Urinary Tract Infections
Types of Infections & Treatments
About Urinary Tract Infections
What Is Urinary Tract Infection (UTI)?
A Urinary Tract Infection (UTI) is defined as the presence of significant bacteria (usually defined as > 100,000 colony forming units of bacteria (CFU) per ml) and increased white cells (> 10/ul) on microscopic examination of the voided urine. UTIs can occur in any part of the urinary system. The most common site involves the lower urinary tract, especially the bladder and is called cystitis. Hence, it is important to seek medical advice or assistance from a specialist when symptoms are clearly detected.
Epidemiology of UTIs:
Females are more prone to urinary tract infections than males with a ratio of 1:10. The reason is anatomical as the female urinary tract infection is shorter and much closer to the anal area and gastrointestinal tract. Males over 50 years old frequently get UTI due to prostate enlargement which causes retention of urine And voiding dysfunction. Kidney stones and use of urinary catheters also increase risk of UTI. In Singapore, 50% of females will experience UTI at least once during their life with 20% of women aged 20 to 65 years suffering at least 1 attack of UTI per year.
Common Pathogens Causing Urinary Tract Infections:
The common gastrointestinal bacteria, Escherichia coli, accounts for almost 90% of community-acquired UTI. Proteus species often cause infection in the kidneys and are associated with stone formation in the urinary tract.
Bacteria may spread in a retrograde manner from the lower urinary tract and involve the upper tract (kidneys). Pregnancy, diabetes, and retention of urine caused by obstruction are predisposing factors for upper tract disease. Infective endocarditis and sepsis from distant sites may also involve the urinary tract through bacteremia (bacteria in the bloodstream). Chronic UTI may progress from acute infection and cause renal inflammation and scarring which may lead to irreversible kidney damage.
Clinical Presentation
- A strong persistent urge to urinate (Urgency)
- Smelly urine (Malodorous urine)
- Frequent urination at night (Frequency)
- A burning or painful sensation during urination (Dysuria)
- Passing frequent, small amounts of urine and sensation of incomplete emptying (Stranguria)
- Cloudy or reddish-coloured urine (Turbid urine)
- Fever and/or chills, flank tenderness and pain and vomiting may indicate kidney involvement
Diagnostic Tests for Urinary Tract Infection:
Diagnosis of UTIs is based on the detection of high bacteria counts and increased white cells on microscopic examination of a urine sample. Urine collection should be a midstream clean catch sample or from urinary catheters. Microscopy of the urine sample will determine if there is UTI by counting the number of bacteria and white cells.
Blood tests are necessary if there is fever >38C. These help to determine the severity of infection, evidence of kidney damage and to exclude the presence of bacteria circulating in the blood.
However, an ultrasound or CT examination of the kidneys may be needed if upper tract involvement is suspected. For recurrent UTIs, a cystoscopy may also be performed. This involves insertion of a long thin tube with a lens to visualise the lower urinary tract and bladder.
Treatment of Urinary Tract Infection
Antibiotics are usually given for 3 days for mild lower urinary tract infections like cystitis. For severe infections, especially involving the kidneys, intravenous antibiotics may be required and the treatment is prolonged. UTIs associated with obstruction by stones in the urinary tract are often serious and many such patients will require hospital admission for intravenous antibiotics and removal of the stone(s). In this case, it is highly advisable to seek specialist treatment.
Prevention of UTIs:
UTIs can be prevented with good hygiene (wiping from front to back and cleansing the genital area after intercourse). Increase fluid intake (>2.5 litres daily) and urinating frequently provides a flushing action that may reduce UTI. Douches have been associated with increased incidence of UTIs and over-douching should be avoided. Cranberry juice may have infection-reducing properties through change of urine pH and drinking it daily may help prevent UTIs in some patients (limited evidence). Surpression antibiotics may be needed for troublesome recurrent UTI. Lately, there is evidence of benefit from a novel ‘UTI vaccine’ (Uromune®) for patients who have failed other modalities.
Points to Note:
The only way to eradicate TB is early diagnosis and treatment. The key to complete cure is 100% compliance to the full treatment course. This is also the key to control of TB in a population.
There is a lot of research in TB in the areas of new vaccines that will make it more effective in preventing TB and newer TB drug regimens which will allow us to cure TB with a shorter course of treatment.
If you are concerned about tuberculosis, please contact your family physician or call our clinic for an appointment with one of our infectious disease physicians