Urinary Tract Infection (UTI)

Urinary tract infections are among many common conditions responsible for frequent doctor visits. UTIs affect all age groups including children, adult men and women and elderly people. About 150 million cases of urinary tract infections are recorded every year all over the world. Women get UTIs more than men. In women, UTIs are most common in the age group of 15 to 49 years and during pregnancy. In India, 3% to 24% of pregnant women get UTIs without any symptoms (asymptomatic bacteriuria) due to the changes in the body that occur during pregnancy. Reinfection or recurrence of UTIs is observed in 40% of women who are not pregnant. Since women have a shorter urethra, it makes them prone to frequent infections and relapses with or without symptoms. Reappearance or recurrence of infection or symptoms can occur as a result of inadequate treatment, lack of self-care, antibiotic resistance, weak immune system, diabetes, and blockages anywhere in the urinary tract.

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Urinary tract infections can be complicated, uncomplicated and asymptomatic on the basis of symptoms and severity of the infection.

• Uncomplicated urinary tract infection
  This type of UTI is seen in healthy people who do not have any underlying structural abnormalities (such as blockages or abnormal growth) or neurological conditions (related to the nervous system) in their urinary tract which could make them prone to UTI. Uncomplicated UTI is of two types, depending on the site of infection:
  • Upper urinary tract infection
    This involves the upper part of the urinary tract such as kidneys (as in pyelonephritis). Although rare, pyelonephritis is a serious form of infection that can result in kidney damage or death.
  • Lower urinary tract infection
    In this type of UTI, the lower part of the urinary tract is involved such as the urinary bladder (cystitis). It is common in women and in people with a history of UTIs, diabetes, obesity, a high sexual activity, and women with vaginal infection.
• Complicated urinary tract infections
  This type of infection occurs in people who have an underlying condition such as an obstruction or blockage in the urinary system, neurological problems of the urinary tract that cause collection or retention of the urine, kidney failure or transplant, a weak immune system, kidney (renal) stones, a catheter in the bladder (indwelling catheter), elderly people and women who are pregnant.
• Asymptomatic bacteriuria
  It is the condition in which a person has an infection but there are no symptoms of UTI. Although healthy people could get this type of UTI, it is common in adult women, especially those who are pregnant or approaching menopause, people with diabetes, a catheter in the bladder, spinal cord injury, and elderly people. Asymptomatic bacteriuria is generally diagnosed after urine analysis because of the absence of symptoms.

The infection-causing bacteria enter the urinary system through the urethra, attack the inner lining of the urinary tract and depending on the location (bladder, urethra, kidneys) that is prone to bacterial growth and multiplication. Uncontrolled growth of bacteria causes inflammation and redness along with various other symptoms such as:

• Burning sensation or pain while passing urine, chiefly due to irritation in the urinary bladder. (Read more - Painful urination treatment)
• Pain in the lower abdomen is also associated with burning sensation while urinating due to bladder inflammation. (Read more -  Stomach pain causes and treatment)
• Pain in flanks or in the back occurs in severe kidney infection.
• Sudden urge to pass urine when bladder is empty or after passing urine.
• Occasionally, the person may also lose control of urine.
• Frequent sensation or urge to pass urine.
• Bad urine odour.
• Change in the colour of the urine to pink (blood-stained), dark yellow, cloudy due to the presence of white particles.
• High fever with chills is common in high-grade infections and infection of the kidneys.
• Generalised body weakness and fatigue.
• Nausea and/or vomiting may be present with severe infection.
• Sometimes in severe cases, blood in the urine can be seen.

UTIs in children present with:

• Fever with chills.
• Cloudy or hazy appearance of urine.
• Foul urine odour.
• Loss of appetite.
• Vomiting may be present in some children.
• Purposefully holding the urine in the bladder or crying intensely while passing urine due to pain or burning sensation.
• Babies with urinary tract infection may wet their clothes frequently.

Causes

Various bacteria and fungi are responsible for causing infections in the urinary tract. Some of the most common ones include Escherichia coli (E. coli), Proteus mirabilis, Klebsiella pneumoniae, Enterococcus faecalis, and Staphylococcus saprophyticus.

Risk Factors

Multiple risk factors can increase a person’s risk of getting urinary tract infections. These differ in males and in females and include:

Risk factors in males

• Obstruction or blockage in the urinary tract after the use of instruments (for dilating a narrowed urethra), a catheter in the urinary bladder or surgery of the urinary tract.
• Enlarged prostate gland results in an incomplete blockage of the urinary tract which leads to the development of urinary infections in men above 50 years of age.
• Use of catheter in men with diabetes.
• Men older than 50 years of age.
• Acute UTIs (such as acute cystitis) are common in homosexual young men, men who have unprotected sex with an infected female partner, HIV positive men, and more.

Risk factors in females

• Women are at high risk of contracting UTIs due to the short length of the urethra.
• Pregnancy increases the risk of UTIs due to hormonal changes in the body, which sometimes lead to vaginal infections. An infection of the vagina may eventually spread to the urinary system. (Read more - Hormonal imbalance causes and symptoms)
• Menopause also poses women to a higher risk of developing UTIs due to a loss of the protective effect of oestrogen against bacterial infections. As the woman stops menstruating, her serum oestrogen level declines.
• Presence of a catheter in the bladder for a long time increases the risk of urinary tract infections.
• High sexual activity in women has also been found to increase the possibility of contracting UTIs.
• A woman with a history of urinary tract infection is at a greater risk of contracting the infection again as compared to others.
• Diabetes mellitus increases the availability of glucose for bacteria to feed on, prolong the healing time along with decreasing the immunity of the person over a period of time. As a result, the risk of contracting a UTI also increases.

Urinary tract infections can be prevented to some extent by following certain precautions in a day-to-day life. Here are some ways that can help you in staying away from UTIs:

• Drink 1-2 litres of water to hydrate your body adequately and avoid recurrent UTIs.
• Limit the intake of alcohol and caffeinated drinks as they cause irritation of the inner lining of the urinary bladder.
• Make sure that you pass urine right before and after having sex to prevent UTI.
• Avoid bath oils or bubble baths. Bathing under running water like showers is more effective in cleaning the body than taking bath in a tub.
• Avoid using tight fitting inner wears. Cotton undergarments are better than synthetic ones.
• Opt for sanitary pads instead of tampons. Sanitary pads instead of tampons decrease the risk of urinary tract infections.
• Little girls should be taught to clean the genital area from front to back while potty training.
• Avoid use of spermicide foam or spray as a contraceptive on the genital area as it increases the risk of urinary tract infection.
• Urinary catheters should not be kept in place beyond the required duration.
• Application of low-dose oestrogen in the genital area can help in preventing the growth of bacteria in post-menopausal women.
• Treatment of underlying problems (such as enlarged prostate, prolapse of the uterus in women, among others) that cause incomplete drainage of urine prevents urinary tract infections.
• Structural abnormalities should be corrected with surgery in order to prevent recurrent urinary tract infections.
• Few scientific research studies show that cranberry helps in decreasing the risk of recurrent UTIs in women and children. Hence, the consumption of cranberries or cranberry juice may help in preventing UTIs.
• Vitamin C helps in making the urine more acidic which subsequently stops the growth and multiplication of bacteria.
• Probiotics or good bacteria supplements help in preventing urinary tract infections by stopping the growth of bad bacteria or infection-causing bacteria. Probiotics are present in yoghurt and cheese as well.

A diagnosis of UTI is established on the basis of:

Urine Analysis
Urine analysis is an efficient test that helps the doctor in the diagnosis of infection in the urinary tract. A midway stream urine sample is used for a urine analysis test. The test includes the following components:

• Physical examination of the urine.
  • Colour
    Urine may appear clean, transparent, cloudy or hazy in case of infection.
  • Acidity
    Normal urine is slightly acidic with a pH of 6.0 to 7.5. The pH is high (8.5 to 9.0) in the case of an infection.
  • Nitrite test
    The test is performed using a dip-stick (a measurement instrument that is dipped in a liquid to perform a test). A positive nitrite test confirms the diagnosis of urinary tract infection. The nitrite test is specific for UTIs in 90% of the cases.
  • Leukocyte esterase test
    It helps to detect white blood cells in urine that appear due to inflammation and infection. The test is 55% specific for detecting urinary tract infections.
  • Blood in urine (haematuria)
    It is commonly seen in UTIs and helps in differentiating UTIs from other infections of the vagina in which urine does not contain red blood cells.
  • Urine culture test
    A sample of urine collected for the test is kept in a testing dish containing an artificial culture medium in the lab at a temperature same as that of the body. Bacterial growth is seen if the urine sample contains bacteria. A sample of this bacterial growth is then seen under the microscope to identify the type of bacteria, which helps in choosing suitable antibiotics for the treatment of the urinary tract infection.

Complete blood count (CBC) and Blood culture

CBC and blood culture are performed to confirm the diagnosis of infection and to identify the type of bacteria causing the infection respectively. These tests help to choose the right antibiotic for the treatment of urinary tract infection.

Plain X-ray

This test is performed to detect kidney stones which might be the possible cause of urinary tract infection.

Ultrasonography scan (USG scan)

A USG scan helps in measuring the amount of urine left in the bladder after urination. This helps in diagnosing urine retention or incomplete emptying of the urinary bladder. The USG scan also helps in detecting the collection of pus (abscess) in the kidneys in case of a severe form of infection, abscess in the prostate gland among others.

Cystoscopy

A cystoscopy is used when the doctor suspects’ pathologies related to the urinary bladder such as a tumour, diverticulum, and more. A tube (laparoscope) with a camera at its tip is passed into the bladder to visualise the inside of the urinary bladder.

Computed tomography scan (CT scan)

CT scan helps in detecting kidney stones that cause UTIs due to obstruction or blockage in the flow of urine in the urinary tract. In a contrast-enhanced CT scan, a three-dimensional image is formed after injecting a contrast dye in the body. This helps in detecting obstructions in the urine flow such as renal stones, infection, tumour, cyst, and others.

Intravenous pyelogram (IVP) and Voiding cystourethrogram (VCUG)

Both the imaging tests are performed to detect an obstruction or blockage in the urine flow in the urinary tract. The test involves the injection of a chemical dye through a vein in the arm (in IVP) and the bladder (in VCUG) and then an X-ray image is taken while the dye travels through the urinary tract.

Magnetic resonance imaging (MRI)

It is used for visualising an abscess, tumour, cyst, and other abnormalities in the kidneys. MRI forms a clear image of the organs in the body.

Medicines

Medicines are used to treat urinary tract infections and to prevent the infection from spreading to the kidneys. Medicines are also used to relieve the symptoms of urinary tract infections. Uncomplicated urinary tract infections usually resolve after taking antibiotics.

• Trimethoprim-sulfamethoxazole is the first choice of antibiotics used for treating uncomplicated UTIs.
• Nitrofurantoin is an antibiotic that kills bacteria. It is indicated in UTIs caused by E. coli, Staphylococcus aureus, Klebsiella, and other bacteria. It is commonly used in the treatment of bladder infection (cystitis).
• Other antibiotics used in the treatment of uncomplicated UTIs include Fosfomycin, trimethoprim, fluoroquinolones, ciprofloxacin, etc.
• Ofloxacin and levofloxacin are used in the treatment of both complicated and uncomplicated UTIs.
• Amoxicillin and ampicillin are used to treat complicated UTIs.
• Cephalosporins are stronger antibiotics (second generation) that are used for treating uncomplicated UTIs in the bladder.
• A class of antibiotics, Aminoglycosides, are used in the treatment of complicated UTIs.
• In the case of recurrent urinary tract infections, the doctor may advise a single dose of antibiotic daily and after sexual intercourse.
• Phenazopyridine helps in relieving pain, discomfort, and irritation of bladder caused by infection.

Surgery

A surgery is performed for the treatment of recurrent UTIs in conditions such as abnormalities present since birth (e.g. vesicoureteral reflux, neurogenic bladder, and phimosis), abnormalities that develop later in life (e.g. renal stones, foreign bodies such as catheters, complication of sexually transmitted diseases, obstruction due to enlarged prostate among others), obstruction due to tumour, cyst or collection of pus and more.

Different types of surgeries include bladder surgery which is performed in severe cases of complicated UTIs. These surgeries include:

• Urinary diversion, orthotopic diversion
  The flow of urine is diverted away from the bladder so that it collects in a bag that is attached outside the body.
• Augmentation cystoplasty
  The bladder is removed, and a new urinary bladder is constructed using a part of the intestine.
• Urethral stent
  It is used to dilate blocked urethra caused by urinary tract infection.
• Laser surgery
  Blockages are removed with the help of surgery performed through endoscope or laparoscope using laser rays.

Lifestyle management

Urinary tract infections have a tendency to reappear after treatment in the absence of certain lifestyle modifications. Although the uncomplicated form of UTIs recover with medicines, they tend to appear again. Self-care is essential to decrease the risk of reinfection after surgery that is performed to correct the abnormalities that resulted in complicated UTIs. Here are a few helpful tips:

• Drink a good amount of water in order to maintain a good urine flow.
• Do not hold when there is an urge to pass the urine.
• Restrict the intake of alcohol and caffeine.
• Avoid tight-fitting undergarments.
• Women should learn the correct methods of cleaning (from front to back) the genital area in order to maintain good hygiene.
• Incorporate healthy habits of keeping yourself clean by taking regular showers. Avoid bubble baths.
• Use barrier method of contraception or birth control pills instead of spermicidal gels or sprays in order to prevent infections.
• Take appropriate measures to keep your diabetes under control, as it increases the chances of urinary tract infections.

Prognosis

Most people with uncomplicated UTIs generally recover in 1 to 2 days. However, it is necessary to complete the full course of antibiotics as advised by the doctor, due to the high chances of developing resistance to the antibiotics.

Severe and/or complicated infections that require surgery for correction may take longer to get better.

Infection in the kidneys takes 1 week or more for complete recovery and disappearance of the symptoms.

Overall, a person with UTI recovers fully if he/she:

• Has an uncomplicated UTI.
• Is of a relatively younger age group with a healthy immune system.
• Completes the course of antibiotics along with other medications as prescribed by the doctor.
• Makes lifestyle changes such as staying adequately hydrated and maintaining genital hygiene.

The outcome is not very good in people with severe infections who have kidney damage, diabetes, a weak immune system and are elderly.

Complications

Complications arising from urinary tract infections include:

• Sepsis
  It is a life-threatening condition that results when the infection spreads in the blood. Children, old people or those with a weak immune system are at a higher risk of developing sepsis.
• Kidney damage
  Damage caused to the kidneys (scarring) due to severe infection is permanent and cannot be cured.
• Premature labour
  Urinary tract infection during pregnancy increases the risk of premature labour and infection in the kidneys.
• Relapse of infection
  Recurrence or relapse of infection is a common complication of urinary tract infections.
• Urethral Stricture
  Narrowing of the urethra is common in men due to recurrent urinary tract infections (urethritis).