Medihub - Medical Information - Urology

Normal urine is sterile. When bacteria get into the urine via the urethra, it can infect the bladder to cause cystitis [Fig 1]. Left untreated, the infection goes up to the kidneys to cause a more severe infection.

Urine infection is common and can affect children and adults alike. The symptom ranges from frequency of urination, lower abdominal pain, burning sensation in the urine passage, cloudy and smelling urine to frank blood in the urine. When the infection affects the kidneys, the patient can be very ill with loin pain, shivering and even shock.

Fig 1. Cystitis of the bladder showing inflamed lining

Causes
Urine infection more likely to occur when there is an abnormality in the urinary tract. Women are also more prone to urine infection because their urethra is much shorter and sexual intercourse predisposes to this urine infection.

Typically, young girls get their first cystitis when they become sexually active. Diabetic patients are also more likely to get urine infections due to the excess sugar in the urine. Women are also prone to urine infection after menopause because the state of the vagina and urethra becomes less healthy and more easily prone to infection.

Infections are also more likely to occur when there is stagnant urine in the bladder because of obstruction of bladder outlet eg. urethral stricture associated with menopause, bladder or urethral diverticulum, prostate enlargement in men or weak bladder function due to disease affecting the nerves to the bladder.

Ultimately the types of bacteria that get into the bladder originate from the faeces and maintaining local hygiene is an important way to prevent urine infection.

When the infection proves difficult to treat, an underlying cause should be suspected. This can range from a urinary obstruction, a nervous system disorder, a congenital anomaly of the urinary system, or urinary stones.

Symptoms
Urine infection can be suspected based on a typical history of an acute onset of frequent urination, burning pain, lower abdominal pain, back pain and cloudy or bloody urine.

Diagnosis
1. Urine dipstick. The finding of red and white blood cells in your urine when examined under the microscope is highly suggestive of an infection. However, the diagnosis can be quickly qualified by using a dipstick test (combur 9) which will react positively to white blood cells and nitrites that the bacteria produce [Fig 2]. This takes only a minute to do.

2. Urine culture. However, infection only be confirmed by obtaining a mid stream urine specimen for culture to isolate the offending bacteria and identify the effective antibiotics against it. Most laboratories can give results of urine culture within 48 hours. Occasionally, the same bacteria can be identified in the blood.

Fig 2. Urine combur 9 test strips which contain reagents that react positively when there is an excess of pus cells and bacteria in the urine.

3. Ultrasound. A screening ultrasound can easily be done in the clinic. This may reveal bladder or kidney stones [Fig 3].

Fig 3. Ultrasound of the bladder showing a stone as the cause of recurrent cystitis

4. Xrays. If ultrasound reveals a stone or an abnormal kidney, then a special X-ray of the urinary tract called intravenous urogram (IVU) is indicated [Fig 4]. This X-ray is also done in patients with recurrent infections as there may be an abnormal urinary system eg. duplex ureter which allow urine to reflux up.
Fig 3. Ultrasound of the bladder showing a bladder stone as the cause of recurrent cystitis

Fig 4. IVU of an infected left kidney due to stones

5. Cystoscopy. Occasionally, this telescope inspection of the bladder is carried out to rule out associated bladder disease, particularly bladder tumours [Fig 5]. This is done under local anaesthesia.

Fig 5. Flexible cystoscope to visualize the bladder

Recurrent Infections
Many women suffer from frequent UTI's. Nearly 20 percent of women who have a UTI will have another, and 30 percent of those will have yet another. Of the last group, 80 percent will have recurrences. It is well known that some women are more prone to get recurrent attacks than others.

Research had shown that women with certain blood types are particularly prone to UTI's because the cells lining the vagina and urethra may allow bacteria to attach more easily. Another common reason for recurrent UTI is the persistence of resistant bacteria that was not eradicated the last time round.

The widespread use of antibiotics have resulted in resistant strains which remain in the lining of the urethra / bladder. Doctors often give antibiotics based on 'best guess' but do not realize that the bacteria is only partially sensitive to the antibiotics, resulting in incomplete eradication. Hence, it is important to do a urine culture prior to starting antibiotics to determine if one is dealing with such a resistant strain of bacteria.

Treatment
The mainstay of UTI treatment is an appropriate and adequate antibiotic course. An uncomplicated UTI can be cured with 3 days of treatment. The choice of drug and length of treatment depends on the patient's history and the urine tests that identify the offending bacteria.

The sensitivity test is especially useful in helping the doctor select the most effective drug. The drugs most often used to treat uncomplicated UTI's are trimethoprim, trimethoprim/sulfamethoxazole (Bactrim), amoxicillin (Amoxil), nitrofurantoin, ampicillin and newer antibiotics such as ciprofloxacin (Ciprobay), and oflaxacin (Tarivid).

Single-dose treatment is not recommended for some groups of patients, for example, those who have delayed treatment or have signs of a kidney infection, patients with diabetes or structural abnormalities, or men who have prostate infections.

Longer treatment is also needed by patients with infections that also affect the prostate or the testis. It is important to take the full course of treatment because symptoms may disappear before the infection is fully cleared.

A pregnant woman who develops a UTI should be treated promptly. Only certain antibiotics are advisable during pregnancy. Kidney infections generally require 2 weeks of antibiotic treatment. Prostate infections usually need up to a month.

Drugs are also available to relieve the pain of UTI, eg. flavoxates (Genurin, Urispas). Urine alkalinizing agents such as citrate and bicarbonate can also alleviate the irritative symptoms associated with UTI.

a) in Women
Women who have frequent recurrences with no identifiable cause may benefit from preventive therapy. About 4 out of 5 women who have a UTI get another in 18 months. Many women have them even more often. A woman who has frequent recurrences (three or more a year) should ask her doctor about one of the following treatment options:

Take a low dose of an antibiotic daily for 3 to 6 months, eg. bactrim, nalidixic acid, amoxil. (If taken at bedtime, the drug remains in the bladder longer and may be more effective.)
Take a single dose of an antibiotic after sexual intercourse and empty the bladder prior to bedtime.

Additional steps that a woman can take on her own to avoid an infection:

Drink plenty of water every day. Drinking cranberry juice can also help because it inhibits the growth of some bacteria by acidifying the urine. Vitamin C (Ascorbic Acid) supplements have the same effect;
Urinate when you feel the need; don't hold the bladder for too long because stale urine is a good medium for bacteria to grow
Wipe from front to back to prevent bacteria around the anus from entering the vagina or urethra;
Pass urine immediately after sexual intercourse
Avoid excessive talcum powder over the genital area
Cut down on the consumption of sugar and sweets whilst increasing dietary fibres.

b) in Men
UTI's are unusual in men. In older men (age 50 years and beyond), it usually stems from an obstruction of the bladder, usually by an enlarged prostate (BPH). The residual urine stagnates and gets infected easily [Fig 6].

Fig 6. BPH causing bladder blockage and residual urine

In younger men aged 20 to 50 years, prostate infection (prostatitis) is a common occurrence. Prostatitis can been classified into the following categories:
1) acute bacterial prostatitis
2)chronic bacterial prostatitis
3) nonbacterial prostatitis, prostatodynia and chronic pelvic pain syndrome.

Symptoms
The signs and symptoms vary depending on the various types of prostatitis.
1) Acute bacterial prostatitis [Fig 7]
The symptoms come on suddenly and may include:

Fever and chills
Pain in the pelvis, lower back or groin
Urinary problems, including increased urinary urgency and frequency, difficulty or pain when urinating, sudden retention of urine, and blood in the urine
Painful ejaculation

Acute prostatitis can be a serious condition and requires intravenous antibiotics because of the fever and severe pain.

Fig 7.Acute bacterial prostatitis : the prostate is swollen and extremely tender

2) Chronic bacterial prostatitis
This type of prostatitis develop more slowly and usually not as severe as acute prostatitis. In addition, the symptoms of pain tend to alternate with times when symptoms are better. These symptoms include:

A frequent and urgent need to urinate, both day and night
Burning sensation when urinating (dysuria)
Pain in the pelvic area
Pain in the lower back and scrotum
Pain felt at the penis tip at the end of micturition
Difficulty starting to urinate, or diminished urine flow
Blood in semen or in urine
Painful ejaculation

3) Chronic nonbacterial prostatitis
The symptoms of nonbacterial prostatitis are similar to those of chronic bacterial prostatitis. The only way to determine whether prostatitis symptoms are caused by bacterial infection or are nonbacterial is through lab tests to find out whether bacteria is present in the urine or prostate / semen fluid.

Another suspect is reflux of urine into the prostate due to a non-relaxing urinary sphincter eg. from psychological stress, excess caffeine.

Causes
Bacteria normally found in the large intestine typically cause acute prostatitis. Most commonly, acute prostatitis originates in the prostate, but occasionally the infection can spread from a bladder or urethral infection.

For chronic bacterial prostatitis, it is not entirely clear what causes this chronic bacterial infection. It may develop after an episode of acute prostatitis when bacteria still remain in the prostate. Or it may begin as a low-grade infection due to obstruction of the prostatic ducts.

Diagnosis
Diagnosing prostatitis is by clinical means. The medical history is as outlined in the symptom list and performing a physical exam to check the pelvic area for tenderness and doing a digital rectal exam for prostate swelling and tenderness.

a) Digital rectal exam [Fig 8]
During a digital rectal exam, if the prostate gland is enlarged, indurated and tender to the touch, prostatitis is confirmed.

Fig 8. Digital rectal exam of the prostate

b) Urine & semen tests
These may also be done to determine the source and type of organism.

Treatment
The main treatment for acute bacterial prostatitis is antibiotics. In acute prostatitis, one may need to be hospitalized for a few days to receive antibiotics intravenously, followed by oral antibiotics for a week.

For treatment of chronic nonbacterial prostatitis, a long course of oral antibiotics eg. doxycycline, bactrim, ciprobay, is given for 1 to 3 months. For chronic nonbacterial prostatitis, medications like anti-inflammatory drugs and alpha-blockers can be tried. In refractory cases, botox injections can be given into the prostate.