Normally, urine is sterile of germs. UTI is the abnormal situation in which germs manage to enter and multiply within the urinary tract, therefor creating this inflammation.
I would totally arbitrary and simplistic to divide the UTI here in two major categories as we see in everyday practice. Of course we must always take into account our view that every rule has its exceptions.
A. Urinary tract infection without fever
Urinary tract infections are confined to the bladder and lower urinary tract called better cystitis (bladder inflammation). Women and girls do very often cystitis because of anatomy. The urethra, the channel through which they urinate, is very short (1-2 cm) so the bladder is easily accessible by germs from outer space. The cystitis in women are far more often when they start their sexual life because the contact facilitates the entry of germs. The cystitis are combined relatively rare with congenital anatomical abnormalities but always must be a minimum check, at least by ultrasound. Urinary tract infections as cystitis are treated with an oral antibiotic treatment.
In some children who do recidivent cystitis we are obliged to give daily prophylactic antibiotic treatment in small doses for some time. Generally cystitis is not dangerous for the renal function.
B. Urinary tract infection with fever
The fever caused by urinary infection is almost always above the 38th Celsious. Here things get serious. Fever diles that germs have reached kidneys. The kidney is inflamed and because it is a filter through which passes the blood, the germs can pass into general circulation, so we have septicemia.
Such an infection is called pyelonephritis and it can leave behind the correct antibiotic treatment damage to the kidneys, the scars as usually described. In newborns and small children, pyelonephritis affects quickly their overall situation, particularly if combined with septicemia. Usually needs hospitalization and intravenous antibiotic treatment.
When a child makes pyelonephritis, needs to be done (after sterilized urine) a thorough examination with ultrasound, retrograde cystography, in search of the famous vesicorenal reflux and often renal scintigraphy, with measurement of renal function and renal scarring search. More rarely need other tests such as intravenus pyelogram, urodynamic testing, endoscopy etc.
This check will usually lead to the diagnosis of a congenital anatomical anomaly (vesicorenal reflux of obstraction of urine evacuation system). It is more rare to find a functional problem of the bladder or even nothing. If nothing is found, the child will immediately follow a six months prophylactic antibiotic treatment in low dose as we must believe that there is something that did not appear in the examinations.
Generally pyelophritis is dangerous for the renal function.
