What is the most common cause of upper Urinary Tract Infection (UTI) in women?

From the Guidelines

Escherichia coli is the most common cause of upper Urinary Tract Infection (UTI) in women.

Causes of Upper UTI

• In young healthy women, Escherichia coli accounts for more than 90% of APN cases 1.
• Other less common causes include gram-negative bacilli, gram-positive organisms, and candida, which are more common in men, elderly women, and urologically compromised and institutionalized patients 1.

Risk Factors

• Risk factors for cystitis predispose to APN and include sexual activity, new sexual partner, spermicide exposure, personal or maternal history of UTIs, genetic predisposition, and diabetes mellitus 1.
• Factors that disrupt urinary flow such as vesicoureteral reflux, congenital urinary tract anomalies, altered bladder function, pregnancy, renal calculi, or mechanical obstruction increase the risk of developing APN 1.

Diagnosis and Treatment

• Urine cultures yielding >10,000 colony-forming units of a uropathogen per milliliter of urine is the fundamental confirmatory diagnostic test for APN 1.
• Antibiotics are the primary treatment for APN, with the choice of antibiotic depending on the severity of the infection, the patient's underlying health, and the susceptibility of the causative organism 1.

From the Research

Causes of Upper Urinary Tract Infection (UTI) in Women

• The most common cause of upper Urinary Tract Infection (UTI) in women is Escherichia coli (E coli) 2, 3, 4, 5
• Other pathogens that can cause UTIs include Klebsiella, Enterococcus, Pseudomonas, Staphylococcus, and Candida species 3, 5
• The etiology of UTI can be affected by underlying host factors, such as age, diabetes, spinal cord injury, or catheterization, which can lead to a more diverse range of pathogens 5

Prevalence of UTI in Women

• UTIs are one of the most common infections afflicting women, with as many as 50% of women reporting having had at least one UTI in their lifetimes 2
• The annual incidence of UTIs is 12.1% among women and 3% among men 4
• Recurrent UTIs are common, occurring in 20% to 30% of women 4

Pathogenesis of UTI

• UTIs often accompany vaginal infections and are frequently caused by pathogens originating in the digestive tract 6
• The pathogenesis of UTI involves the adherence of uropathogenic bacteria to the epithelial cells of the urinary tract, leading to infection and inflammation 3