Free Online CME
take the web survey

Published: November 2013

Acute and Chronic Bacterial Cystitis

Joseph B. Abdelmalak

Jeannette M. Potts

Print this Content

Urinary tract infections (UTIs) are the most common nosocomial infections. They account for more than 7 million physician visits and over 1 million hospital admissions in the United States each year.1, 2 They are the most common bacterial infection in older adults and the most frequent source of bacteremia.3, 4 UTIs are second in seriousness only to respiratory infections.

Back to Top

Definition

The term uncomplicated urinary tract infection refers to the invasion of a structurally and functionally normal urinary tract by a nonresident infectious organism. Complicated UTI refers to the occurrence of infection in most men and in patients with an abnormal structural or functional urinary tract, or both (Box 1).

Box 1 Functional and Structural Abnormalities of the Genitourinary Tract
Functional Abnormalities
Vesicoureteral reflux
Neurogenic bladder
Obstruction
Congenital Abnormalities
Pelvic-ureteric obstruction
Ureteric and urethral strictures
Urolithiasis
Bladder diverticuli
Tumors
Foreign Bodies
Indwelling catheters
Other
Diabetes mellitus
Renal failure
Urinary diversions
Urinary instrumentation

Back to Top

Prevalence and Risk Factors

In 1995, the estimate for the United States put the direct cost of community-acquired UTIs at $659 million and indirect costs, through lost productivity, at $936 million.5-8 The UTI incidence ratio in middle-aged women to men is 30 : 1; however, during later decades of life, the ratio of infection in women to men with bacteriuria progressively decreases.9 Women are especially susceptible to cystitis for reasons that are poorly understood. One factor may be that a woman’s urethra is short, allowing bacteria quick access to the bladder. Also, a woman’s urethral opening is near sources of bacteria from the anus and vagina. For many women, sexual intercourse seems to trigger an infection, although the reasons for this linkage are unclear.10 Estimates have suggested that about one third of women will have at least one episode of UTI requiring antibiotic therapy by the time they are 24 years old, and over a lifetime 50% will have had at least one UTI.5-7 Hormonally induced changes in the vaginal flora associated with menopause are responsible for its higher prevalence in older women.11

Back to Top

Pathogenesis

The infection spreads to the urinary tract through an ascending route of fecal flora, from the fecal reservoir through the urethra into the bladder, particularly in patients with intermittent or indwelling catheters; hematogenous dissemination, secondary to Staphylococcus aureus bacteremia; or by direct extension from adjacent organs via the lymphatic system, as in the case of retroperitoneal abscesses or severe bowel obstruction. In women, colonization of the mucosa of the vaginal introitus is an essential step in the pathogenesis of UTIs.

Some people are more likely to get UTIs than others because of host factors or urothelial mucosal adherence to the mucopolysaccharide lining.12 Any abnormality of the urinary tract that interferes with the drainage of urine (e.g., kidney stones or an enlarged prostate) sets the stage for an infection, as well as foreign bodies in the bladder, such as catheters and tubes (see Box 1). Diabetes and other immunocompromised patients are at higher risk for a UTI and its complications. Sexual intercourse10 and women’s use of a diaphragm13 have also been linked to an increased risk of cystitis. Pregnancy does not increase the risk of cystitis; however, it increases the risk of pyelonephritis if UTI occurs.

Back to Top

Urinary Pathogens

Escherichia coli is the most common infecting organism in patients with uncomplicated UTIs.14 It causes 85% of community-acquired infections and approximately 50% of nosocomial infections. Other gram-negative microorganisms causing UTIs include Proteus, Klebsiella, Citrobacter, Enterobacter, and Pseudomonas spp. Gram-positive pathogens such as Enterococcus fecalis, Staphylococcus saprophyticus, and group B streptococci can also infect the urinary tract. Anaerobic microorganisms are frequently encountered in suppurative infections of the genitourinary tract (e.g., periurethral abscess, Fournier’s gangrene).

Back to Top

Signs and Symptoms

Cystitis may be asymptomatic. However, some patients report incontinence, a general lack of well-being, or both.15 Cystitis clinically manifests as irritative voiding symptoms that include frequency, dysuria, urgency, suprapubic or lower abdominal pain, and incontinence. In men, urinary retention should be ruled out, because it is frequently associated with cystitis and possible prostatitis. The manifestations of UTIs in older adults may include confusion, lethargy, anorexia, and incontinence.

Back to Top

Diagnosis

Physical examination, including a pelvic examination, should be carried out in women with lower urinary tract symptoms to exclude gynecologic, neurologic, or colorectal disorders. Physicians should also maintain a high index of suspicion for underlying sexually transmitted disease (STD). Up to 50% of women presenting to an emergency department for symptoms of cystitis were found to have positive STD cultures.16

Urine samples are collected for urinalysis in a sterile container through urethral catheterization, especially in women, or by midstream voided urine after the genital area is washed to avoid contamination. The sample is then tested for bacteriuria, pyuria, and hematuria. Indirect dipstick tests are informative but less sensitive than microscopic examination of the urine. About one third of the women who have acute symptoms of cystitis have sterile urine or some other cause for the symptom.17 Many diseases of the urinary tract produce significant pyuria without bacteriuria, including staghorn calculi, tuberculosis, and infections caused by Chlamydia and Mycoplasma spp. Microscopic hematuria is found in 40% to 60% of cystitis patients.18 Associated gross hematuria should be evaluated further by imaging studies. Cystoscopy is indicated for those patients older than 50 years or who have other risk factors for concomitant diseases, such as nephrolithiasis or transitional cell carcinoma (e.g., smoking).

Whereas empirical therapies are acceptable for uncomplicated cystitis (Box 2), culture and sensitivity testing should be performed in all other cases. It should be noted that a large percentage of women with cystitis have been found to have STDs. Additional cultures for Neisseria gonorrhea, Chlamydia, Mycoplasma hominis, and Ureaplasma ureolyticus should be considered for women with recurrent lower urinary tract symptoms.

Box 2 Urinary Tract Infection (UTI) in Adults
Uncomplicated
Acute cystitis in women
Acute pyelonephritis in young healthy women
Complicated
Acute cystitis in men
Acute prostatitis
Chronic prostatitis
Acute pyelonephritis in men
UTI with pregnancy
UTI with gross hematuria
UTI associated with nephrolithiasis
UTI associated with neurogenic bladder
UTI in diabetic or immunocompromised patient
Recurrent UTI (>3 episodes per year)

Radiologic studies are unnecessary for the routine evaluation of patients with cystitis; however, they may be indicated to find the cause of complicated cases, in which UTIs are associated with urinary calculi, ureteral strictures, ureteral reflux, urinary tract tumors, and urinary tract diversions. The following studies may be useful:

  • Plain radiography of the abdomen for the detection of radiopaque calculi or abnormal renal contour
  • Intravenous pyelography for radiographic images of the bladder, kidneys, and ureters. An opaque dye visible on radiographic film is injected into the vein and a series of radiographs are taken. The films demonstrate the contour of the collecting system, which may reveal filling defects or obstruction.
  • Voiding cystourethrography to evaluate neurogenic bladder and urethral diverticulum and to exclude or define the extent of vesicoureteral reflux
  • Renal ultrasonography, through interpretation of echogenic patterns generated by sound waves, can detect the presence of hydronephrosis, tumors, pyonephrosis, calculi, or abscesses.
  • Computed tomography (CT), a more sensitive means of defining renal parenchyma, especially when used with intravenous contrast material. CT urograms have replaced intravenous pyelograms in the evaluation of the urinary tract and kidneys, particularly in the workup of hematuria. Spiral CT scanning without contrast is the most sensitive means of detecting calculi within the urinary collecting system and is the standard of care for the evaluation of acute flank pain.
  • Magnetic resonance imaging may be indicated for patients who require further evaluation for renal neoplasm, in whom IV contrast is contraindicated. It may also be necessary as the most sensitive modality for the detection of urethral diverticulum.
  • The urethra and bladder can be inspected quickly and safely by the use of cystoscopy with a local anesthetic in an office setting.

Back to Top

Treatment

Cystitis

For the general management of cystitis, the patient is advised to drink plenty of water, which helps cleanse the urinary tract of bacteria. Cranberry juice and vitamin C (ascorbic acid) supplements inhibit the growth of some bacteria by acidifying the urine. Avoiding coffee, alcohol, and spicy foods is also useful. A heating pad and pain relief medication are helpful for pain management.

Cystitis is treated with antibacterial drugs. The choice of drug and length of treatment depend on several factors (Box 3). The sensitivity test is especially useful for selecting the most effective drug.

Box 3 Factors Influencing Selection of Antimicrobial Agents for Treating Urinary Tract Infections
Patient Factors
History of drug allergy
Medical history (e.g., renal impairment, liver impairment)
Presence of urologic abnormalities
Drug Factors
Safety profile
Spectrum of activity
Route of administration
Costs
Type of Organism
Results of Gram staining
Results of special culture and sensitivity testing
Acute Cystitis

Patients who have symptoms of frequency, urgency, pyuria on microscopic examination, and no known functional or anatomic abnormality of the genitourinary tract may be presumed to have acute uncomplicated cystitis. Empirical therapy with a 3-day regimen of trimethoprim-sulfamethoxazole (TMP-SMX) or a fluoroquinolone without pretreatment culture and sensitivity testing is usually effective. Alternative regimens such as a fluoroquinolone, an oral third-generation cephalosporin, or nitrofurantoin (7-day regimen) may have a better result. Generally, for most female patients, a 3-day course seems warranted, because this demonstrates similar efficacy when compared with 7-day therapy, and with lower side effects and cost.19 Single-dose therapy usually results in lower rates of cure and more frequent recurrences.

Recurrent Cystitis

The most common cause of recurrent UTI in women is reinfection that may occur with varying intervals and different causative organisms. Reinfection in women does not require extensive urologic evaluation. Recurrent episodes of uncomplicated cystitis can be managed by several strategies. Behavioral therapy includes increasing fluid intake, urinating as soon as the need is felt, as well as immediately after intercourse, and changing the method of contraception (for users of a diaphragm or spermicide), because spermicidal jelly contains nonoxynol 9, which decreases vaginal lactobacillus colonization and increases bacterial adherence. Long-term antimicrobial prophylaxis,20 postcoital prophylaxes with a single-dose antibiotic,21 or short-course (1- or 2-day) antibiotics for each symptomatic episode is recommended. For postmenopausal women, the use of vaginal estrogen cream may prove an effective preventive measure.11 Patients with bacterial persistence should be evaluated thoroughly to exclude potential structural or functional abnormalities.

Prostatitis

Prostate infections are more challenging to cure because of the altered microenvironment of the inflamed tissue, which may affect antibiotic efficacy. Therefore, men with acute bacterial prostatitis often need long-term treatment (≥30 days) with a carefully selected antibiotic. Severely ill patients need hospitalization and parenteral antimicrobial agents, such as an aminoglycoside-penicillin combination, until culture and susceptibility results provide guidance for alternative, specific antibiotic regimens. In men with urinary retention, a urethral or suprapubic catheter is necessary. Suprapubic catheterization is preferable to decrease the risk of prostatic abscesses. Mild and moderate cases respond well to fluoroquinolones or TMP-SMX, both of which have a cure rate of 60% to 90%.22 Chronic bacterial prostatitis may manifest as episodes of recurrent bacteriuria with the same organism between asymptomatic periods. Episodic treatment may be prescribed using the agents mentioned and, in select patients, may be self administered as needed. Daily suppressive therapy should be considered in men with frequent cystitis if other causes are excluded, and the culpable organism is localized to the prostate, using the Meares-Stamey technique.23

Back to Top

Differential Diagnosis

When evaluating patients with LUTS, it is important to consider gynecologic and colorectal diagnoses as well. STDs in either gender may manifest as lower urinary tract symptoms (LUTS), with or without fever. Female patients, especially those presenting with severe symptoms and pain, should be screened for pregnancy, because complications such as ectopic pregnancy or abortion should be ruled out. Chronic appendicitis and sigmoid diverticulitis may be confused with an UTI. We have encountered several patients referred for evaluation of persistent or recurrent UTI or prostatitis, in whom diverticulitis (and, even rarer, chronic appendicitis) was proven to be the cause of their symptoms.

Sexually Transmitted Diseases

Special cultures are needed to diagnose these infections. Antibiotic therapy should be prescribed accordingly. Longer treatment with tetracycline, doxycycline, or any drug appropriate for the treatment of Mycoplasma hominis and Ureaplasma urealyticum is recommended.24 The patient’s sexual partner must be treated simultaneously.

Back to Top

Considerations in Special Populations

Catheter-Related Infections

Catheterization for longer than 2 weeks is usually associated with bacteriuria. Prophylactic antimicrobial therapy for cystitis during short-term, indwelling, urethral catheterization is not recommended. Symptomatic UTIs in older adults should be treated. Careful consideration should be given to antimicrobial choice and meticulous monitoring of drug levels in this patient population, because the older patient is more susceptible to harmful side effects of many antimicrobial agents. Short-term antimicrobial therapy (5-7 days) is indicated only for symptomatic episodes. In patients requiring long-term urinary catheterization, suprapubic catheter placement should be considered. In men, suprapubic catheterization is associated with decreased risk of meatal erosion or prostatitis. In the short term, suprapubic catheterization may be associated with a decreased risk of bacteriuria or UTI. Unfortunately, this difference is not associated with long-term catheterization.25

Funguria is a common finding in catheterized patients. Whereas most patients are asymptomatic, interventions should include change in catheter, elimination of unnecessary antimicrobials, and glycemic control. Although amphotericin B may be used for bladder irrigations, it is less effective and more expensive than oral fluconazole therapy, although the latter is a concern in patients with hepatic vulnerability.

Removal of an indwelling catheter should be prompt; whenever possible, intermittent self catheterization should be used for patients with transient or long-term urinary retention.

Asymptomatic Bacteriuria

Bacteriuria denotes the presence of bacteria in the urine, which may be symptomatic or asymptomatic. Treatment of asymptomatic bacteriuria is indicated for pregnant women and those requiring urologic surgery.26 Preoperative treatment reduces postoperative complications, including bacteremia.27

Cystitis and Pregnancy

Although the prevalence of bacteriuria identified by screening is no higher in pregnant than nonpregnant women, the presence of asymptomatic bacteriuria in a pregnant woman should be treated promptly.28 The gravid uterus causes physiologic alterations that increase the risk of pyelonephritis. Pyelonephritis has been associated with infant prematurity, low birth weight, perinatal mortality, and high blood pressure.29 The recommended regimen is 7-day treatment with ampicillin or nitrofurantoin.

Urinary Tract Infection and Renal Failure

When creatinine clearance is significantly impaired, antibiotic dosage should be decreased since the renal blood flow is decreased and the perfusion of antimicrobial agents into the renal tissue and urine is impaired. Ampicillin, TMP-SMX, and fluoroquinolones are all effective for the treatment of UTIs in uremic patients.30, 31 Nitrofurantoin and tetracyclines are contraindicated for the treatment of UTIs in uremic patients.

Back to Top

Prophylaxis

Antimicrobial prophylaxis is recommended to ensure the sterility of urine for those who appear susceptible to developing infections. These include immunocompromised patients, patients with heart disease, people with a prosthetic heart valve, and patients who are scheduled for a procedure such as cystoscopy. Oral or vaginal estrogen administered prophylactically to postmenopausal women also reduces the incidence of cystitis.26, 31

Back to Top

Summary

  • UTI is one of the most common health problems affecting people of all ages. It is the most common nosocomial bacterial infection in older adults. Women are especially prone to UTIs for reasons that are poorly understood.
  • Although prostatitis syndrome accounts for 25% of male office visits for genitourinary tract infections, only 5% are attributed to a bacterial cause.
  • Acute cystitis or pyelonephritis in adult patients should be considered uncomplicated if there are no known functional or anatomic abnormalities of the genitourinary tract. Most of these infections are caused by Escherichia coli.
  • Acute uncomplicated cystitis can be effectively treated with a 3-day course of TMP-SMX, but alternative regimens such as a fluoroquinolone, an oral third-generation cephalosporin, or nitrofurantoin (7-day regimen) may have a better result. For acute uncomplicated pyelonephritis, a 10- to 14-day regimen is recommended.
  • Sexually transmitted diseases, including those caused by Chlamydia, Mycoplasma hominis, and Ureaplasma urealyticum, should be considered potential culprits in sexually active patients.
  • Complicated UTIs require thorough evaluation and correction of the underlying abnormality to provide a cure and prevent recurrence.

Back to Top

Suggested Readings

  • Foxman B: Epidemiology of urinary tract infections: Incidence, morbidity and economic costs. Am J Med 2002;113(Suppl. 1A): 5S–13S.
  • Michota F: Indwelling Urinary Catheters: Infection and Complications. In Potts J (ed): Genitourinary Pain and Inflammation: Diagnosis and Management. Totowa, NJ, Humana Press, 2008.
  • Parsons CL, Schmidt JD: Control of recurrent lower urinary tract infection in the postmenopausal woman. J Urol 1982;128:1224–1226.
  • Potts JM, Ward AM, Rackley RR: Association of chronic urinary symptoms in women and Urea plasma urealyticum. Urology 2000;55:486–489.
  • Raz R, Stamm WE: A controlled trial of intravaginal estriol in postmenopausal women with recurrent urinary tract infections. N Engl J Med 1993;329:753–756.
  • Ronald A: The etiology of urinary tract infection: Traditional and emerging pathogens. Am J Med 2002;113:14S–19S.
  • Schaeffer AJ, Rajan N, Cao Q, et al: Host pathogenesis in urinary tract infections. Int J Antimicrob Agents 2001;17:245–251.
  • Stapleton A, Latham RH, Johnson C, Stamm WE: Postcoital antimicrobial prophylaxis for recurrent urinary tract infection. A randomized, double-blind, placebo-controlled trial. JAMA 1990;264:703–706.

Back to Top

References

  1. Patton JP, Nash DB, Abrutyn E: Urinary tract infection: Economic considerations. Med Clin North Am 1991;75:495–513.
  2. Haley RW, Culver DH, White JW, et al: The nationwide nosocomial infection rate: A new need for vital statistics. Am J Epidemiol 1985;121:159–167
  3. Mulholland SG: Urinary tract infection: Clin Geriatr Med 1990;6:43–53.
  4. Esposito AL, Gleckman RA, Cram S, et al: Community-acquired bacteremia in the elderly: Analysis of 100 consecutive episodes. J Am Geriatr Soc 1980;28:315–319.
  5. Foxman B: Epidemiology of urinary tract infections: Incidence, morbidity and economic costs. Am J Med 2002;113(Suppl 1A): 5S–13S.
  6. Ronald A: The etiology of urinary tract infection: Traditional and emerging pathogens. Am J Med 2002;113:14S–19S.
  7. Foxman B, Barlow R, d'Arcy H, et al: Urinary tract infection. Self-reported incidence and associated costs. Ann Epidemiol 2000;10:509–515.
  8. Foxman B, Gillespie B, Koopman J, et al: Risk factors for second urinary tract infection among college women. Am J Epidemiol 2000;151:194–205.
  9. Boscia JA, Kaye D: A symptomatic bacteriuria in the elderly. Infect Dis Clin North Am 1987;1:893–905.
  10. Strom BL, Collins M, West SL, et al: Sexual activity, contraceptive use, and other risk factors for symptomatic and asymptomatic bacteriuria: A case-control study. Ann Intern Med 1987;107:816–823.
  11. Raz R, Stamm WE: A controlled trial of intravaginal estriol in postmenopausal women with recurrent urinary tract infections. N Engl J Med 1993;329:753–756
  12. Schaeffer AJ, Rajan N, Cao Q, et al: Host pathogenesis in urinary tract infections. Int J Antimicrob Agents 2001;17:245–251.
  13. Fihn SD, Latham RH, Roberts P, et al: Association between diaphragm use and urinary tract infection. JAMA 1985;254:240–245.
  14. Johnson JR: Virulence factors in urinary tract infection. Clin Microbiol Rev 1991;4:80–128.
  15. Boseki JA, Caboose WD, Abrutyn E, et al: Lack of association between bacteriuria and symptoms in the elderly. Am J Med 1986;81:979–982.
  16. Berg E, Benson DM, Haraszkiewicz P, et al: High prevalence of sexually transmitted diseases in women with urinary infections. Acad Emerg Med 1996;3:1030–1034.
  17. Johnson JR, Stamm WE: Diagnosis and treatment of acute urinary tract infections. Infect Dis Clin North Am 1987;1:773–791.
  18. Stamm WE, Counts GW, Wagner KF, et al: Antimicrobial prophylaxis of recurrent urinary tract infections: A double-blind, placebo-controlled trial. Ann Intern Med 1980;92:770–775.
  19. Sheehan G. Harding GKM, Ronald AR: Advances in the treatment of urinary tract infection. Am J Med 1984;76:141–147.
  20. Harding GK, Ronald AR, Nicolle LE, et al: Long-term antimicrobial prophylaxis for recurrent urinary tract infection in women. Rev Infect Dis 1982;4:438–443.
  21. Stapleton A, Latham RH, Johnson C, Stamm WE: Postcoital antimicrobial prophylaxis for recurrent urinary tract infection. A randomized, double-blind, placebo-controlled trial. JAMA 1990;264:703–706.
  22. Meares EM Jr: Infection stones of prostate gland. Laboratory diagnosis and clinical management. Urology 1974;4:560–566.
  23. Meares EM, Stamey TA: Bacteriologic localization patterns in bacterial prostatitis and urethritis. Invest Urol 1968;5:492–518.
  24. Potts JM, Ward AM, Rackley RR: Association of chronic urinary symptoms in women and Urea plasma urealyticum. Urology 2000;55:486–489.
  25. Michota F: Indwelling Urinary Catheters: Infection and Complications. In Potts J (ed): Genitourinary Pain and Inflammation: Diagnosis and Management. Totowa, NJ: Humana Press, 2008.
  26. Zhanel GG, Harding GK, Guay DR: Asymptomatic bacteriuria. Which patient should be treated? Arch Intern Med 1990;150:1389–1396.
  27. Andriole VT, Patterson TF: Epidemiology, natural history, and management of urinary tract infections in pregnancy. Med Clin North Am 1991;75:359–373.
  28. Waltzer WC: The urinary tract in pregnancy. J Urol 1981;125:271–276.
  29. Bennett WM, Craven R: Urinary tract infections in patients with severe renal disease. Treatment with ampicillin and trimethoprim-sulfamethoxazole. JAMA 1976;236:946–948.
  30. Kunin CM, Craig WA, Uehling DT: Trimethoprim therapy for urinary tract infection. Long-term prophylaxis in a uremic patient. JAMA 1978;239:2588–2590.
  31. Parsons CL, Schmidt JD: Control of recurrent lower urinary tract infection in the postmenopausal woman. J Urol 1982;128:1224–1226.

Back to Top