Chapter 23: Urinary Tract Infections

Urinary tract infections (UTIs) are among the most common bacterial infections encountered in medicine. Accurately estimating incidence is difficult because UTIs are not reportable, but estimates range from 650,000 to 7 million office visits per year.

A UTI is defined by urologists as any infection involving the urothelium, which includes urethral, bladder, prostate, and kidney infections. Some of these are diseases that have been clearly characterized (eg, cystitis and pyelonephritis), whereas others (eg, urethral and prostate infections) are not as well understood or described.

The terms simple UTI and uncomplicated UTI are often used to refer to cystitis. In this chapter UTI is used to refer to any infection of the urinary tract, and cystitis is used to specify a bladder infection. The generic term complicated UTI is often used to refer to cystitis occurring in a person with preexisting metabolic, immunologic, or urologic abnormalities, including kidney stones, diabetes, and AIDS, or caused by multidrug resistant organisms.

Asymptomatic bacteriuria, uncomplicated cystitis, complicated cystitis, two urethral syndromes, four prostatitis syndromes, and pyelonephritis are discussed in this chapter. Although separated into different diagnoses, differentiating among syndromes and deciding treatment is left to the clinician’s discretion.

Antibiotic resistance is a topic that has been left mostly to the reader. General recommendations about specific antibiotics are inappropriate, given that antibiotic resistance differs from location to location. It is the responsibility of individual physicians to be familiar with local antibiotic resistances, and to determine the best first-line therapies for their practice. Always keep in mind that antibiotic use breeds resistance, and try to keep first-line drugs as simple and narrow-spectrum as possible.

General Considerations

Asymptomatic bacteriuria is defined separately for men, women, and the type of specimen. For women, clean-catch voided specimens on two separate occasions must contain >10⁵ CFU/mL of the same bacterial strain, or one catheterized specimen must contain >10² CFU/mL of bacteria. For men, a single clean-catch specimen with >10⁵ CFU/mL of bacteria or one catheterized specimen with >10² CFU/mL of bacteria suffices for the diagnosis. By definition, the patient must be asymptomatic, that is, should not be experiencing dysuria, suprapubic pain, fever, urgency, frequency, or incontinence. Screening for bacteriuria does not need to be done in young, healthy, nonpregnant women; elderly healthy or institutionalized men or women; diabetic women; persons with spinal cord injury; or catheterized patients while the catheter remains in place. Pregnant women are now the only group that should be routinely screened and treated for asymptomatic bacteriuria. There are multiple guidelines recommending screening of this group of patients. Screening should occur between 12 and 16 weeks’ gestation. The incidence is approximately 5–10% of pregnant women. There are numerous studies showing an association between asymptomatic bacteriuria and premature birth, low birth weight, and a high incidence of pyelonephritis. In the United States, screening is usually done by urine culture because dipstick screening can miss patients without pyuria or with unusual organisms.

Treatment

Treatment should be guided by local rates of resistance, keeping in mind safety of the antibiotic in pregnancy. The usual first-line treatment in the absence of significant resistance or penicillin allergy is a 7-day course of amoxicillin. Nitrofurantoin or a cephalosporin is suggested for penicillin-allergic pregnant patients, again for 7 days.

General Considerations

Acute, uncomplicated cystitis is most common in women. Approximately one-third of all women have experienced at least one episode of cystitis by the age of 24 years, and nearly half will experience at least one episode during their lifetime. When a young woman presents to a health care provider with one or more symptoms, her probability of UTI is approximately 50%. Young women’s risk factors include sexual activity, use of spermicidal condoms or diaphragm, and genetic factors such as blood type or maternal history of recurrent cystitis. Healthy, noninstitutionalized older women can also experience recurrent cystitis. Risk factors among these women include changes in the perineal epithelium and vaginal microflora after menopause, incontinence, diabetes, and history of cystitis before menopause.

Although men can also suffer from cystitis, it is rare (annual incidence: <0.01% of men aged 21–50 years) in men aged <35 years who have normal urinary anatomy. Urethritis from sexually transmitted pathogens should always be considered in this age group, and prostatitis should always be ruled out in the older age group by a rectal examination. Any cystitis in a man is complicated, due to the presence of the prostate gland, and should be treated for 10–14 days to prevent a persistent prostatic infection.

Prevention

A. Young Women

Considering the frequency and morbidity of cystitis among young women, it is hardly surprising that the lay press and medical literature contain a host of ideas about how to prevent recurrent cystitis. These range from the suggestion that cotton underwear is “healthier” to wiping habits, voiding habits, and choice of beverage. Unfortunately, the vast majority of these preventive measures do not hold up to scientific study (Table 23-1).

Recent studies have shown no effect of back-to-front wiping, precoital voiding, tampon use, underwear fabric choice, or use of noncotton hose or tights. Behaviors that do appear to have an impact on frequency of cystitis in young women include sexual activity (four or more episodes per month in one study), delayed postcoital voiding, use of spermicidal condoms (several studies), use of unlubricated condoms (one study), use of diaphragms or cervical caps, and intake of cranberry juice.

It can be concluded from Table 23-1 that a few behaviorally oriented strategies can be offered to young women who suffer from recurrent cystitis. Recommending a change in contraception to oral contraceptive pills, intrauterine devices, or nonspermicidal, lubricated condoms may be helpful.

Cranberry juice and cranberry extract have long been proposed as a possible way to prevent UTIs. Cranberries supposedly contain a substance that changes the surface properties of Escherichia coli and prevents it from adhering to the bladder wall. A recent Cochrane Review identified 10 studies comparing the effects of cranberry products with placebo, juice, or water. There was evidence to show cranberries in the form of juice or capsules could prevent recurrent UTIs in women. A reasonable dose in capsule form is 300–400 mg twice daily. As for juice, 8 oz 3 times daily of unsweetened juice is recommended. It is unclear how long the duration should be.

Prophylactic antibiotics, either low-dose daily antibiotics or postcoital antibiotics, remain the mainstay of prevention of recurrent UTIs for young women and can reduce recurrence rates by ≤95%.

B. Postmenopausal Women

Risk factors for cystitis in older women include urologic factors such as incontinence, cystocele, and postvoid residual; hormonal factors resulting in a lack of protective lactobacillus colonization; and a prior history of cystitis. For the above mentioned risk factors, the most easily administered effective prevention is estrogen.

There are many possible ways to administer estrogen. These include traditional oral hormone replacement therapy, which is still considered indicative (after thorough discussion with the patient of risks and benefits) for menopausal symptoms, vaginal estrogen rings, or vaginal creams.

The only form of estrogen that has been proven to decrease recurrent UTIs in postmenopausal women is vaginal. The usual side effects of estrogen can be seen with vaginal use as well as oral. These include breast tenderness, vaginal bleeding, vaginal discharge, and vaginal irritation. Contraindications (as with oral estrogens) include a history of endometrial carcinoma, breast carcinoma, thromboembolic disorders, and liver disease. Patients’ functional and cultural abilities should be considered before prescribing vaginal applications.

One study compared the effects of cranberry extract (500 mg daily) to trimethoprim for the prevention of recurrent UTIs in older women. There was only a slight advantage of the antibiotic over cranberry extract.

C. Young Men

The only studies focusing on prevention of UTI in young men have investigated infant circumcision; because the risk of UTI is so low in normal men, these studies are prohibitively expensive. In boys with recurrent UTI or high-grade ureteral reflux, the NNTs are 11 and 4, respectively. The complication rate of circumcision is 2–10%, with adverse sequelae ranging from minor transient bleeding (common) to amputation of the penis (extremely rare). It does appear to decrease the chance of UTI in boys and men. The risk of UTI in normal boys hovers around 1% in the first 10 years of life, given that the number needed to treat (NNT) for circumcision is 111.

D. Future Trends in Prevention

Several investigations are ongoing in finding ways to prevent recurrent urinary tract infections, given the high prevalence and health burden that they impose. Vaginal vaccines are working their way through clinical trials and are not yet commercially available; whether they will prove to be more efficacious than prophylactic antibiotics is yet to be determined. Currently, a sublingual bacterial vaccine is also in development. This also looks promising, but needs more research.

Clinical Findings

A. Symptoms and Signs

Symptoms include dysuria, ideally felt more internally than externally, and of sudden onset; suprapubic pain; cloudy, smelly urine; frequency; and urgency.

Physical examination in the afebrile, otherwise healthy patient with a classic history is done essentially to rule out other diagnoses and to ensure that red flags are not present. The examination might range from checking a temperature and percussing the costovertebral angles to a full pelvic examination, depending on where the history leads. There are no pathognomonic signs on physical examination for cystitis.

B. Laboratory Findings

Laboratory studies include dipstick test of urine, urinalysis, and urine culture. In some cases laboratory tests are not required to diagnose cystitis with high accuracy; however, they should probably be omitted only in settings where follow-up can be easily arranged in case of failure of treatment, which would, of course, indicate further workup. Figure 23-1 provides a diagnostic algorithm for cystitis.

1. Urine dipstick testing

Dipstick findings are positive for leukocyte esterase or nitrite, or both. Several references now support treatment of simple, uncomplicated UTI in the young, nonpregnant woman on the grounds of clinical history alone, if that history leads to high suspicion for cystitis (and low suspicion of STD). For women with an equivocal clinical history, urine dipstick analysis may suffice to reassign the women to high or low suspicion and treat or not treat accordingly.

2. Urinalysis

Urinalysis will be positive for WBCs, with few or no epithelial cells. It should be noted, however, that urinalysis is more expensive than dipstick analysis and only minimally more accurate.

3. Urine culture

The gold standard of diagnosis is a culture growth of 100,000 (10⁵) organisms in a midstream clean-catch sample. However, some patients have classic clinical cases of UTI and only 100 (10²) organisms on culture. Few laboratories are equipped to detect anything fewer than 10⁴ organisms. Culture is strongly suggested if a relapsing UTI or pyelonephritis is suspected to ensure sensitivities and eradication (see Figure 23-1).

C. Imaging Studies

Imaging studies are seldom required for patients with simple uncomplicated UTIs.

D. Special Tests

These tests are generally required only for failures of treatment, symptoms suggesting a diagnosis other than cystitis, or complicated cystitis (see section on complicated cystitis, later).

Differential Diagnosis

See Table 23-2.

Complications

There are virtually no complications from repeated uncomplicated cystitis if it is recognized and treated. Delay in treatment may lead to ascending infection and pyelonephritis. In the case of infection with urea-splitting bacteria, “infection stones” of struvite with bacteria trapped in the interstices may be formed. These stones lead to persistent bacteriuria and must be completely removed to clear the infection. Proteus mirabilis, Staphylococcus saprophyticus, and Klebsiella bacteria can all split urea and lead to stones.

Treatment

A. Acute Cystitis

There is ample evidence from randomized clinical trials to support the superiority of 3-day antibiotic therapy to 1-day treatment and, equivalently, of therapy for longer periods of time, with the exception of nitrofurantoin. This is true for treatment of older, noninstitutionalized women as well. Trimethoprim-sulfamethoxazole, in the absence of allergies to sulfa and local resistance rates of >10–20%, should be considered first-line therapy. Risk factors for trimethoprim-sulfamethoxazole resistance include recent antibiotic exposure, recent hospitalization, diabetes mellitus, three or more UTIs in the past year, and possibly use of oral contraceptive pills or estrogen replacement therapy. For patients who are allergic to sulfa drugs, a 5–7-day course of nitrofurantoin or a 3-day course of a fluoroquinolone (eg, ciprofloxacin) can be used. However, because of concern regarding fluoroquinolone resistance and frequency of cystitis, they should be used sparingly. β-Lactam antibiotics are not as effective as other classes of drugs against urinary pathogens and should not be used as first-line agents except in pregnant patients.

B. Acute Cystitis in the Pregnant Woman

Treatment with amoxicillin, a cephalosporin, nitrofurantoin, or another pregnancy-safe antibiotic for 7 days remains the standard. Asymptomatic bacteriuria, if found on cultures, is treated in pregnant women with the same antibiotics (see section on asymptomatic bacteriuria, earlier).

C. Prophylaxis for Recurrent Cystitis

Low-dose, prophylactic antibiotics have been shown to decrease recurrences by ≤95%. Most recommendations suggest starting prophylaxis after a patient has had more than three documented UTIs in 1 year. Prophylactic antibiotics are usually administered for 6 months to 1 year but can be given for longer periods of time. Antibiotics can be taken daily at bedtime or used postcoitally by women whose infections are associated with intercourse (Table 23-3). Unfortunately, prophylaxis does not change the propensity of these women for recurrent UTIs; when prophylaxis is stopped, approximately 60% of women develop a UTI within 3–4 months. Prophylaxis should not start until cultures have shown no growth after treatment, to rule out bacterial persistence.

Prognosis

Long-term prognosis in terms of kidney function is excellent; prognosis of arresting recurrent cystitis without permanent prophylaxis is not as good. New preventive treatments are currently being explored, and it is hoped that these will prove beneficial.

General Considerations

The infections listed above warrant further workup by a physician or referral to an urologist. These infections should all be cultured to ensure that the antibiotics used are appropriate and that the organisms are sensitive to the chosen antibiotic.

Clinical Findings

Special tests should include x-ray or computed tomography (CT) to evaluate for stones, intravenous pyelogram (IVP) to evaluate anatomy and stones, and cystoscopy and biopsy to rule out interstitial cystitis, cancer, or unusual pathogens.

Treatment

Patients with complicated UTIs should be treated with long-course (≥10–14-day), appropriate antibiotics. Single-dose or 3-day regimens are not appropriate for this group of patients.

General Considerations

Acute urethral syndrome is a term used by some to describe a young, healthy, sexually active woman who complains of recent-onset symptoms of cystitis but does not meet strict guidelines for diagnosis of cystitis (growth of ≤10⁴ or 10⁵ organisms on culture). Some authors now feel that even 100 CFUs found on culture of a dysuric woman represent a true UTI. Because most laboratories are equipped to detect only ≥10⁴ organisms, these are patients in usual practice found to have “negative” cultures. They may have positive or negative urine dipstick analysis and positive or negative spun urine for bacteria, although bacteria and white blood cells (WBCs) in the urine are more convincing for cystitis than a completely negative workup.

Clinical Findings

Testing depends on the physician’s assessment of the patient. In patients at low risk of acquiring a sexually transmitted disease (STD), no testing might be appropriate or maybe only after failure of empirical treatment for cystitis. In patients at higher risk of acquiring an STD, Chlamydia testing, by either cervical swab, urine polymerase chain reaction (PCR), or ligase chain reaction (LCR), might be appropriate.

Differential Diagnosis

This syndrome is not well defined. It is usually taken to represent an early cystitis, but it can also be an STD (Chlamydia trachomatis has been noted in women with the previously described symptoms).

Treatment

There is some evidence that the acute urethral syndrome will respond to antibiotics commonly used in the treatment of UTIs. Because the prevalence of C. trachomatis was found to be high in at least one study of women with these symptoms, use of antibiotics effective against STDs or Chlamydia testing for patients who do not respond completely to a course of antibiotics is highly recommended.

General Considerations

Isolated urethritis in men or women is almost always an STD, most often caused by C. trachomatis. This syndrome is differentiated from acute urethral syndrome by the timecourse of symptoms; symptoms that have a gradual onset or persist without evolution into classic cystitis symptoms, including suprapubic symptoms such as pain, urgency, or frequency, are more indicative of urethritis than of acute urethral syndrome.

Clinical Findings

It can be very difficult to differentiate a symptomatic chlamydial infection from bacterial cystitis with coliform organisms, and testing for both may be required. The advent of Chlamydia urine PCR or LCR tests makes ruling out Chlamydia much easier than in the past, as the same urine sample can be sent for both tests.

Treatment

See Chapter 14 for current diagnosis and treatment of STDs such as Chlamydia.

General Considerations

Prostatitis is a very common disease among men, with a prevalence and incidence among men ranging between 11% and 16%. There are apprximately 2 million office visits per year for prostatitis (1% of all primary care office visits), so it is useful for the primary care practitioner to be able to evaluate men for symptoms of prostatitis.

Previously, prostatitis was simply described as “acute,” “chronic,” or “nonbacterial.” In 1995 the National Institutes of Health (NIH) revised the categorization of prostatitis, and the disease is now differentiated into four categories, as follows:

• Category I: acute bacterial prostatitis

• Category II: chronic bacterial prostatitis

• Category IIIA: inflammatory chronic pelvic pain syndrome

• Category IIIB: noninflammatory chronic pelvic pain syndrome

• Category IV: asymptomatic inflammatory prostatitis

Category IV is a diagnosis made incidentally, while working up other symptoms, and is not considered severe enough to require treatment. Discussion of category I, or acute bacterial prostatitis, follows. The other categories are discussed separately in this chapter.

Acute bacterial prostatitis is different from other types of prostatitis in that it is a well-defined entity with a relatively clear-cut etiology, diagnosis, and treatment. Acute bacterial prostatitis is caused by typical uropathogens and responds well to antibiotic treatment.

Prevention

There is no evidence for interventions that will prevent spontaneous prostatitis.

Clinical Findings

Symptoms and signs include dysuria, frequency, and urgency; low back, perineal, penile, or rectal pain; or tense or “boggy” tender prostate. Fever and chills may be present.

Laboratory findings include a urine dipstick analysis that is positive for leukocyte esterase or nitrites, or both, and urine culture that is positive for a single uropathogen. Imaging studies are rarely performed for acute uncomplicated prostatitis.

Prostatic massage is not generally performed in patients with acute bacterial prostatitis because it may lead to acute bacteremia.

Differential Diagnosis

Abnormal anatomy may include urethral strictures, polyps, diverticula, redundancies, or valves anywhere in the system from the penis to the kidneys (Table 23-4).

Complications

Complications of acute bacterial prostatitis may include ascending infection, infection-related stones, abscess, fistula, cysts, and acute urinary retention. In the case of acute urinary retention precipitated by prostatitis, a suprapubic catheter rather than a Foley catheter should be placed to avoid damage to the prostate.

Treatment

Treatment is determined by the severity of illness as well as local resistance rates. In cases of very ill patients, broad-spectrum parenteral antibiotics should be initiated. Typically, a penicillin or penicillin derivative and an aminoglycoside can be used. As the illness is treated, the patient can be transitioned to oral therapy with either a quinolone or trimethoprim-sulfamethoxazole for at least 3–4 weeks. Less ill patients can be started on oral therapy with a quinolone or trimethoprim-sulfamethoxazole, again for 3–4 weeks. An α-blocker can be considered for mild urinary retention. A urinary catheter should be considered for more severe retention.

Prognosis

The prognosis is very good for patients with acute uncomplicated bacterial prostatitis.

General Consideration

Chronic bacterial prostatitis, or NIH category II prostatitis, is quite rare, and consequently very few studies have examined it. Bacterial disease represents only a small percentage of the cases of chronic prostatitis. It has been estimated that the percentage of both acute and chronic bacterial prostatitis cases constitute only 5–10 of all prostatitis diagnoses, and of the bacterial cases, the vast majority are acute.

Prevention

Early and sufficient treatment of acute bacterial prostatitis is considered by some authors to prevent chronic prostatitis.

Clinical Findings

A. Symptoms and Signs

Symptoms and signs include dysuria, frequency, and urgency; prostatic tenderness on examination; low back pain; and perineal, penile, or rectal pain. Symptoms are usually present for more than 3 months.

B. Laboratory and Imaging Findings

A urine dipstick analysis will be positive for leukocyte esterase or nitrites, or both. Additionally, a 4- or 2-glass test (discussed below) will be positive for prostatic origin. A transrectal prostatic ultrasound should be performed if an abscess or a stone is suspected.

C. Special Tests

1. 4-glass test

Not used by the majority of practitioners, this is a localization test for chronic prostatitis. The patient should not have been on antibiotics for a month, should not have ejaculated for 2 days, and needs a reasonably full bladder. Signs and symptoms of urethritis or cystitis should have been worked up previously and treated. To perform the test, the patient first cleans himself and carefully retracts the foreskin, then urinates the first 5–10 mL into a sterile container (VB₁). He then urinates 100–200 mL into the toilet, and a second 10–20-mL sample into a sterile container (VB₂). Prostatic massage is then done, milking secretions from the periphery to the center, and any expressed prostatic secretions (EPSs) are caught in a third sterile container. The patient then cleans himself again, and urinates a final 10–20 mL sample into a fourth container (VB₃).

All urine samples are examined microscopically and cultured. Expressed prostatic secretions are wet-mounted, examined, and cultured. The test is positive for prostatic localization if WBCs per high-power field (HPF) and colony counts in VB₃ are ≥ 10 times greater than in VB₁ or VB₂, or if there are 10 polymorphonuclear leukocytes (PMNL)/HPF in the wet mount. If there is a significant colony count in both VB₂ and VB₃, the patient should be treated for 3 days with nitrofurantoin, which does not penetrate the prostate, and the test should be repeated.

2. 2-glass test

A verified modification of the 4-glass test, this test requires an initial clean-catch urine sample, prostatic massage, and a postmassage urine sample. It is functionally equivalent to the VB₂ and VB₃ portions of the 4-glass test and more often used in clinical practice.

Differential Diagnosis

See Table 23-4.

Complications

Complications of chronic bacterial prostatitis may include ascending infection, infection-related stones, abscess, fistula, cysts, and acute urinary retention.

Treatment

Antibiotic treatment with quinolones has shown the best results. Therapy is with an oral quinolone for at least 4–6 weeks. Trimethoprim-sulfamethoxazole for 1–3 months can also be considered. α-blockers may provide some benefit to treatment as well.

Prognosis

The prognosis for treatment of chronic bacterial prostatitis is not known. A clear differentiation of which patients will respond to antibiotics and which will not has not been obtained.

General Considerations

Chronic abacterial prostatitis was renamed by the NIH in 1995. It is now called chronic pelvic pain syndrome and can be further subclassified into inflammatory, meaning with inflammatory cells isolated in tests, or noninflammatory. This change was made in an attempt to recognize that the pain syndrome that physicians have been referring to as “chronic abacterial prostatitis” or even “prostatodynia” in the absence of inflammatory cells on examination has never been proved to originate in the prostate.

The NIH further divided chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) into two categories: inflammatory (IIIA) and noninflammatory (IIIB). In category IIIA prostatitis, leukocytes are found in semen, in expressed prostatic secretions, or in a postprostatic massage urine sample. In category IIIB prostatitis, no leukocytes are found in secretions. Recent evidence suggests cytokines may play a role in diagnosis in the future. Current research efforts include the Chronic Prostatitis Clinical Research Network, founded in 1997 by the NIH to investigate the chronic pelvic pain syndrome. Their work is ongoing and not definitive at this time.

The etiology of chronic prostatitis remains unknown. Current theories include infection with unusual or fastidious organisms, lower urinary tract obstruction or dysfunctional voiding, intraprostatic ductal reflux and subsequent chemical irritation with urea from urine forced into the gland, immunologic or autoimmune processes, or neuromuscular causes, such as reflex sympathetic dystrophy. Although none of these theories has been proved, continued research, it is hoped, will increase our understanding of this problem.

Prevention

Trials of preventive measures for chronic prostatitis or chronic pelvic pain syndrome are lacking, and risk factors for prostatitis or chronic pelvic pain have not been investigated.

Clinical Findings

A. Symptoms and Signs

Symptoms include dysuria, frequency, urgency, other irritative voiding symptoms, and pain in the perineal area for >3 of the last 6 months.

B. Laboratory Findings

Laboratory testing shows no evidence of current cystitis or demonstrable bacterial infection. Patients with inflammatory-type chronic pelvic pain syndrome have leukocytes in expressed prostatic secretions or postprostatic massage urine.

C. Special Tests

If the patient has hematuria, urine cytology should be performed. The 2-glass test (first part of a clean-catch urine sample in one bottle; prostatic massage milking from periphery to center; second urine sample into a sterile container) has been shown to be as reliable as the more complicated 4-glass test (discussed earlier) at distinguishing chronic bacterial prostatitis and inflammatory and noninflammatory prostatitis.

Differential Diagnosis

See Table 23-4.

Treatment

There is no clear-cut prescription for the treatment of chronic prostatitis of either the inflammatory or noninflammatory type. This treatment discussion therefore groups inflammatory and noninflammatory prostatitis into one entity for discussion.

Although CP/CPPS does not have a bacterial etiology, antimicrobials do improve symptoms in ≤50% of patients. Patients with a shorter duration of symptoms are more likely to respond. The antimicrobials utilized most include fluoroquinolones and trimethoprim/sulfamethoxazole for 4–6 weeks. α-blockers such as tamsulosin, terazosin, and doxazosin have shown some improvement in patients as well. Once again, the sooner treatment is started, the better the outcomes. At least 6 weeks of therapy are needed with α-blockers. A combination of antimicrobial and α-blocker shows slight improvement over monotherapy. Despite high use by providers, nonsteroidal anti-inflammatory drugs (NSAIDs) have shown only minimal effects. Unless the patient has concomitant benign prostatic hyperplasia (BPH), 5α-reductase inhibitors (eg, finasteride) have also demonstsrated only minimal effects.

There are several other modalities of treatment that need further review: (1) transurethral microwave thermotherapy (TUMT), (2) cooled transurethral microwave thermotherapy (cTUMT), (3) transurethral needle ablation (TUNA), (4) botulinum toxin A injections, (5) transurethral resection of the prostate (TURP), (6) electromagnetic therapy, and (7) electroacupuncture and application of capsaicin on the perineal area. Although none of these have been studied extensively, modalities 2 and 6 show promising results. A recent study also showed the efficacy of fluoxetine 20 mg/d for 3 months in treating symptoms of refractory chronic prostatitis/chronic pelvic pain syndrome.

Table 23-5 reviews controlled trials that have shown possible efficacy of treatments.

Prognosis

The prognosis for chronic prostatitis and chronic pelvic pain syndrome category III is not good. Prognosis appears to be worse for patients with previous episodes or more severe pain.

General Considerations

Pyelonephritis is an infection of the kidney parenchyma. It has been estimated to result in >100,000 hospitalizations per year. Information on outpatient visits is not readily available, but because many cases are now managed on an outpatient basis, it is likely to be seen by most primary care providers. Pyelonephritis usually results from upward spread of cystitis but can also result from hematogenous seeding of the kidney from another infectious source. The infection can be complicated by stones or renal scarring if untreated but usually resolves without sequelae in young, healthy people if treated promptly.

The most common bacteria involved are the same organisms that cause uncomplicated cystitis: E. coli, S. saprophyticus, Klebsiella species, and occasionally Enterobacter. As with simple cystitis, women with genetic predispositions are more commonly affected than other women.

Prevention

There are no recent studies on prevention of pyelonephritis. Prompt treatment of cystitis may prevent some cases of pyelonephritis, but this has not been demonstrated.

Clinical Findings

Symptoms and signs include fever, chills, malaise, dysuria, and flank pain. Nausea and vomiting may also occur.

Laboratory findings include a urine dipstick analysis that is positive for leukocyte esterase or nitrites and urine culture showing >100,000 CFUs.

Imaging studies are seldom required unless the patient is diabetic or there is suspicion that stones are complicating the infection, in which case a CT scan is the test of choice.

Differential Diagnosis

See Table 23-6.

Complications

Diabetic patients can experience emphysematous pyelonephritis. It is a severe necrotizing renal infection characterized by gas production within the renal parenchyma. This is diagnosed by CT scan or other imaging study showing gas in the renal collecting system or around the kidney. In a diabetic patient with emphysematous pyelonephritis, the definitive treatment is percutaneous drainage. If there is extensive, diffuse gas, nephrectomy is advised, as the mortality rate in diabetics approaches 75%. This condition rarely occurs in nondiabetic patients and is often related to obstruction. In some of these cases, relief of the obstruction and antibiotics may suffice.

Stones can complicate pyelonephritis by causing a partial or complete obstruction. These stones can be spontaneous or “infection” stones of struvite, caused by urea-splitting organisms. Stones complicating pyelonephritis must be removed before the infection can completely resolve.

People with a history of childhood pyelonephritis can experience renal scarring and recurrent infections. These scars are unusual in healthy adults with pyelonephritis. Young men with pyelonephritis should be investigated for a cause.

Patients who do not respond to 48 hours of appropriate antibiotics should be worked up for occult complicating factors or other diagnoses.

Treatment

The best drugs for treatment of pyelonephritis are bactericidal, with a broad spectrum to cover Gram-positive and Gram-negative bacteria, and concentrate well in urine and renal tissues. Aminoglycosides; aminopenicillins such as amoxicillin with clavulanic acid, ticarcillin, or piperacillin; cephalosporins; fluoroquinolones; or, in extreme cases, imipenem, are all appropriate. First-line outpatient treatment is usually a fluoroquinolone. Cure rates have been reported to approach 90% with a 10–14-day course of antibiotics. However, studies show similar cure rates with a 7-day course of ciprofloxacin.

Patients experiencing severe nausea and vomiting who are unable to tolerate oral agents may need to be hospitalized for parenteral therapy. Patients with severe illness, suspected bacteremia, or sepsis should also be admitted.

Prognosis

Prognosis after an acute episode of uncomplicated pyelonephritis in a previously healthy adult is excellent.