Urinary tract infection (UTI)

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Urinary tract infection (UTI) is the presence of micro-organisms in the urine or tissues of the normally sterile genitourinary tract.

Infection may be localized to the bladder alone or the kidneys or, in men the prostate.

Acute uncomplicated UTI occurs in women with a normal genitourinary tract and usually manifests as acute cystitis (bladder infection or lower tract infection).

Complicated UTI occurs in individuals with structural or functional abnormalities of the genitourinary tract, including those with indwelling devices such as urethral catheters.

Congenital abnormalities of the genito-urinary tract predispose children to UTI. Proven UTI in a child or recurrent UTI requires further urogenital evaluation.

Definitive treatment of UTI depends on culture and sensitivity reports. However, empirical treatment may be initiated while awaiting the report.

Causes of Urinary Tract Infection

The causes of UTI include the following:

  1. Bacteraemia or septicaemia
  2. Urinary tract obstruction e.g. enlarged prostate in adult males, posterior urethral valves in infants/children

Symptoms of Urinary Tract Infection

The following are the symptoms of UTI

  1. Frequent painful urination
  2. Haematuria
  3. Cloudy/foul smelling urine
  4. Vomiting
  5. Suprapubic pain
  6. Fever – may be persistent and unexplained (in children)
  7. There may be feeding problems, diarrhoea, and failure to thrive as well (in children)

Note

UTI symptoms can be non-specific in young children.

Signs of Urinary Tract Infection

Signs of UTI include the following:

  1. Fever
  2. Loin tenderness
  3. Suprapubic tenderness
  4. Foul smelling urine

Investigations

  • FBC
  • Mid-stream specimen of urine for microscopy, culture and sensitivity (re-culture urine after treatment)
  • Abdominal ultrasound scan in children if indicated

Treatment for Urinary Tract Infection

Treatment objectives

  1. To relieve symptoms such as fever and pain (See ‘Fever‘ and ‘Pain Management’)
  2. To eradicate causative agent
  3. To prevent complications
  4. To identify patients with abnormalities of the genito-urinary tract
  5. To improve the quality of life of patients with UTI

Non pharmacological treatment

  • Liberal oral fluids to encourage good urinary output
  • Personal hygiene and proper cleaning after defaecation

Pharmacological treatment

A. Treatment of Uncomplicated UTI

1st Line Treatment

Evidence Rating: [C]

Ciprofloxacin, oral,

Adults: 500 mg 12 hourly for 7 days (female); 10-14 days (male)

Children: 15-20 mg/kg 12 hourly; (max. of 750 mg daily in two divided doses)

Or

Cefuroxime, oral,

Adults: 250-500 mg 12 hourly for 5-7 days (female); 10-14 days (male)

Children:

  • 12-18 years; 250 mg 12 hourly for 5-7 days
  • 2-12 years; 15 mg/kg 12 hourly (max. 250 mg) for 5-7 days
  • 3 months-2 years; 10 mg/kg 12 hourly (max. 125 mg) for 5-7 days

B. Treatment of Complicated UTI (including catheter-related, stones, prostate enlargement, urologic abnormalities and pregnancy)

1st Line Treatment

Evidence Rating: [C]

Ciprofloxacin, IV,

Adults: 400 mg 8-12 hourly for 7 days (to be administered over 60 minutes)

Or

Gentamicin, IV, (if kidney function is normal)

Adults: 40-80 mg 8 hourly for 7 days

Children:

  • 12-18 years; 2 mg/kg 8 hourly for 7 days
  • 1 month-12 years; 2.5 mg/kg 8 hourly for 7 days

Or

Ceftriaxone, IV,

Adults: 1-2 g daily for 7 days

Children: All ages 25 mg/kg 12 hourly (max. 75 mg/kg daily)

Or

Amoxicillin + Clavulanic Acid, IV,

Children:

  • 1 month-18 years; 20-30 mg/kg 8 hourly (max. 500 mg) for 5 – 7 days
  • Neonates (dose doubled in severe infection)
    • 7-28 days; 30 mg/kg 8 hourly for 5-7days
    • < 7 days; 30 mg/kg 12 hourly for 5-7days

And

Gentamicin, IV, (slow intravenous injection over at least 3 minutes)

Children:

  • 12-18 years; 2 mg/kg 8 hourly
  • 1 month-12 years; 2.5 mg/kg 8 hourly

Or

Cefuroxime, IV,

Children:

  • 1 month-18 years; 20 mg/kg 8 hourly max. 750 mg, (increase to 40-50 mg/kg max. 1.5g 6-8 hourly in severe infections)
  • Neonates (double the dose in severe infections, IV route only)
    • 21-28 days; 25 mg/kg 6 hourly
    • 7-12 days; 25 mg/kg 8 hourly
    • < 7 days; 25 mg/kg 12 hourly

Referral Criteria

Refer patients who are very ill, with recurrent UTI, persistent haematuria and congenital abnormalities to the appropriate specialist.

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