Urinary Tract Infections (UTI) are the most common bacterial infection (Foxman, 2003). Since UTIs are not reportable illnesses under the Centers for Disease Control’s National Notifiable Conditions database, their incidence and prevalence are not precisely known, although it is estimated that UTIs result in at least seven million office visits a year and over one hundred thousand hospitalizations each year (Foxman, 2003). Women are significantly more likely to develop an UTI due to the anatomical differences between the male and female urinary tract (Foxman, 2003). In men and women, most nosocomial UTI are catheter-associated (Foxman, 2003). Patients with compromised immune systems, urinary system abnormalities, diabetes, and the elderly are also at a higher risk for acquiring an UTI (Foxman, 2003). Sexual intercourse is also associated with increased UTI risk (Foxman, 2003). It is estimated that the costs associated with UTI exceed 1.6 billion dollars a year in the United States.
Urinary Tract infections include several separate and distinct clinical conditions including acute uncomplicated cystitis, recurrent cystitis, asymptomatic bateriuria (ASB), catheter-associated ASB, catheter associated UTI, pyelonephritis, and prostatitis (Gupta, Grigoryan ; Trautner, 2017). In women, 90% of all acute cystitis and pyelonephritis infections are caused by Escherichia coli infection (Gupta, Grigoryan ; Trautner, 2017). In a minority of cases, another coliform such as Klebsiella or Proteus may be the causative pathogen (Gupta, Grigoryan ; Trautner, 2017). Nosocomial catheter-associated infections are still predominately caused by E. coli, but other common nosocomial pathogens are found such as Enterobacter and Pseudomonas (Gupta, Grigoryan ; Trautner, 2017). The most common symptoms associated with UTI are hematuria, dysuria, and costovertebral angle tenderness (Gupta, Grigoryan ; Trautner, 2017). In women, presence or absence of vaginal discharge and vaginal odor or itching aids in the differential diagnosis, as these symptoms are associated with other conditions such as STDs and not present with UTIs (Gupta, Grigoryan ; Trautner, 2017). Uncomplicated cystitis in women is frequently diagnosed and treated clinically without urine culture, but in men, pregnant women, and where catheter-associated infections are suspected, a urine culture to determine the specific pathogen and antibiotic sensitivities is warranted (Gupta, Grigoryan ; Trautner, 2017). Urine samples captured mid-stream provide the highest probability of successful culture, but because of variations in handling and capture, urine cultures are not always definitive even where 105 CFU of a pathogen are detected. (Gupta, Grigoryan ; Trautner, 2017).
First-line antibiotics for UTI include Nitrofurantoin Monohydrate, Trimethoprim–Sulfamethoxazole (Bactrim), and Fosfomycin Trometamol (Gupta, Grigoryan ; Trautner, 2017). Secondary options include Beta-lactams and Fluoroquinolones (Gupta, Grigoryan ; Trautner, 2017). It is of note that Fluoroquinolones, which have excellent activity against gram-negative bacteria like E. coli and good bioavailability in the urinary tract, have been relegated to last-resort treatment options due to the increasing prevalence of antibiotic resistance (Gupta, Grigoryan ; Trautner, 2017). Patient compliance with treatment in critical, and the usual problems associated with courses of antibiotics such as early termination of therapy due to the disappearance of symptomology or the development of side effects such as diarrhea are common (Gupta, Grigoryan ; Trautner, 2017). Treatment of refractory infections depends on a number of factors such as comorbidities, the locations of the infection, and whether IV administration of antibiotics is required due to the failure of oral antibiotics to clear the infection (Gupta, Grigoryan ; Trautner, 2017). Complicated infections or infections that do not respond to standard therapy may require consultation with a specialist (Gupta, Grigoryan ; Trautner, 2017).
Foxman, B. (2003). Epidemiology of urinary tract infections: incidence, morbidity, and economic costs. Disease-A-Month, 49(2), 53-70.
Gupta, K. Grigoryan, L. ; Trautner, B. (2017). Urinary Tract Infection. Annals of Internal Medicine, 167(7), ITC49-ITC64.