Patricia Lewandoski, MD
Akhil Das, MD, FACS
BASICS
DESCRIPTION
• A urinary tract infection (UTI) is a male is an inflammatory response of urothelium to bacterial invasion with associated bacteriuria and pyuria (1)
• Defined by source of infection:
– Cystitis: Infection of bladder; dysuria, frequency, urgency, suprapubic pain, hematuria.
– Isolated cystitis in men rare, usually associated with prostatitis or pyelonephritis
– Pyelonephritis: Infection of kidney; chills, fever, flank pain ± symptoms of cystitis
– Prostatitis infection or inflammation of prostate; acute or chronic; either bacterial or nonbacterial based on NIH classification (see Section I: “Prostatitis, General”)
– Urethritis: Infection of urethra
• Defined as uncomplicated or complicated
– Uncomplicated: Isolated infection or reinfection in a healthy young male with normal urinary tract; urethritis or prostatitis
– Complicated: Infection associated with:
Structurally abnormal urinary tract (eg, bladder outlet obstruction/BPH), or
Functionally abnormal urinary tract (eg, neurogenic bladder)
Impaired host defense (eg, immunosuppression/diabetes)
Increased bacterial virulence
• Most UTIs in men are complicated.
• Defined based on chronicity:
– Unresolved: UTI that has not responded to antimicrobial treatment
– Recurrent: UTI that occurs after complete resolution (proven by negative culture after complete antimicrobial course) of previous UTI
• Reinfection: A recurrent UTI from reintroduction of bacteria into previously sterilized urine
• Bacterial persistence: A recurrent UTI due to a source of bacterial colonization (eg, infected stone, prostate, or foreign body)
• Other definitions (and suggested therapies):
– Emphysematous cystitis/emphysematous pyelonephritis: Complicated UTIs associated with gas in bladder wall or renal parenchyma; typically found in diabetes; gas-forming organisms and obstruction (in pyelonephritis); treated with parenteral antimicrobials; pyelonephritis may require nephrectomy
– Xanthogranulomatous pyelonephritis:
Chronic renal infection associated with obstruction, nephrolithiasis; massively enlarged, nonfunctioning kidney; presenting signs of flank pain, fever, and persistent bacteriuria
• Asymptomatic bacteriuria in men:
– 102 CFU/mL of single organism from cath specimen or 105 CFU/mL from single clean catch in men without symptoms of UTI
– Treatment recommended only prior to urologic procedures (2)[C]
• Prophylaxis in those at risk (ie, spinal cord injury or other cause for indwelling catheter) is not recommended; treat only when symptomatic.
EPIDEMIOLOGY
Incidence
12.6/1000 person years (if prostatitis included as UTI) (3)[C]
Prevalence
• Increases with age to >10% in men aged >65 yr
• Asymptomatic bacteriuria in elderly men approaches 60–80%.
RISK FACTORS
• Risk factors for complicated UTI:
– Male gender
– Elderly
– Diseases: Diabetes mellitus; recent UTI, immunosupressive disease or diseases requiring the use of immunospsuppression such as steroids
– Recent antimicrobial use
– Indwelling urinary catheter
– Recent urologic intervention or hospital infection
– Urinary tract obstruction (eg, BPH, urethral stricture disease); urinary stasis
– Urinary calculi
– Uncircumcised
– Spinal cord injury
– Unprotected anal intercourse
– History of childhood UTI
Genetics
Certain individuals (including those with HLA-A3) prone to recurrent UTIs have increased epithelial cell receptivity for uropathogenic Escherichia coli.
PATHOPHYSIOLOGY
• UTI occurs via 1 of 3 routes (1):
– Ascending: Via inoculation of urethra/urethral catheter with bowel flora: Most common
– Hematogenous seeding of kidney
– Lymphatic spread
• Males are more resistant to UTI than females due to longer urethra, antibacterial nature of prostatic fluid, drier periurethral environment.
• UTIs occur as a result of interaction between host defense mechanisms and bacterial virulence:
– Inherent host defense mechanisms:
– Urinary flow helps decrease retrograde infection; conversely, residual urine/obstruction increases risk of infection
– Urine: Urea, pH, organic acids help prevent growth; glucose provides environment conducive for bacterial growth and increases risk of infection
– Bladder: Host recognition of bacteria, with innate immune response against infection; exfoliation of infected urothelial cells
– Infection of urinary tract involves attachment of bacterium to the host’s epithelium.
– Adherence of bacteria to urothelial cells necessary for infection; some virulent bacteria have type 1 pili (mediate attachment to cells); pyelonephritis bacteria contain P pili
• Common community-acquired uropathogens: E. coli (most common), Proteus, Klebsiella pneumonia, Enterococcus faecalis, Staphylococcus saprophyticus
• Common nosocomial uropathogens: E. coli, Klebsiella, Enterobacter, Citrobacter, Serratia, Pseudomonas, Enterococcus faecalis, Providencia, S. epidermidis
ASSOCIATED CONDITIONS
See “Risk Factors.”
GENERAL PREVENTION
Maintenance of low residual urine clearing any foreign bodies (catheters, stones)
DIAGNOSIS
HISTORY
• Assess for any of risk factors listed above.
• Workup of recurrent UTI, inquire about risk factors and obtain a complete and thorough culture history of involved bacteria, treatment course, and documented evidence of clearance of bacteria.
PHYSICAL EXAM
• Obtain vital signs to assess severity of infection, presence of systemic disease.
• Assess for suprapubic pain, flank pain, and urethral discharge and rectal exam for tenderness and fluctuance.
• Uncircumcised: May increase risk of infection
DIAGNOSTIC TESTS & INTERPRETATION
Lab
• Urine analysis: Quality of specimen grossly assessed by presence (poor) or absence (good) of squamous cells
• Microscopic analysis for bacteria: False-positive from foreskin contamination if poor-quality specimen; false-negative if 102–104 bacteria/mL (too few to be seen under slide)
• Dipstick: WBC must be present for infection but WBC without bacteriuria may be present with stones, indwelling stent, tuberculous infection
– Nitrite: Bacterial reduction of nitrate in urine
– Leukocyte esterase: Presence of WBC
– Sensitivity of nitrite and leukocyte esterase positivity varies greatly; does not replace microscopic analysis for bacteria
• Culture: Midstream clean catch: Reduce bacterial contamination of culture in uncircumcised men by retracting foreskin and cleansing
– 102–103 CFU/mL in dysuric male with pyuria is indicative of infection (clean catch).
• For lower UTI, consider localization studies (see Section I: “Prostatitis, General”).
Imaging
• Recommended in most men to rule out complicated infection, if not responding to therapy, in patients with rapid recurrent infection and found to have bacteria susceptible to antimicrobial used (i.e., persistence), when obstruction suspected
• CT urogram or MRI: Provide excellent detail, evidence of urinary tract abnormalities, stones, or foreign bodies, among others
Diagnostic Procedures/Surgery
• Cystoscopy: Same indications as listed under “Imaging”; allows direct visualization of bladder to assess for foreign body, ectopic ureters, diverticula, stones, or other abnormalities
• PVR: Should be considered in men with BPH, voiding dysfunction; high residual with stasis increases risk of infection
• Localization studies: Selective cultures from each kidney via ureteral catheterization and prostatic cultures are helpful in identifying source of bacterial persistence.
Pathologic Findings
N/A
DIFFERENTIAL DIAGNOSIS
• Urgency, frequency, dribbling, and dysuria can be symptoms of prostatitis.
• Prostatitis:
– NIH Class I: Acute bacterial prostatitis, sudden onset
– NIH Class II: Chronic bacterial prostatitis; Insidious onset, relapsing, recurrent UTI
• For cystitis: Interstitial cystitis vs. urethritis
• For pyelonephritis: Pancreatitis vs. appendicitis vs. diverticulitis vs. acute focal/multifocal nephritis
TREATMENT
GENERAL MEASURES
• Maintain adequate hydration/good hygiene.
• Remove urinary catheters as soon as possible to prevent catheter associated UTI
MEDICATION
First Line
• Antimicrobial therapy for UTI in men is extrapolated from data for treatment of women. (see Section I: “Prostatitis, General”)
• If severe infection or toxicity is present, CT should be obtained to rule out obstructive pyelonephritis; if found, decompression is critical.
• Common oral antimicrobials (1):
– Trimethoprim-sulfamethoxazole: Inexpensive, covers staphylococci, streptococci, and most gram-negatives except Pseudomonas
– Fluoroquinolones: More expensive (levofloxacin > ciprofloxacin), cover staphylococci and most gram-negatives including Pseudomonas
• Common parenteral antimicrobials:
– Ampicillin: Covers streptococci, enterococci, E. coli, Proteus; addition of β-lactamase inhibitor covers Klebsiella and Haemophilus; no pseudomonal coverage; good 1st-line IV drug
– Gentamicin: Staphylococci, most gram-negatives including Pseudomonas; augments ampicillin for coverage in pyelonephritis
• For cystitis (1)[C]:
– Take into account local resistance profiles
– No controlled trials; antimicrobials based on local resistance patterns, previous culture
– Further tailored to culture sensitivities
– Duration: For most men with complicated infections, treat for at least 10 days
• In complicated UTI, obtain culture during therapy and 1–2 wk after therapy is complete to document clearance.
– For uncomplicated UTI, longer-duration treatment (>7 days) has no association with a reduced risk for early or late recurrence compared to shorter treatment (≤7 days)
• For pyelonephritis (1)[C]:
– For men, pyelonephritis is a complicated UTI and outpatient therapy is initiated only after treatment of complicating factors is initiated.
– Renal/perirenal abscess: Suspected if indolent/recurrent fever >72 h and/or persistently positive culture despite therapy; CT when suspect; if small abscess antimicrobial treatment; if large (>3 cm) abscess or perinephric abscess: percutaneous drainage
• Outpatient therapy:
– Fluoroquinolone (7 days) is more effective than trimethoprim-sulfamethoxazole (14 days)
– Tailor antimicrobial to culture sensitivities.
– If no improvement, use IV therapy
• Inpatient therapy:
– IV fluoroquinolone or ampicillin + gentamicin or 3rd-generation cephalosporin
– Duration without bacteremia: 2–3 days IV then 10–14 days PO antimicrobial
– Duration with bacteremia: 7 days IV, then 10–14 days appropriate PO antimicrobial
• Repeat cultures on therapy and 10–14 days after completion of course should be negative; if positive, continue a 14-day specific regimen
Second Line
Abscesses in the upper urinary tract or prostate often require percutaneous drainage.
SURGERY/OTHER PROCEDURES
• As needed for cause of recurrent UTI, such as stone, foreign body, or enlarged prostate.
• Transurethral resection (TUR) (unroofing procedure) or percutaneous drain may be required for prostatic abscess.
ADDITIONAL TREATMENT
Radiation Therapy
N/A
Additional Therapies
N/A
Complementary & Alternative Therapies
Cranberry juice: No male evidence (4)[B]
ONGOING CARE
PROGNOSIS
When appropriate antimicrobial therapy is chosen, complicating factors are identified and treated, and close follow-up is achieved with documentation of clearance of infection, a good prognosis is expected.
COMPLICATIONS
• Sepsis
• Upper urinary tract infections with abscess formation can cause loss of renal function.
FOLLOW-UP
Patient Monitoring
Follow-up culture, post void resideual urine (PVR) and adassessment of lower urinary tract symptoms (LUTS)
Patient Resources
Urology Care Foundation: Urinary Tract Infection in Adults. http://www.urologyhealth.org/urology/index.cfm?article=47
REFERENCES
1. Schaeffer AJ, Schaeffer EM. Infections of the urinary tract. In: Wein AJ, et al., eds. Campbell-Walsh Urology, 10th ed. Philadelphia, PA: Saunders; 2011.
2. Nicolle LE, Bradley S, Colgan R, et al. Infectious Diseases Society of America guidelines for the diagnosis and treatment of asymptomatic bacteriuria in adults. Clin Infect Dis. 2005;40:643.
3. Ruben FL, Dearwater SR, Norden CW, et al. Clinical infections in the noninstitutionalized geriatric age group: Methods utilized and incidence of infections. The Pittsburgh Good Health Study. Am J Epidemiol. 1995;141(2):145.
4. Drekonja DM, Rector TS, Cutting A, et al. Urinary Tract Infection in Male Veterans: Treatment Patterns and Outcomes. JAMA Intern Med. 2013;173(1):62–68.
ADDITIONAL READING
EAU Guidelines on Urological Infections. http://www.uroweb.org/gls/pdf/18_Urological%20infections_LR.pdf
See Also (Topic, Algorithm, Media)
• Prostatitis, Acute, Bacterial (NIH 1)
• Prostatitis, Chronic, Nonbacterial, Noninflammatory (NIH CP/CPPS III B)
• Prostatitis, Chronic, Bacterial, (NIH II)
• Prostatitis, Chronic, Nonbacterial, Inflammatory (NIH CP/CPPS III A)
• Prostatitis, General
• Pyelonephritis
• Urethritis, Acute Male
• Urinary Tract Infection (UTI), Complicated, Adult
• Urinary Tract Infection (UTI), Pediatric
CODES
ICD9
• 590.80 Pyelonephritis, unspecified
• 595.9 Cystitis, unspecified
• 599.0 Urinary tract infection, site not specified
ICD10
• N12 Tubulo-interstitial nephritis, not spcf as acute or chronic
• N30.90 Cystitis, unspecified without hematuria
• N39.0 Urinary tract infection, site not specified
CLINICAL/SURGICAL PEARLS
• Most UTIs in men are considered complicated and require a longer course of antibiotics.
• UTI-related prostatitis requires a minimal of 7 days of treatment.