URINARY TRACT INFECTIONS (UTIs)

A UTI is an infection of any part of the urinary tract, i.e.

• Kidneys and ureters (upper urinary tract)
• Bladder and urethra (lower urinary tract).

Urine is normally sterile (but asymptomatic bacteriuria is present in 20% of women) and most UTIs arise from E. coli, which normally lives in the colon. UTIs are:

• More common (50x) in women than men
• Less common in men, but potentially more serious
• More common in the elderly

And can be classified as:

• Uncomplicated (normal urinary tract and function)
• Complicated (abnormal tract, male sex, impaired renal function, virulent organism, impaired host defences).

The sites of infection are:

• Urethra (urethritis): see also stis in Sexual health
• Bladder (cystitis)
• Kidney (pyelonephritis)

UTI symptoms and signs

Lower UTI (cystitis, urethritis) can present with dysuria, frequency, urgency, haematuria. The urine can be cloudy with an offensive odour. In older people, there may be generalised symptoms such as confusion and incontinence.

Upper UTI symptoms (pyelonephritis) as for lower UTI symptoms plus suprapubic pain or tenderness, pyrexia and possible rigors. The patient is likely to be ill and might require hospital admission.

Prostatitis may present with low backache, flu-like symptoms, urinary symptoms, swollen tender prostate. Diagnosis may require collection of a mid-stream urine specimen (MSU). Vigilance necessary in children, the elderly and pregnant women. A UTI in a pregnant woman is more likely to spread to the kidneys.

Infants and children

Consider UTI in any sick child, and every young child with unexplained fever. Infants under 3 months of age, presenting with failure to thrive and/or fever (38°C) and/or vomiting and/or irritability should have a urine sample tested for culture and sensitivities, and should be referred urgently for assessment. Children aged 3 months to 3 years with specific or non-specific urinary symptoms should have a urine sample tested for culture and sensitivities. In children aged 3 years and over, dip urine for leucocytes and nitrites. If both are positive, UTI is probably and treat accordingly. If both are negative, UTI is unlikely – explore other causes of illness. If one is positive, and one negative, send urine for culture, explore other causes and treat only if clinically likely to be UTI.

Advice to help prevent recurrent cystitis in women

• Increase fluid intake
• Urinate frequently; don't resist the urge to urinate
• Double void, i.e. pass urine again after 5-10 min.
• Void after intercourse
• Wipe from front to back

Factors increasing risk of UTI

• Catheters: a common source of infection.
• Diabetes (and any disorder that suppresses the immune system).
• Poor bladder emptying, prostatic enlargement in men, bladder or kidney stones, pregnancy.
• Incontinence associated with stroke or dementia.

Men

Referral for urological assessment is not routinely required for men unless they

• Have failed to respond to appropriate antibiotic treatment
• May have an underlying cause e.g. urinary obstruction
• Have a history of pyelonephritis, calculi or previous genitourinary tract surgery
• Are younger than 50 and have persistent microscopic haematuria with otherwise normal renal function tests