Suspect lower UTI

• Suspect lower urinary tract infection (UTI) if the man has:
• Symptoms of UTI: dysuria (painful urination), frequency, urgency (the desire to pass urine immediately), nocturia (having to urinate during the night more frequently than usual), and suprapubic discomfort — these symptoms are usually present.
• Signs of UTI: suprapubic tenderness, and cloudy, bloody, or foul-smelling urine — although typical of UTI, these signs may be absent.
• Diagnosis can be difficult in men who are frail and elderly, or institutionalized, or who have an indwelling urinary catheter. UTI can present with atypical symptoms, and bacteriuria can be present when there are no specific urinary symptoms and signs. Therefore, considerable clinical judgement is required in this situation. Suspect UTI if any of the following are present:
• Change in urinary symptoms, for example urine becoming very smelly, cloudy, or bloody.
• Suprapubic or urethral discomfort.
• Feeling generally unwell.
• Fever.
• Increased confusion or new onset of confusion.

Exclude other causes

• If the man also has fever or loin pain (or both), suspect and manage as upper UTI — see the CKS topic on Pyelonephritis - acute.
• Consider other possible causes for the symptoms, in particular urethritis.

Confirm the diagnosis

• Confirm the diagnosis with a urine culture.
• Because empirical treatment will usually need to be started immediately, it is important to obtain a urine sample for culture before starting treatment.
• Do not rely on urine dipstick tests or microscopy to confirm the diagnosis.
• When symptoms are moderate or severe, or suggestive of UTI, neither dipstick tests nor microscopy can reliably confirm or exclude the diagnosis of UTI.
• If the man has mild or non-specific symptoms of UTI, a negative urine dipstick test (both nitrite and leukocyte esterase tests negative) can safely exclude UTI.

[SIGN, 2006; European Association of Urology, 2009]