Urinary tract infection in children: a review of its pathogenesis and risk factors.

Urinary tract infection (UTI) is one of the commonest bacterial infections seen in children, ranking second only to those of the respiratory tract. A steady flow of urine, complete emptying of the bladder and various host defences provide the principal means of protection. Urinary stasis, on the other hand, provides an opportunistic environment for bacterial multiplication; several other factors also contribute to UTI, such as urinary obstruction, vesico-ureteric reflux (VUR) and other urinary tract malformations. UTI, especially in the presence of VUR, may lead to scarring of the kidney and progressive renal disease. It is vital, therefore, to diagnose such anomalies at an early stage, the overall aim being to identify those at high risk so that measures may be taken to prevent serious complications and preserve renal function. Those at low risk of UTI, however, should not be over investigated; this is in order to keep invasive procedures down to a minimum. Whenever possible, the management of high risk cases is best discussed between paediatrician, microbiologist, radiologist, urologist and the general practitioner.