What investigations are necessary for a patient with a suspected UTI who presents with atypical symptoms or is systemically unwell?

For a patient with suspected urinary tract infection (UTI) who presents with atypical symptoms or is systemically unwell, the following investigations are necessary:

• Urine sample for culture and sensitivity testing should be sent before starting antibiotic treatment to identify the causative organism and guide antibiotic choice, especially if symptoms are severe, atypical, or there is risk of complications ¹.
• Blood tests may be indicated if systemic illness or sepsis is suspected, to assess for complications such as pyelonephritis or sepsis ¹.
• Imaging studies such as urinary tract ultrasound should be performed during the acute infection in patients with atypical UTI to identify structural abnormalities, obstruction, or other complications ².
• In children or infants with atypical UTI or systemic illness, consider power Doppler ultrasound or DMSA scintigraphy scan if upper UTI or renal involvement is suspected and diagnosis is unclear ².
• For patients with catheter-associated UTI and systemic symptoms, ensure a catheter urine sample is sent for culture and susceptibility testing, and consider catheter replacement if indwelling for 7 days or more ¹.
• Urgent hospital admission and specialist referral should be arranged if there are severe systemic symptoms or signs of life-threatening complications ¹.

These investigations help confirm diagnosis, identify complications, and guide appropriate management in patients with atypical or severe presentations of UTI.