William Aiken

Urinary tract infections (UTIs) are common among sexually active women and infrequent in men except when they are old.

One in every four women will experience aUTI at least once in her lifetime and, of those who do, the likelihood of having another UTI is high. Men, unlike women, experience UTIs rarely and when they do, it often signals that something is amiss with their urinary tract.

Anatomical differences between men and women largely account for the difference in incidence of UTIs. The female urethra extends from the neck of the bladder to the opening on the vulva, and lies in the front wall of the vagina. Its opening is in front of the entrance to the vagina, while the vagina itself lies in front of the rectum.

As a consequence of the close proximity between the anus and the vaginal entrance, germs originating in the rectum may readily spread to the vagina and multiply in it. The multiplication of germs is inhibited by the presence of healthy bacteria in the vagina which keep its secretions normally acidic.

Cranberry juice

During vigorous sexual activity the female urethra may be bruised and bacteria present at its opening may be pumped up the urethra. Bruising of the urethra reduces its resistance to infection which facilitates the ascent of germs up the urethra thereby allowing them access to the bladder.

Once in the bladder, the bacteria adhere to the lining of the cells and rapidly multiply. Bacterial adherence may be facilitated by the presence of certain receptor molecules on the bladder cell wall which are especially present in some women possessing certain blood groups. Bacterial adherence and infection may be inhibited by molecules present in cranberry juice.

Burning or pain

Symptoms of a bladder infection are similar in men and women and include frequent passage of small volumes of urine, burning or pain on passing urine, inability to 'hold' the urine, lower abdominal pain, passing cloudy and/or offensive urine, and on occasions blood may be present in the urine.

Urinary tract infections in men mostly occur whenever there is some obstruction to the free flow of urine such that there is incomplete emptying of the bladder after urination, which results in stagnation of urine. Urinary tract infections also occur when there is persistence of bacteria in the urinary tract due to their adherence to substances such as stones or scar tissue abnormally present in the urinary tract.

Sexually active women who suffer from recurrent post-coital urinary tract infections ('honeymoon cystitis') can minimise this by showering before sex, avoiding the use of spermicidal jelly and the diaphragm, passing urine immediately after sex, maintaining a high fluid intake, and passing urine every three to four hours regardless of whether there is an urge to urinate.

Wiping from front to back is recommended and drinking cranberry juice may be helpful. If these measures do not resolve the problem, then a single pill of an appropriate antibiotic can be taken after sex, for a period of at least six months.

Diabetes increases risk

Since UTIs in men usually signal an underlying problem, in addition to treating the UTIs, full investigation is required to determine their cause so treatment can be specifically directed to it.

Common causes include an enlarged prostate, chronic bacterial infection of the prostate, urethral strictures or narrowing, a tight foreskin and bladder stones. The presence of a foreign body such as a urethral catheter used to relieve retention of urine significantly increases the risk of a UTI over time. General conditions which reduce immunity such as diabetes mellitus also increase the risk of UTIs.