Usually describes acute urethritis and cystitis caused by a microorganism.
Background/Epidemiology
- Common- accounts for around 1-3% of consultations in GP; affects around 3% of women at age 20 and increasing by ~1% every decade.
- In men, UTI is uncommon except in neonates/infants and in men >60 with LUTS.
Risk
- More common in women because, the urethra is shorter and there is closer proximity between the urethra and the vagina and anus.
- Patients with catheters (or other instrumentation or foreign bodies- technically including renal stones) are also much higher risk
- Bladder outflow obstruction e.g. BPH, Prostate Cancer, urethral stricture
- Uterine prolapse
- Neurological conditions e.g. MS, diabetic neuropathy
- Diabetes mellitus
- NB Have a high clinical suspicion in elderly people (particularly females) who have acute onset fever or delirium of unknown cause, as this is the most common cause.
Pathophysiology
- The most common organisms to cause UTIs are
- E coli (from the GI tract- account for ~75%)
- Proteus spp
- Staphylococcus saprophyticus
- Other organisms include
- Pseudomonas spp, streptococci and staph epidermidis
- In hospital, Klebsiella and streptococci are more common (E coli still most common)
- Entry of the organisms may be retrograde (via the urethra), via the bloodstream (particularly in immunosuppressed) or direct (via instrumentation)
Clinical Presentation
- abrupt onset frequency and urgency of micturition
- scalding/burning pain (dysuria) in the urethra during micturition
- suprapubic pain during and after voiding
- feeling of incomplete emptying (due to spasm of the inflamed bladder wall)
- cloudy urine which may have an offensive smell
- there may also be haematuria
- Systemic symptoms e.g. fever, rigors, nausea/vomiting, confusion etc are usually only mild in simple UTI. If these signs are present, suspect pyelonephritis and/or bacteraemia.
- Make sure to ask about previous UTIs and PMHx
Investigations
- NB UTI in females is a clinical diagnosis and investigations aren’t completely necessary. UTI in males should be investigated with culture (male UTI is often immediately classed as complicated)
- Urinalysis
- Leucocytes and nitrites are suggestive of UTI
- Urine microscopy/culture & sensitivity
- In some cases, particularly if the patient is having recurrent episodes or if there is a history suspicious of renal stones, USS imaging may be of benefit.
Management
- In uncatheterised patients
- 1st line- Trimethoprim 200mg BD for 3 days (female- unless pregnancy is suspected/known) or 7 days (male) OR Nitrofurantoin MR 100mg BD or 50mg QDS for 3 or 7 days.
- 2nd line- culture sample and treat as sensitivities
Special cases
- Patients with chronic kidney disease
- In patients with CKD 3B/4/5, consider pivmecillinam (400mg stat then 200mg TDS for 3 days)
- UTI in pregnancy
- 1st line nitrofurantoin MR 100mg BD or 50mg QDS for 7 days in the 1st and 2nd trimester
- In the 3rd trimester, trimethoprim 200mg BD for 7 days
- 2nd line cefalexin 500mg every 8 hours for a minimum of 7 days or as per sensitivities
- 1st line nitrofurantoin MR 100mg BD or 50mg QDS for 7 days in the 1st and 2nd trimester
- Recurrent UTIs in women (≥2/month or ≥3/year)
- Treat for 6 months then review
- 100mg trimethoprim at night/post-coital OR nitrofurantoin 50-100mg at night/post-coital
- (Cranberry juice/extract also has evidence)
- Catheterised patients
- In the presence of a catheter, antibiotics will NOT eradicate bacteria
- Change catheter prior to treatment
- Send sample
- Treat only if symptomatic/systemically unwell
- If in the community
- Co-amoxiclav 625mg TDS for 14 days or cotrimoxazole 960mg BD for 14 days
- 2nd line, base on sensitivities
- Co-amoxiclav 625mg TDS for 14 days or cotrimoxazole 960mg BD for 14 days
- If in hospital
- IV Amoxicillin and Gentamicin (cotrimoxazole + gentamicin)
- Aztreonam can be used as an alternative to gentamicin in patients with kidney failure (AKI/CKD)
- Step down to co-trimoxazole or adjust as sensitivities suggest for 14 days total
- IV Amoxicillin and Gentamicin (cotrimoxazole + gentamicin)