Urinary Tract Infections
Urinary tract infections are common, affect all age groups, and account for a significant proportion of all primary care visits. Urinary tract infections often affect sexually active women, and are relatively less frequent in men and in children.
Even though the urinary tract is usually very resistant to bacterial colonization, urinary tract infections are the most common bacterial infections in all age groups and, if overlooked and left untreated, may complicate to kidney damage. Urinary tract infections are almost always caused by intestinal bacteria, which reach the urinary bladder through the urethra, and are often sensitive to commonly used antibiotics.
Urinary tract infections can be separated into two categories:
• “lower” urinary tract infections, when they affect the urinary bladder (cystitis) or the urethra (urethritis)
• “upper” urinary tract infections (pyelonephritis), when they affect the kidneys and the renal pelvis.
It must be remembered, however, that the organisms responsible for cystitis, if not properly and promptly treated, may ascend to the upper urinary tract leading to pyelonephritis, an infection more difficult to treat. In practice, “upper” urinary tract infections are prognostically more serious than lower infections because of the potential risk of permanent consequences to the kidneys or ureters.
When symptoms related to a urinary tract infection develop, such as difficulty or burning on urination, it should be first established whether the symptoms have a urinary origin or whether they are a manifestation of functional disorders such as sexual or psychological problems. The reference standard for diagnosing urinary tract infections is the urine culture, since the type and number of organisms in the urine are the most useful indicators of urinary tract infection. The goals of antibiotic treatment in urinary tract infections are eradication of the infecting organism, prevention or control of bacteraemia and subsequent systemic complications, and avoidance of recurrent symptomatic urinary tract infections. Other important aspects to be considered in treatment decisions are the cost-benefit ratio and the need to avoid adverse effects. Another useful criterion for an appropriate therapy is the adequacy of the dose administered, not only in terms of quantity
but also in terms of time
, i.e. the interval between doses and the total duration of the therapy.