Author: Associate Prof Siow Woei Yun, Raffles Hospital

Fifty percent of women will suffer at least one urinary tract infection during their lifetimes. Some will experience recurrent urinary tract infections. Frequent urinary infections may result in long-term adverse consequences on the organs involved e.g. the bladder and the kidney.

Urinary tract infections more commonly affect the bladder than the kidney. This is because the entry of bacteria into the urinary system is usually via the urethra, in which case, the bladder is the first target of infection. Infection of the bladder is also known as “cystitis”.
Infection of the bladder and urethra results in bladder and urethral inflammation. The common symptoms of bladder and urethra infection include:

  • Increased urinary frequency
  • Pain over the bladder i.e. lower abdomen;
  • Pain during urination;
  • Blood stained urine (this occurs in more severe inflammation of the bladder)
  • Fever (this is associated with more severe infections).

If the infection is not treated timely, bacteria may ascend to the kidneys, in which case, there will be inflammation and pain over the kidneys i.e. loin pain. High, recurrent fever is also a typical feature of kidney infection. Kidney infection is a more serious form of urinary infection compared to bladder infection. The former is occasionally life-threatening particularly, in older people and immuno-compromised individuals.

Recurrent bladder infections may result in a state of chronic inflammation where the symptoms of bladder infection persist despite an absence of bacteria within the urine. Similarly, recurrent kidney infections may result in the development of kidney scars and in the long-term, impaired kidney function. Thus, the timely treatment of urinary tract infections is important. The prevention of recurrent urinary tract infections is even more important. This begins with a thorough evaluation of the urinary system to exclude abnormalities of structure and function. Specific risks contributing to recurrent infections include urinary stone disease, congenital abnormalities of the urinary system and abnormalities of urinary flow. These conditions need to be treated before recurrent urinary infections can be checked. Thereafter, various preventive strategies can be implemented to reduce the frequency of recurrent infections.

The short length of the female urethra and its opening in the vulval vestibule are both risk factors for urinary tract infections in females. Bacteria can easily “migrate” from the vagina into the bladder or from the external environment into the bladder, via the short urethra. Improper or inadequate hygiene can also transfer bacteria from the intestines into the bladder. Bacteria that is benign in its native environment may cause diseases when transferred to a new environment. Thus, urinary tract infections often result from bacteria that is native to the vagina and the intestines.

The most important preventive measure against urinary tract infection is adequate hydration. This ensures sufficient urine output to cleanse the urinary system. In general, the average size adult will require approximately 1.5 – 2 litres of fluid per day. Additional fluid that is lost through physical activities must also be replaced.

To avoid post-coital i.e. post-intercourse urinary tract infections, passing urine after sexual intercourse is advisable. Also, attention to personal hygiene is important to prevent the transfer of intestinal bacteria into the urinary system.

Cranberry and probiotic preparations are useful nutritional supplements to prevent recurrent urinary tract infections in susceptible populations.

Long term/regular antibiotic usage can prevent recurrent urinary tract infections, but this therapeutic modality is associated with potentially serious side effects and should only be used as a last resort and under the directions of a urinary tract specialist.