Lower urinary Infection and cystitis

Infection of the bladder gives rise to symptoms of frequency, urgency, suprapubic discomfort, dysuria and cloudy offensive urine. These symptoms are often known as ‘cystitis’. Lower urinary tract infections (UTI) are much more common in women than in men, particularly in the under 50s. Recurrent lower urinary infection occurs in some healthy women after intercourse, without any demonstrable abnormality of the urinary tract. Repeated attacks of UTI in women, or a single attack in a man or a child of either sex, should always be followed by investigation to discover and treat the predisposing cause; sometimes, however, no cause can be found. Asymptomatic bacteriuria is found commonly (in approximately 5—10 per cent of cases), particularly in women, and investigation may fail to demonstrate any underlying cause.

Predisposing causes

 Incomplete emptying of the bladder which may be secondary to bladder outflow obstruction caused by prostatic obstruction, urethral stricture or meatal stenosis, bladder diverticulum, neurogenic bladder dysfunction or decompensation of the detrusor muscle.

  The presence of a calculus, foreign body or neoplasm.

   Incomplete emptying of the upper tract caused by dilatation of the ureters associated with pregnancy or vesico ureteric reflux. In childhood, the mainstay of treatment of vesicoureteric reflux is antibiotic therapy; operation is reserved for those with recurrent infection despite antibiotics or severe upper tract dilatation.

  Oestrogen deficiency which may give rise to lowered local resistance.

   Colonisation of the perineal skin by strains of Escherichia coli expressing molecules that facilitate adherence to mucosa.

Avenues of infection

Ascending infection from the urethra is the commonest route (see Chapter 66). The organisms originate in the bowel, contaminate the vulva and reach the bladder because of the shortness of the female urethra. The passage of urethral instruments may cause urinary infection in either sex, especially when the bladder contains residual urine. This happens because it carries organisms from the urethra into the bladder (Fig. 65.40).

Other routes are less common. These include: descending from the kidney (tuberculosis), haematogenous spread, lymphogenous and from adjoining structures (fallopian tube, vagina or gut).

Bacteriology

Escherichia coli is the commonest organism, followed by Proteus mirabilis, Staphylococcus epidermidis and Streptococcus faecalis. Infection with other organisms or mixed organisms is found in patient with neurogenic bladder dysfunction or those with a long-standing indwelling urethral catheter. These organisms include Pseudomonas, Klebsiellae, Staphylococcus aureus and various streptococci. Tuberculous infection is considered below. The presence of pus cells without organism calls for repeated examination for Mycobacterium tuberculosis and Neisseria gonorrhoeae. Having eliminated these possibilities, the underlying condition may be abacterial cystitis, carcinoma in situ, renal papillary necrosis, stones or incomplete treatment of a urinary infection.

Clinical features

 Symptoms

The severity of the symptoms varies greatly.

Frequency. This occurs during the day and night, it may occur every few minutes and may cause incontinence.

Pain. Pain varies from mild to severe. It may be referred to the suprapubic region, the tip of the penis, the labia majora or the perineum.

Haematuria. The passage of a few drops of blood-stained urine or blood-stained debris at the end of micturition is a frequent accompaniment. Less often the whole specimen is blood stained.

Pyuria. This is usually present.

Examination

On examination there is tenderness over the bladder. Initial and midstream urine specimens should be collected in a male as acute prostatitis may be present (see below) which will lead to threads in the initial specimen. The midstream specimen must be subjected to microscopy and culture, and the sensitivity of any organisms assessed.

Treatment

Treatment should be commenced forthwith, and modified if necessary when the bacteriological report is to hand. The patient is urged to drink. Appropriate first-line antibiotics include trimethoprim, amoxycillin or one of the quinolones. Failure to respond indicates the necessity for further investigation to exclude predisposing factors.

Investigation

Cystoscopy. This is not necessary in the acute phase.

Other investigations. These include measurement of urinary flow rates and post-void residual urine. An IVU will usually be carried out together with cystoscopy. Difficult cases may require urodynamic investigation.