Chapter 52 Flashcards
Week 2
UTIs Epidemiology
UTIs are the most common bacterial infection, affecting 150 million people worldwide annually (Flores-Mireles et al., 2015).
21.3% of these encounters occur in emergency departments
In the U.S., UTIs cost approximately $3.5 billion annually
Women have a 50%-60% lifetime risk, peaking during years of sexual activity
Men have a 13.6% lifetime risk, often related to urinary tract obstructions like benign prostatic hyperplasia (BPH)
In children, 7.8% of girls and 1.7% of boys have a UTI by age 7, increasing to 11.3% and 3.6%, respectively, by age 16.
Uncircumcised infant boys have a 10-12 times higher UTI risk in the first 6 months
Vesicoureteral reflux, constipation, and bladder dysfunction increase UTI risk in children
UTI Complications
Most patients with UTIs do not experience long-term complications unless they have comorbid conditions like vesicoureteral reflux, renal stones, neurogenic bladder, diabetes, or obstruction.
UTI Pathophysiology
UTIs result from a complex interaction between host and microbial factors.
Protective mechanisms of the genitourinary tract include:
Periodic washout by voiding
Antibacterial properties of bladder epithelium
Low pH and high osmolality of urine
Competent urethral valve preventing backflow
UTI Risk Factors
Pregnancy, genetic factors, estrogen deficiency, residual urine, lack of circumcision, and BPH.
Fecal and urinary incontinence, lack of estrogen, immunocompromised states, and urinary instrumentation.
UTI Behavioral Factors
Higher risk in sexually active women due to factors like urethral trauma and residual urine.
Controversial factors include resisting the urge to void and increased fluid intake.
No strong evidence linking UTI risk to wiping direction, oral contraceptives, tampons, bubble baths, or douching.
UTI Inflammatory Response
Infection triggers an inflammatory response causing urgency, frequency, and pain.
Prostaglandins increase vascular permeability, potentially causing hematuria.
UTI Microbial Factors
Pathogens include gram-negative and gram-positive bacteria and fungi.
Escherichia coli is the most common cause, aided by fimbriae allowing attachment to bladder mucosa.
Some bacteria can tolerate urine’s low pH.
UTI Diagnosis
Based on symptoms and lab data and Screening recommendations
Based on symptoms and lab data:
Common symptoms: dysuria, urgency, frequency, hematuria, incontinence.
Urethral discharge in men often indicates STIs rather than UTIs.
Urinalysis: leukocyte esterase or pyuria, presence of bacteria, positive dipstick for nitrates.
Quantitative urine cultures: most reliable but expensive and time-consuming.
Screening Recommendations
Pregnant women should be screened for bacteriuria early in pregnancy.
USPSTF does not recommend screening for asymptomatic bacteriuria in men or nonpregnant women.
Symptoms by Age (Neonate)
Neonate: failure to thrive, irritability, fever, hypothermia, sepsis, jaundice, vomiting, acidosis.
Symptom by Age (Infant and Preschool/School age)
Crying on urination, foul-smelling urine, altered urination patterns, irritability, vomiting, diarrhea, failure to thrive.
hematuria, dysuria, frequency.
Abdominal pain, urgency, hesitancy, enuresis, incontinence.
Symptom by Age (Adult)
dysuria, frequency, urgency, hematuria, incontinence, suprapubic pain, low back pain.
Older adult: same as adult symptoms.
UTI Management
First-line antibiotics: nitrofurantoin, trimethoprim/sulfamethoxazole, fosfomycin.
Consider local resistance patterns when prescribing.
Cranberry products may help prevent recurrent UTIs.
Symptomatic relief: phenazopyridine (an AZO Dye) for urinary analgesic effects the urinary mucosa.
UTI Goals of Treatment
Primary Goal: Eradication of the causative organism.
Other Goals: Relief of symptoms and prevention of recurrent infections.
UTI Rational Drug Selection
Focus: Appropriate selection and use of drugs to treat both upper and lower urinary tract infections (UTIs).
UTI Common Organisms:
E. coli is predominant, but others like Klebsiella, Proteus, and Citrobacter also contribute.
UTI Increasing Resistance:
Fluoroquinolone-resistant gram-negative bacilli, methicillin-resistant Staphylococcus aureus (MRSA), extended spectrum beta-lactamase (ESBL)–producing bacteria, and others are on the rise.
First-line Treatment for Uncomplicated UTI:
Nitrofurantoin
Trimethoprim/sulfamethoxazole (TMP/SMZ)
Fosfomycin
Fluoroquinolones and Cephalosporins:
Not recommended due to resistance and adverse effects.
Amoxicillin and Ampicillin: High resistance levels.
First-Generation Cephalosporins (Cephalexin):
Efficacy varies with local resistance patterns.
Phenazopyridine: Used as a urinary analgesic for severe symptoms.
Complicated UTI or Comorbid Conditions
Longer Treatment Protocols: 5 to 7 days, guided by urine culture.
STI Complications: Doxycycline or Azithromycin for Chlamydia trachomatis; Ceftriaxone for Neisseria gonorrhoeae.
Upper UTIs (e.g., Pyelonephritis):
First-line: Ciprofloxacin or Levofloxacin.
Alternatives: TMP/SMZ if susceptibility is known.
Prophylaxis
Indications: Recurrent symptomatic UTIs.
Regimen: Continuous or postcoital prophylaxis. Options include TMP/SMZ, TMP, Nitrofurantoin, Cephalexin, Fosfomycin, and methenamine
