The natural history of urinary tract infection in women.

Many women who suffer from the symptoms of urinary tract infection have a negative urine culture when conventional methods are used. Their condition is described as 'urethral' (or 'dysuria/frequency') syndrome' (US). As they may be indistinguishable clinically from those with positive cultures antibiotics are often prescribed. Their symptoms are usually recurrent and they may receive many courses of treatment. Some women are said to have 'interstitial cystitis' (IC); they have a long history of symptoms and antibacterial treatment. The urine contains white blood cells (pyuria) and biopsy of the bladder wall shows the histological changes of chronic inflammation. Additional culture techniques applied to urine from these two groups of patients consistently yield bacteria, most commonly lactobacilli in those with US. From the urine of women with IC, lactobacilli and some other 'fastidious' bacteria are isolated from catheter specimens and also from bladder wall biopsies. These bacteria are known to be constituents of the mixed commensal flora of the distal one-third of the urethra. It is proposed that these two syndromes are different stages in the natural history of UTI, and that antibacterial agents, by selection of resistant bacteria in the urethral commensal flora, are an important aetiological factor. It is possible that these bacteria may invade the paraurethral glands via their ducts - a situation analogous to invasion of the prostate in men. There is a considerable body of evidence supporting this hypothesis, but as it all emanates from one centre it needs to be confirmed elsewhere. Acceptance would bring great clinical benefit and considerable financial savings. A laboratory protocol which requires only small additional expenditure, and a clinical management regimen are proposed. At present, much antibacterial treatment is prescribed and many patients undergo radiological and invasive investigations such as cystoscopy and urethral dilatation, the latter incurring the risk of post-instrumentation UTI. There is evidence that 'US' responds gradually if antibiotics are withheld. 'IC' is a more difficult problem because bacteria may have invaded the bladder wall. Carefully targeted antibacterial treatment given for at least 10-14 days might be effective, but there are no data on this. Rational management of 'US' might prevent the development of 'IC'. A recent thorough review of published work on this condition states that the aetiology is still unknown. It appears, however, that no attempt has been made in any recent studies to use urine culture techniques capable of detecting bacteria other than the recognised aerobic pathogens.