Chapter 140_ Urinary Tract Infections_ Cystitis, Prostatitis, and Pyelonephritis.pdf

Healthy young adult women from college campuses or HMOs

Which patient population has comprised the majority of participants in UTI clinical research trials?

An infection somewhere along the urinary tract that produces clinical symptoms

What is the clinical definition of a urinary tract infection?

Invasion of the bladder by a new pathogen or a shift in the existing urinary bacteria's dynamic equilibrium with the host

What are the two primary mechanisms by which a UTI develops?

Local tissue injury and inflammation

What pathological outcome results from bacterial invasion or a shift in host-bacterial equilibrium in the urinary tract?

Asymptomatic bacteriuria

What term describes the presence of bacteria in the urine without associated clinical symptoms?

Pyuria

What term describes the presence of white blood cells in the urine?

Symptomatic infection confined to the bladder in a woman or man without a urinary catheter

What is the definition of an uncomplicated urinary tract infection?

Symptomatic infection extending beyond the bladder, such as pyelonephritis, prostatitis, bacteremia, or catheter-associated infection

What is the definition of a complicated urinary tract infection?

Symptomatic infection of the bladder

What is the definition of cystitis?

Symptomatic infection of the prostate

What is the definition of prostatitis?

Symptomatic infection of the kidneys

What is the definition of pyelonephritis?

Whether the infection extends beyond the bladder

What is the core distinguishing feature between complicated and uncomplicated UTI in updated clinical classification?

Outpatient management stability, presence of a sequestered/recalcitrant focus, and requirement for systemic/tissue drug levels

What three key clinical considerations guide the frontline diagnostic and therapeutic approach to UTI?

Acute bacterial prostatitis and chronic bacterial prostatitis

What are the two primary clinical categories of bacterial prostatitis?

Prolonged therapy with antimicrobials capable of penetrating prostate tissue

What pharmacological requirement is necessary when treating prostatitis?

Neisseria gonorrhoeae, Chlamydia trachomatis, and Mycoplasma genitalium

Which three pathogens account for the vast majority of urethritis cases?

Urethral pain, pruritus, or purulent discharge

Which specific clinical symptoms should prompt evaluation for sexually transmitted infections rather than a standard UTI?

Male infants

In which pediatric population is the incidence of UTI slightly higher during the neonatal period due to congenital anomalies?

Prostatic hypertrophy causing urinary obstruction

Why does the incidence of UTI in men over age 50 approach that seen in women?

Females

Which gender predominantly experiences UTIs between 1 year and ~50 years of age?

Urinary catheterization or anatomic abnormalities

In men under 50 years of age, true UTIs occur almost exclusively in what setting?

Approximately 5%

What is the estimated prevalence of asymptomatic bacteriuria in women between 20 and 40 years of age?

40% to 50%

What is the estimated prevalence of asymptomatic bacteriuria among elderly men and women?

Up to 80%

What percentage of women develop at least one UTI during their lifetime?

14%

What is the estimated lifetime prevalence of UTI among men in the United States?

20% to 30%

What percentage of women who experience an initial UTI will develop recurrent episodes?

Relapse

How is a UTI recurrence occurring within 2 weeks of initial therapy usually classified?

2.6 reinfections per year

What is the average annual number of reinfections in women with recurrent UTI?

New risk factor, sloughing of protective outer bladder epithelium, or antibiotic-induced flora disruption

What three factors contribute to the temporal clustering of recurrent UTI episodes?

Decreases

How does the likelihood of a UTI recurrence change as time elapses since the last infection?

Frequent sexual intercourse and spermicide use

What are the two most consistently documented risk factors for recurrent UTI?

First UTI before 15 years of age and maternal history of UTI

What two historical factors correlate with an increased risk of recurrent UTI in women?

Shared colonization of uropathogenic E. coli via vaginal and oral sex

How can a new sexual partner increase the risk of UTI in women?

Impeding urine outflow, introducing bacteria/nidus, and impairing local mucosal defenses

What are the three broad categories of risk factors for UTI?

The flushing action of normal urination

What is the principal host mechanism for controlling urinary bacterial populations and preventing bacterial ascent?

Congenital anomalies, cystoceles, pelvic-organ prolapse, overflow incontinence, and benign prostatic hypertrophy

Which anatomical or functional conditions cause urinary obstruction or retention predisposing to UTI?

No, men ≤45 years old can develop UTI without detectable anatomical abnormalities

Do all men who develop a UTI have underlying detectable urinary tract abnormalities?

Relative risk increases from 1.4 with weekly intercourse to 4.8 with intercourse five times weekly

How does the frequency of sexual intercourse affect the relative risk of cystitis?

Insertive rectal intercourse and lack of circumcision

Which two specific behavioral and anatomical factors increase UTI risk in men?

Colonization of the glans and prepuce by E. coli

Why does lack of circumcision increase the risk of UTI in males?

Intermittent or chronic urinary catheterization and nephrostomy tubes

Which urologic instruments dramatically increase bacterial entry into the urinary tract?

Stents and kidney stones

Which foreign bodies in the urinary tract act as persistent colonization sites and niduses for recurrent UTI?

Recent diaphragm or spermicide use and menopause

Which factors impair local mucosal defenses by irritating urogenital mucosa or disrupting lactobacilli?

Two- to threefold increase

How much higher is the prevalence of ASB and UTI in women with diabetes compared to non-diabetic women?

Longer duration of diabetes and reliance on insulin therapy

Which two clinical factors in diabetic patients further increase UTI risk?

SGLT-2 inhibitors

Which drug class carries an FDA safety warning for increased UTI risk due to glucosuria induction?

Bacterial ascent from the urethra to the bladder and up the ureters to the kidneys

What is the primary anatomical route by which most UTIs are established?

Less than 2%

What percentage of documented UTIs originate from hematogenous spread?

Normal voiding and innate host defense mechanisms

What host factors eliminate bacteria that enter the bladder following sexual intercourse?

Intracellular bacterial communities within bladder urothelial cells

What bacterial persistence phenomenon has been demonstrated in animal models and exfoliated human cells?

Staphylococcus aureus and Salmonella

Which two virulent pathogens isolated from urine culture strongly suggest preceding bacteremia and hematogenous spread?

Focal renal abscesses or pyelonephritis

What renal parenchymal lesions can result from hematogenous bacterial seeding?

Intestinal flora colonization of the vaginal introitus and periurethral area

What is the critical initial colonization step in the pathogenesis of female ascending UTI?

Nonoxynol-9

Which component of spermicide is toxic to protective vaginal lactobacilli?

Replacement of protective lactobacilli with colonizing Gram-negative bacteria due to vaginal atrophy

How does menopause alter vaginal microecology to increase UTI susceptibility?

Topical estrogens

Which hormonal formulation reduces recurrent UTI frequency in postmenopausal women without systemic effects?

Oral estrogens

Which estrogen route should NOT be used for UTI prevention due to systemic risks?

P fimbriae

Which E. coli surface adhesins interact with blood-group antigen P D-galactose-D-galactose receptors on renal cells?

Pyelonephritis and subsequent bloodstream invasion

In the pathogenesis of which upper tract UTI syndrome do P fimbriae play a major role?

Type 1 pilus

Which surface structure present on all E. coli strains binds to mannose on luminal bladder cells to initiate cystitis?

Mannose residues

What luminal bladder uroepithelial receptor component is bound by E. coli Type 1 pili?

Toxins, iron-acquisition systems, biofilm formation, and capsular polysaccharides

What four microbial factors beyond adhesins assist uropathogenic E. coli in bladder survival?

Does the patient have UTI vs ASB; is infection confined to the bladder or beyond; is it safe to delay empirical therapy

What three key questions shape the diagnostic approach when UTI is suspected?

Absence of localizing urinary symptoms or unexplained systemic symptoms in a patient with a positive culture

What clinical picture defines asymptomatic bacteriuria?

Incidental finding on screening urine culture

How is asymptomatic bacteriuria typically discovered in clinical practice?

Not sending urine cultures in asymptomatic patients except when pregnant or prior to urologic procedures

What is the core principle of diagnostic stewardship regarding ASB?

Fever

Which systemic sign is a primary feature distinguishing pyelonephritis from acute cystitis?

Low-grade fever with or without lower back or CVA pain

What are the characteristic symptoms of mild pyelonephritis?

High fever, rigors, nausea, vomiting, and flank pain

What are the hallmark clinical signs of severe pyelonephritis?

Sloughed renal papillae obstructing the ureter

What mechanism causes obstructive uropathy as a complication of pyelonephritis?

Sickle cell disease and analgesic nephropathy

In addition to severe pyelonephritis, what two conditions predispose to acute papillary necrosis?

A rapid rise in serum creatinine level

What laboratory finding provides the initial clue to bilateral acute papillary necrosis?

Emphysematous pyelonephritis

What severe gas-forming renal parenchymal infection represents an extreme complicated pyelonephritis variant?

Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium

What three major pathogens cause infectious urethritis?

Cervicitis, vaginitis, herpetic urethritis, interstitial cystitis, or noninfectious vulvovaginal irritation

What non-UTI conditions can cause dysuria in women?

Vaginal discharge

Which symptom in a female presenting with lower urinary tract symptoms strongly suggests an STI rather than a UTI?

Nitrite and leukocyte esterase

Which two chemical tests are evaluated on a point-of-care urine dipstick?

Red blood cell count and white blood cell count

Which cellular counts are quantified during microscopic urinalysis?

To rule out UTI when both nitrite and leukocyte esterase tests are negative

What is the primary clinical utility of point-of-care dipstick testing?

No, urine dipsticks lack sufficient sensitivity and screening must be done via urine culture

Can a negative urine dipstick rule out ASB in a pregnant patient?

Pyuria and bacteriuria are almost universally present in catheterized patients without indicating active UTI

Why are urine dipstick and urinalysis findings unreliable for diagnosing UTI in catheterized patients?

Neutrophils

Which host defense cells produce the leukocyte esterase detected on urine dipstick testing?

Nonantibiotic treatment with NSAIDs alone delays clinical response and predisposes to invasive infections

Why is symptomatic therapy with NSAIDs alone discouraged for true UTI?

Prolongs discomfort and carries a small increased risk of progression to pyelonephritis

What are the risks associated with delayed antibiotic prescription strategies for cystitis?

Avoiding unnecessary ASB treatment, avoiding unindicated urine cultures, and avoiding excessive treatment durations

What are three high-yield antimicrobial stewardship interventions in UTI management?

Greater than 20% resistance

What resistance rate to TMP-SMX, fluoroquinolones, and nitrofurantoin was observed among US ambulatory Enterobacterales isolates?

Approximately 6%

What percentage of ambulatory US Enterobacterales UTI isolates exhibit resistance to three or more antibiotic classes?

Approximately 9%

What percentage of ambulatory US Enterobacterales UTI isolates produce extended-spectrum β-lactamases?

Local antibiogram data

What resource should clinicians consult to guide local empirical antibiotic selection?

Selection and emergence of multidrug-resistant organisms resulting from antimicrobial exposure

How is "collateral damage" defined in the context of UTI treatment?

Prior resistant isolate, recent exposure to that agent, travel to high-resistance areas, catheters, and healthcare facility residence

What five factors increase a patient's risk of harboring a resistant uropathogen?

Fluoroquinolones

Which antibiotic class carries the greatest increase in resistance risk following recent exposure in the preceding year?

It does not decrease subsequent UTIs and may increase infection risk in renal transplant recipients

What impact does antibiotic treatment of ASB have on long-term UTI frequency?

Pregnant patients and patients scheduled for procedures causing urologic mucosal injury

What are the two mandatory clinical indications for screening and treating ASB?

Pyelonephritis, preterm delivery, and low birth weight

What three adverse outcomes are associated with untreated ASB in pregnancy?

Translocation of bacteria from urine to blood causing bacteremia

What complication can occur during invasive urologic procedures in patients with untreated ASB?

Urine culture obtained prior to the procedure

What diagnostic test should guide antibiotic selection for ASB in pregnant or preoperative patients?

Do not send a urine culture and do not administer antimicrobials

What is the recommended management for an asymptomatic patient undergoing catheter placement or removal?

Remote telephone-management algorithms

How can acute uncomplicated cystitis in healthy, low-risk women be managed safely?

TMP-SMX, nitrofurantoin, fosfomycin, and pivmecillinam

What are the four preferred empirical agents for acute uncomplicated cystitis?