• Painful or inflammatory condition affecting the prostate gland with or without bacterial etiology, often characterized by urogenital pain, voiding symptoms, and/or sexual dysfunction
  • National Institutes of Health’s (NIH) classifications:
    • Class I: acute bacterial prostatitis: symptomatic with fever, perineal pain, dysuria, and obstructive symptoms; polymorphonuclear leukocytes (PMNL) and bacteria in urine
    • Class II: chronic bacterial prostatitis: symptomatic chronic or recurrent bacterial infection with pain and voiding disturbances; PMNL and bacteria in expressed prostatic secretions (EPS), or urine after prostate massage, or in semen
    • Class III: chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS)
      • Inflammatory (subtype IIIA): chronic symptoms with PMNL in EPS/urine after prostate massage or in semen
      • Noninflammatory (subtype IIIB): chronic symptoms without presence of PMNL in EPS/urine after prostate massage or in semen
    • Class IV: asymptomatic inflammatory prostatitis: incidental finding during prostate biopsy; presence of PMNL and/or bacteria in EPS/urine after prostatic massage or in semen
  • System(s) affected: genitourinary, renal, reproductive



  • 2 million cases annually in the United States, with bimodal distribution: 20 to 40 and >60 years old
  • CD is more common after 50 years.
  • Bacterial prostatitis is more frequent in HIV.


  • Affects approximately 16%, up to 10% of those are acute bacterial prostatitis
  • Accounts for 8% of visits to urologists and 1% of visits to primary care physicians

Etiology and Pathophysiology

  • Acute bacterial prostatitis (NIH class I)
    • Most likely from ascending urethral infection with intraprostatic reflux of infected urine into prostatic ducts, often associated with cystitis
    • Can occur after instrumentation of prostate
    • Usually, gram-negative bacteria (Escherichia coli [most common]; Proteus, Klebsiella, Serratia, and Enterobacter species; Pseudomonas aeruginosa); Rarely, gram-positive (Staphylococcus aureus, Streptococcus, and Enterococcus spp.)
    • Staphylococcal prostatitis warrants evaluation for hematogenous spread (endovascular).
    • Atypical bacteria include Chlamydia trachomatis, Trichomonas vaginalis, Ureaplasma urealyticum, Mycobacterium tuberculosis and fungal etiologies in immunocompromised hosts.
    • Consider Neisseria gonorrhoeae or C. trachomatis in sexually active men aged <35 years.
  • Chronic bacterial prostatitis (NIH class II)
    • Similar pathogens as NIH class I
    • Often recurrent episodes of same organism
    • Progression from acute to CP is poorly understood.
  • CP/CPPS (NIH class III): most common
    • Unclear etiology
    • Inciting agent may cause inflammation or neurologic damage around the prostate and leads to pelvic floor neuromuscular and/or neuropathic pain.
    • No correlation between histologic inflammation of prostate and presence or absence of symptoms
    • Patients with chronic inflammation on histology have shorter time to symptomatic progression.

Risk Factors

  • Urinary tract infections (including STIs)
  • HIV infection
  • Prostatic calculi
  • Urethral stricture
  • Urinary catheterization: indwelling and intermittent
  • Genitourinary instrumentation: prostate biopsy (especially with prior quinolone intake), transurethral resection of the prostate (TURP), cystoscopy
  • Urinary retention
  • Benign prostatic hyperplasia
  • Unprotected sexual intercourse
  • Prostate cancer

General Prevention

  • Antibiotic prophylaxis for genitourinary instrumentation and prostatic biopsy
  • Increased physical activity associated with reduced risk for CP/CPPS

Commonly Associated Conditions

  • Benign prostatic hyperplasia, cystitis, urethritis
  • Sexual dysfunction (erectile dysfunction, premature ejaculation)

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