Home > Uncategorized > Urinary Tract Infection

Urinary Tract Infection

What is the urinary tract?

The urinary tract consists of two kidneys, the two ureters, the bladder and the urethra.

What is urinary tract infection (UTI)?

Urinary tract infection (UTI) encompasses a variety of clinical entities :

  • Asymptomatic bacteriuria (bacteria detected in the urine but with no symptoms)
  • Cystitis (infection of the bladder)
  • Pyelonephritis (infection of the kidney)

How common is urinary tract infection?

  • UTI is more common in females. In women about 50% – 80% acquire at least one UTI during their lifetime which is mostly uncomplicated cystitis.
  • The annual incidence of pyelonephritis was approximately 28 per 10,000 women.
  • UTI is rare in young men.
  • In the elderly age group, benign prostatic hyperplasia has been implicated as a common predisposing factor for UTI.
  • In men, a single episode of UTI has to be investigated particularly if the patient is in the younger age group.
  • In children, link to UTI in children

What are the risk factors for urinary tract infection?

Risk factors associated with UTI are :

  • Recent sexual intercourse (honeymoon cystitis) – in women
  • Abnormalities in the urinary tract such as congenital duplex urinary systems, putflow obstruction and vesico-ureteric reflux
  • Diabetes
  • Urinary incontinence in women and benign prostatic hyperplasia in men
  • Kidney stones
  • Pregnancy
  • Postmenopausal changes in the urethra and vagina (Atrophic Urethritis and Vaginitis)
  • Urinary catheterization

Table 1 : Incidence of Urinary Tract Infection According to Age and Sex

Age Group
Incidence (%)
Approximate Sex Ratio (Male:Female)
Preschool age
1.5 – 3.0
School age
Reproductive age
3 – 5
10 – 30

What causes urinary tract infection?

Various organisms have been implicated such as :

  • Escherichia coli (80% – 85%)
  • Staphylococcus saprophyticus (5% – 15%)
  • Klebsiella species (more common in hospital acquired UTI)
  • Proteus species (more common in hospital acquired UTI)
  • Pseudomonas aeruginosa (more common in hospital acquired UTI)
  • Candida
  • Enterococci and other organisms.

How do I know I have a urinary tract infection?

The clinical presentation of UTI is quite variable, ranging from

1. Asymptomatic bacteriuria – no symptoms

Bacteriuria detected in the absence of symptoms does not warrant antimicrobial therapy except in specific settings. These include pregnancy, before surgery or instrumentation of the urinary tract and after renal transplantation. Treatment of asymptomatic bacteriuria in patients who are immunosuppressed because of transplantation other than renal (i.e. other solid organ or bone marrow) or because of neutropenia has not been well studied and is not currently recommended as standard practice.

2. Signs and symptoms of lower urinary tract infection :

  • cystitis and urethritis
    • discomfort as passing urine(dysuria)
    • increased urinary frequency
    • increased urgency
    • increased night time voiding (nocturia)
    • lower abdomen pain or discomfort
    • cloudy /smelly/bloody urine

3. Signs and symptoms of kidney infection :

  • Acute pyelonephritis
    • fever, chills and rigors
    • loin/back pain (with positive renal punch) occasionally radiating to waist
    • nausea and vomiting
    • +/- symptoms of cystitis
    • septic shock – mental changes and confusion, poor appetite, low blood pressure, cold and clammy peripheries

You should consult a doctor. A medical history, physical examination and investigations have to be done.

Investigations for UTI

1. Urinalysis – a mid-stream(clean catch) urine sample is required.

How to obtain this sample?

  • First wash your hands thoroughly with soap and water. Then wash the penis or vulva area with front to back strokes preferably using a soapy sponge or gauze provided.
  • Start urination into the toilet bowl. Stop after a few drops.
  • Position the container to catch the middle portion of the stream.
  • Once the sample is obtained, complete voiding into the toilet bowl.
  • Close the container lid tightly to avoid spillage and contamination.

Various tests are carried out on this sample to confirm the diagnosis.

  • Urine microscopy and dipstick
  • Urine Culture and Sensitivity

2. Your doctor may request further tests such as blood tests look at your kidney function and to ensure that you are not diabetic.

3. Other investigations e.g. ultrasound may be required

What is the treatment of UTI?

In general, asymptomatic UTI does not require treatment. However, symptomatic infection requires antibiotics which can be given as an out-patient basis. Your doctor may request for admission if you are severely ill, cannot tolerate oral medication, or have complicating medical conditions for intravenous therapy.

Treatment with antimicrobial agents is not sufficient. The cause for the UTI has to be ascertained.

Prevention of UTI

  • Maintanence of good fluid intake of at least 2-3 liters a day
  • Maintanence of good genital and urinary hygiene
  • Urinate frequently especially after sexual intercourse (women)
  • Avoid sex with multiple partners
  • Avoid douches and feminine hygiene sprays
  • Choose sanitary napkins instead of tampons. To be changed after each urination.
  • Use cotton based underwear and avoid tight fitting pants.
  • Cranberry juice

I am pregnant and I think I have a UTI? Please help.

There are major differences between the approach to UTI in pregnant women.

  • Asymptomatic bacteriuria is actively sought and is aggressively treated (in non-pregnant women screening for asymptomatic bacteriuria is not recommended)
  • Short-course therapy is the treatment during pregnancy for patients with uncomplicated cystitis and asymptomatic bacteriuria. However, the drugs that can be safely used are limited for pregnant women.
  • Follow-up of patients with bacteriuria during pregnancy is more intense, with more rapid use of prophylactic strategies in pregnant women with recurrent bacteriuria.

What is the prognosis of UTI?

Asymptomatic bacteriuria does not itself cause an increase in mortality.

A urinary tract infection can be recurrent (reoccurs after the completion of treatment) or relapsing (reoccurs during the course of the therapy).

Recurrent infections can lead to chronic pyelonephritis or to renal failure.

Last reviewed : 26 April 2012
Writer : Dr. Anita Bhajan Manocha
Reviewer : Dr. Sunita a/p Bavanandan