Urinary Tract Infections are infections in any part of the urinary system, the kidneys, bladder or urethra.

Common Terminology Related to the Urinary System

Proteinuria is characterized by the presence of proteins in the urine exceeding 150mg per day, suggesting potential renal impairment or damage.

Hematuria refers to the presence of blood in the urine, indicating bleeding within the urinary tract.

Crystalluria is identified by the presence of crystals, such as oxalates or phosphates, in the urine, detectable through microscopic urine analysis.

Glycosuria denotes the presence of glucose in the urine, which may be associated with diabetes mellitus or renal glycosuria.

Azotemia signifies an elevation in the serum concentration of urea and creatinine beyond their normal ranges, often associated with reduced glomerular filtration rate (GFR) in the kidneys due to renal failure, also know as “uremia”.

Oliguria is defined as a reduced urine output, specifically less than 100ml within a two-hour period.

Anuria is the complete cessation of urine production.

Dysuria describes difficulty or pain experienced during urination.

Polyuria is characterized by an excessive urine volume, exceeding 3 liters per day.

Urinary retention arises from an obstruction hindering urine outflow from the bladder, typically necessitating catheterization for relief.

Overview of Urinary Tract Infections

The lower urinary tract comprises the bladder and urethra. Infections in this region can manifest as urethritis (urethra infection), cystitis (bladder infection), or prostatitis (prostate gland infection).

Upper urinary tract infections (UUTIs) involve the upper parts of the urinary tract, including pyelitis and nephritis/pyelonephritis.

Etiological Agents of Urinary Tract Infections

• Escherichia coli

• Group B Streptococcus

• Klebsiella pneumoniae

• Proteus species

• Enterobacter species

• Enterococcus species

• Staphylococcus

Individuals at Increased Risk of Urinary Tract Infections

• Individuals with conditions causing urinary tract obstruction, such as kidney stones.

• Individuals with medical conditions leading to incomplete bladder emptying, like spinal cord injuries or post-menopausal bladder decomposition.

• Individuals with compromised immune systems, such as those with HIV/AIDS or diabetes, or those using immunosuppressant medications like chemotherapy.

• Sexually active women, as sexual intercourse can introduce bacteria into the bladder; urinating after intercourse may reduce infection risk.

• Women using a diaphragm for contraception.

• Men with an enlarged prostate, as prostatitis or urethral obstruction can cause incomplete bladder emptying, raising infection risk, particularly in older men.

Note: Males are generally less prone to UTIs due to their longer urethra and a drier environment at the urethral opening. Prostatic fluid also possesses antibacterial properties.

Acute Pyelonephritis

Acute pyelonephritis is marked by sudden inflammation of the kidney’s parenchyma (core tissue) and pelvis, potentially affecting one or both kidneys. It often arises from untreated bacterial cystitis and may be linked to pregnancy, urinary bladder trauma, or urinary obstruction.

Causative Agents of Pyelonephritis

• Klebsiella pneumoniae

• Proteus

• Escherichia coli and Enterococcus faecalis

• Staphylococcus albus and Staphylococcus epidermidis

• Pseudomonas

Clinical Manifestations of Pyelonephritis

• Sudden pain in one or both loins, radiating to the iliac fossa and suprapubic area.

• Dysuria

• Frequent passage of small urine volumes (scalded and cloudy).

• Strangury: a painful urge to urinate despite an empty bladder.

• Fever (38-40 degrees Celsius) with chills.

• Nausea and vomiting.

• Tenderness over the renal angle with muscle guarding.

• Elevated white blood cell count.

• Presence of protein, pus, and significant bacterial growth in urine.

• Diarrhea and convulsions, particularly in children.

Note: Untreated pyelonephritis can progress to renal failure.

Differential Diagnoses for Pyelonephritis

• Appendicitis

• Salpingitis

• Cholecystitis

Investigative Procedures for Pyelonephritis

• Urine microscopy to detect pus cells, microorganisms, and proteins (using midstream urine).

• Intravenous urography to exclude renal abscesses.

• Blood tests for differential leukocyte count (DLC) and total leukocyte count (TLC), revealing leukocytosis with neutrophilia and elevated erythrocyte sedimentation rate (ESR).

• Ultrasound scans to identify urinary tract obstructions.

• Blood tests to assess urea and electrolyte levels.

Management Strategies for Pyelonephritis

1. Ensure complete bed rest.

2. Encourage adequate fluid intake (around 3 liters or at least 8 glasses daily).

3. Monitor fluid input and urinary output to evaluate kidney function.

4. Administer anti-inflammatory therapy (e.g., NSAIDs) and antiemetics.

   • Intravenous ampicillin 1g every 4-6 hours for 14 days, combined with intravenous or intramuscular gentamicin 2.5mg/kg every 8 hours for 7 days.

   • Alternatively, cotrimoxazole and aminoglycosides may be effective.

   • Another option is oral amoxicillin 500mg three times daily for 10-14 days.

5. Maintain perianal hygiene and promote complete bladder emptying.

6. Conduct daily weight measurements to monitor hydration status and identify any unusual weight gain.

Chronic Pyelonephritis

Chronic pyelonephritis is associated with vesicoureteral reflux, where urine flows back from the bladder to the ureters, facilitating the spread of infection to the kidneys. Also termed reflux nephropathy, this condition can cause progressive damage to renal papillae and collecting ducts, potentially leading to renal failure and hypertension. Congenital abnormalities in ureter insertion into the bladder can predispose individuals to this condition. It often results in kidney shrinkage, scarring, and clubbing of the calyces. Clinical features may include bacteriuria, hypertension, flank tenderness, septic shock, dizziness, fainting, and indicators of renal insufficiency.