Urinary Tract Infection

Dr Victor Grech MD MRCP PhD

The urinary tract produces and stores urine which is then voided. This tract is made up of the kidneys which actually form urine and the ureters, two narrow tubes that pass urine down to the bladder for storage, and the urethra which voids urine.

Urinary tract infection (UTI) is a common infection in childhood. Urine does not contain bacteria (germs) unless it is infected. Infection can reach the urinary tract from the skin around the rectum and genitals and through the bloodstream from any other infected part of the body. Various sites of the urinary tract may become infected in isolation or in combination, and these parts include:

the kidneys

(causing ‘pyelonephritis’)

the bladder

(causing ‘cystitis’)

the urethra

(causing ‘urethritis’)

UTI affects up to 2% of school aged children and is commoner in girls, in individuals that are immunosuppressed (e.g. chemotherapy treatment for cancer) and in association with congenital malformations of the urinary tract. Uncircumcised boys have slightly more UTIs than those who have been circumcised.

Signs of a UTI may be unremarkable, especially in infants, and may therefore remain untreated with potentially serious health problems. Infants may only have fever, or may have vomiting or diarrhoea mimicking gastroenteritis. Older children will complain of pain on passing urine, or tummy pain or may need to urinate frequently, similar to adult symptoms of urinary tract infection.

The diagnosis of UTI is extremely important because of the potential catastrophic complications that may arise in later life:

UTI may lead to renal damage that may cause high blood pressure, that if undetected and untreated, may lead to progressive kidney disease with renal failure requiring dialysis and renal transplantation.

The risk of high blood pressure after renal damage is estimated at 10-20%. It is therefore crucial to confirm the diagnosis of UTI, because a firm diagnosis will necessitate tests looking for established renal damage or risk factors that may result in the future development of such damage if UTI recurs. These tests include both ultrasound and special x-rays.

The diagnosis can only be established by the collection of urine that is sent to the laboratory to check for bacterial growth, i.e. evidence of UTI. Urine must be collected prior to the administration of antibiotics. Urine may be collected via a variety of ways – the attending doctor will explain. Antibiotics may be started after urine collection, before a result becomes available, especially if a UTI is strongly suspected.

In conclusion, it is crucial to accurately diagnose UTI in childhood due to the potential long-term complications. It is equally important to be certain of UTI as the imaging investigations are extensive and invasive.

July 2004