suggests pyelonephritis:
- Loin pain
- Tenderness
- Fevers
- Chills
- night sweats
- Rigors
Give the diagnostic criteria for uncomplicated UTIs:
they can be diagnosed if a patient exhibits at least two of the three cardinal symptoms
1) dysuria
2) urgency
3) frequency
(neither urine dipstick or urine culture enhances diagnostic sensitivity)
What two urinalysis findings suggest UTI?
1) pyuria (presence of raised white cells or pus)
2) nitrates
True or false: nitrates without raised WCs in urine still indicates UTI
true
True or false: raised WCs without raised nitrates in urine still indicates UTI
False
Why are raised nitrates associated with UTIs?
nitrates are formed by gram-negative organisms as they reduce nitrates to nitrites
Define UTI relapse:
recurrence of bacteriuria with the same organism within 7 days of completion of antibiotics
What does UTI relapse indicate?
may suggest associated stones, scarred kidneys, polycystic disease, bacterial prostatitis or any other complication
Define UTI re-infection:
when bacteriuria is absent after treatment for at least 14 days followed by recurrence with the same OR different organism
What lab test should follow positive urinalysis findings?
Urine culture
Name three conditions with UTI-like symptoms but negative urine culture:
1) interstitial cystitis
2) urethral syndrome
3) irritable bladder/ predominant frequency
What is interstitial cystitis?
An autoimmune bladder disease with UTI symptoms
Give 4 causes of urethral syndrome:
1) bladder trauma
2) vaginitis
3) Chlamydia
4) TB
What is urethral syndrome?
Symptoms of UTI without any demonstrable infection
What scan is used to investigate complicated UTIs?
urography
How many days should antibiotics for a simple urinary tract infection be taken for?
3 days
How long should antibiotics for UTI patients with immunosuppression, abnormal anatomy or impaired kidney function be taken for?
5-10 days
How long should male, pregnant or catheter-related UTI patients take antibiotics for?
7 days
What are the two first line antibiotics for UTIs and pyelonephritis?
1) trimethoprim
2) nitrofurantoin
Name three antibiotics that can be used to treat UTIs and pyelonephritis when trimethoprim and nitrofurantoin are contraindicated?
1) pivmecillinam
2) amoxicillin
3) cefalexin
When is trimethoprim contraindicated?
pregnancy (particularly in the first trimester due to folate antagonism)
When is nitrofurantoin contraindicated?
third trimester of pregnancy (linked to haemolytic anaemia in the new born)
What is chronic pyelonephritis/ reflux nephropathy?
where the one-way vesicoureteric junction allows back flow of urine into the bladder leading to incomplete bladder emptying and predisposing to infection
Give 3 features seen on a CT scan of a kidney with reflux nephropathy/ chronic pyelonephrititis:
- Irregular renal outlines
- Clubbed calyces
- reduction in renal sizes
Name 5 conditions with similar clinical presentations to pyelonephritis:
1) pelvic inflammatory disease
2) pelvic pain syndrome
3) cystitis
4) acute prostatitis
5) lower lobe pneumonias
Name 5 lifestyle changes that can be used to reduce risk of recurrent UTIs/ pyelonephritis:
1) 2L daily fluid intake
2) voiding at 2-3 hour intervals
3) voiding before bedtime and after intercourse
4) avoidance of chemicals around the urethra e.g. bubble baths and spermicidal jellies
5) avoidance of constipation (this can impair bladder emptying)
What is pelvic inflammatory disease?
infection of pelvic organs caused by infection spread through the cervix
What is the name of the uncommon kidney infection characterised by interstitial damage caused by Proteus bacteria?
xanthogranulomatous pyelonephritis
Give 4 symptoms of xanthogranulomatous pyelonephritis:
1) palpable enlarged kidney(s)
2) weight loss
3) fever
4) loin pain
What two pathologies are xanthogranulomatous pyelonephritis cases typically seen alongisde?
1) staghorn calculi
2) UTIs
Give a sign of xanthogranulomatous pyelonephritis on CT:
intrarenal abscesses
What is the treatment for xanthogranulomatous pyelonephritis?
nephrectomy (antibiotics rarely work)
