Overview
A urinary tract infection (UTI) is an infection that affects any part of the urinary system, including the kidneys, ureters, bladder, and urethra.
Most infections involve the lower urinary tract – the bladder and the urethra.
Signs and Symptoms
Lower UTI (Cystitis - Infection of the Bladder):
Dysuria: Pain or burning sensation during urination.
Increased Frequency: Needing to urinate more often than usual.
Urgency: A strong, persistent urge to urinate.
Cloudy Urine: Often a sign of pus in the urine (pyuria).
Haematuria: Blood in the urine, which may appear pink, red, or cola-colored.
Strong-smelling Urine: A notable change in the odor of the urine.
Pelvic Pain: Especially in women, around the area of the pubic bone.
Upper UTI (Pyelonephritis - Infection of the Kidneys):
Flank Pain: Pain in the back or side, usually below the ribs.
Fever and Chills: High temperature and shivering.
Nausea and Vomiting: Associated with the systemic infection.
Fatigue: General feeling of being unwell.
In Older Adults:
Altered Mental Status: Confusion or delirium.
Incontinence: Sudden onset or worsening.
Weakness and Falls: Increased risk of falling.
Types of UTIs
1. Uncomplicated UTIs:
Occur in otherwise healthy individuals with a normal urinary tract.
2. Complicated UTIs:
Occur in individuals with structural or functional abnormalities of the urinary tract, or who have other underlying health conditions, such as diabetes or immunosuppression.
Etiology
Common Pathogens:
Escherichia coli (E. coli): Responsible for approximately 70-90% of uncomplicated UTIs.
Staphylococcus saprophyticus: Common in sexually active young women.
Other Gram-negative Bacilli: Proteus, Klebsiella, and Enterobacter species.
Gram-positive Bacteria: Enterococci and streptococci.
Risk Factors:
Female Anatomy: Shorter urethra increases the risk.
Sexual Activity: Can introduce bacteria into the urinary tract.
Menopause: Decreased estrogen levels can change the urinary tract, making infections more likely.
Urinary Catheters: Can introduce bacteria directly into the bladder.
Blockages: Kidney stones or an enlarged prostate can trap urine in the bladder.
Immune System Suppression: Diabetes or other conditions that impair immune function.
Pathogenesis
Bacterial Ascension: Bacteria typically enter the urinary tract through the urethra and begin to multiply in the bladder.
Invasion and Colonization: Pathogens adhere to the bladder wall, evading the immune system, and cause inflammation and infection.
Potential Spread to Kidneys: If the infection is not treated, bacteria can ascend the ureters to the kidneys, causing pyelonephritis.
Diagnosis
Urinalysis: Test of urine sample to detect the presence of white blood cells, red blood cells, or bacteria.
Urine Culture: To identify the specific bacteria causing the infection and to determine antibiotic sensitivity.
Imaging Studies: Ultrasound or CT scan in recurrent or complicated cases to check for structural abnormalities.
Cystoscopy: In chronic cases to examine the bladder and urethra.
Treatment
Uncomplicated Lower UTI:
I. Antibiotics: Commonly prescribed antibiotics include trimethoprim-sulfamethoxazole, nitrofurantoin, fosfomycin, and amoxicillin-clavulanate.
II. Pain Relief: Phenazopyridine can help relieve symptoms of urinary discomfort
Complicated UTI and Pyelonephritis:
I. Longer Course of Antibiotics: May include ciprofloxacin, levofloxacin, or ceftriaxone.
II. Intravenous Antibiotics: For severe infections or hospitalized patients.
III. Supportive Care: Hydration and pain management.
Recurrent UTIs:
I. Prophylactic Antibiotics: Low-dose antibiotics taken regularly or after sexual activity.
II. Lifestyle Changes: Increased fluid intake, urinating after intercourse, avoiding irritating feminine products.
Prevention
Hydration: Drinking plenty of water to help flush bacteria from the urinary tract.
Hygiene: Wiping from front to back after urinating and bowel movements to prevent bacteria from spreading from the anal area to the urethra.
Urinate Frequently: Avoid holding urine for long periods.
Clothing: Wearing cotton underwear and loose-fitting clothing to keep the area around the urethra dry.
Avoiding Irritants: Using unscented personal hygiene products.
Special Considerations
Pregnant Women:
Increased Risk: Due to hormonal changes and pressure on the bladder.
Screening and Treatment: Important to prevent complications such as preterm labor.
Men:
Less Common: Often associated with prostate problems or urinary catheter use.
Thorough Evaluation: Required to identify underlying causes.
Children:
Symptoms: May include bedwetting, poor appetite, irritability.
Prompt Treatment: To prevent kidney damage.
UTIs are common and generally respond well to treatment, but early diagnosis and proper management are crucial to prevent complications, particularly in vulnerable populations like pregnant women, older adults, and individuals with underlying health conditions.