Management of Urinary Tract Infection in Men

John D. Goodson

Roughly one in five urinary tract infections (UTIs) occur in men, and the lifetime cumulative incidence is about 15%. UTI is rare in young men, but the incidence begins to increase with age, particularly after the age of 50 years. By age 65 years, incidence in men equals that in women. In elderly debilitated patients confined to nursing homes, the prevalence may reach as high as 20% to 50%. The primary care clinician needs to know the clinical significance of UTI in men, what type of workup is indicated, who requires treatment, and what modes of therapy are most efficient and effective. UTIs account for much community antibiotic exposure, necessitating careful consideration of drug selection and duration of therapy to minimize adverse ecologic consequences spurring antibiotic resistance.

PATHOPHYSIOLOGY, CLINICAL PRESENTATION, AND COURSE (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 and 15)

Young Men

UTI in young men usually represents urethritis or the introduction of bacteria through instrumentation (e.g., bladder catheterization for surgery). At times, a congenital anomaly of the urinary tract is responsible, although usually the presentation is at an earlier age. Dysuria, frequency, and urgency accompany most forms, with urethral discharge characteristic of urethritis. Most cases of urethritis are sexually transmitted in origin and respond well to treatment (see Chapter 136). The condition of patients with an anatomic defect does not improve unless the structural problem is alleviated. Patients who respond fully to a 7-day course of antibiotics are unlikely to have any serious underlying pathology.

In some young men, uncomplicated cystitis may develop because of exposure to uropathogenic strains of Escherichia coli. The exposure is seen among men who have sex with men engaging in anal intercourse and in heterosexual men having vaginal intercourse with a colonized partner. Lack of circumcision is a risk factor, as is HIV infection with a CD4 lymphocyte of less than 200/mm³.

Middle-Aged Men

The increase in the rate of UTI that occurs in men of age 50 to 65 years parallels the increase in prostate size that occurs with hyperplasia of the gland. The enlargement leads to bladder outflow tract obstruction, and a postvoid residual begins to develop in the bladder. The reduced antibacterial activity of prostatic secretions among men in this age group may also contribute to infection risk. Infection of the prostate may serve as a nidus for recurrent UTI.

Elderly Men

With further prostatic enlargement, the postvoid residual and consequently the risk for infection continue to rise. The use of condom or urethral catheters, urinary incontinence, and history of a previous UTI are other risk factors for UTI in this age group. Asymptomatic bacteriuria may occur, especially among nursing home residents. Additional contributing factors include neurogenic bladder dysfunction (see Chapter 134) and concomitant illness (pneumonia is a common precipitant of UTI).

Despite the high prevalence of infection with pathogenic organisms, the vast majority of infected elderly men remain asymptomatic and seem to be at low risk for serious complications. However, the usual manifestations of serious, symptomatic UTI may be absent and replaced by such vague findings as “failure to thrive” or worsening mental status. Gram-negative sepsis from a urinary tract source can be life threatening. Debate continues as to whether bacteriuria per se increases mortality; studies controlling for comorbid conditions show no increase.

Bacteriology

In patients with infection caused by a single organism, E. coli accounts for about 25% of cases, other gram-negative rods (Proteus, Pseudomonas, Providencia) for another 50%, and enterococci and coagulase-negative staphylococci for the remaining 25%. Patients with indwelling catheters and those with recurrent infections and multiple antibiotic exposures are likely to have unusual organisms with resistance to multiple antibiotics. Multiple organisms are found in as many as one third of infected nursing home patients.

Biofilms

Indwelling catheters and ureteral stents can become sources of recurrent and resistant infection if they become coated with a biofilm. Such urinary tract biofilms have been found to consist of large concentrations of bacteria, particularly urease-producing Proteus species. Biofilm formation makes for resistance to both antibiotics and host defenses.

WORKUP (1, 2 and 3,16,17)

History and Physical Examination

In men, complaints of dysuria, frequency, and urgency have a predictive value of about 75% for UTI. The acute onset of hesitancy, nocturia, slow stream, and dribbling have a predictive value for UTI of about 33%. No symptoms differentiate upper from lower tract infection, with the possible exception of fever (which is rare in men with lower tract disease). Cloudy or foulsmelling urine is not diagnostic of UTI. Clinical deterioration or fever without localizing urinary symptoms in a person with an indwelling catheter should raise concern for UTI.

The temperature should be taken and a careful genitourinary tract examination performed. The urethral meatus is examined for erythema and discharge, the testes and epididymis for tenderness and swelling, and the prostate for enlargement, tenderness, fluctuance, and nodularity. In the patient with suspected acute prostatitis, palpation should be very gentle to avoid causing a bacteremia. The abdomen is checked for suprapubic distention and tenderness in the costovertebral angles.

Laboratory Studies

Urine Culture and Urinalysis

Unlike women, men require a urine culture because of the wider range of causative agents and their less predictable drug sensitivities. Current consensus criteria for diagnosis of UTI in men specify a pure culture of 10⁵ colony-forming units (CFU) per milliliter of urine. A culture that grows fewer than 10³ CFU/mL or the presence of three or more organisms (without one being predominant) is suggestive of contamination. A midstream urine sample or even an initial void sample without prior cleansing of the glans suffices for most clinical situations, even if the patient is uncircumcised. Initial and midstream urine samples correlate very well with bladder specimens (r = 0.96).

Both spun and unspun urine specimens should be examined. The spun sediment is examined for the presence of white blood cell casts (indicative of pyelonephritis) and pus, and a Gram stain is performed to identify a predominant organism, if present. A Gram stain of the unspun urine is also performed. The finding of a single organism or white blood cell per high-power field on a Gram stain of the unspun urine has a sensitivity of 85% for UTI and a specificity of 60%, which are about the same as those of other rapid diagnostic methods. Dipstick testing of the urine for pyuria can help to quickly rule out infection, with a negative test for leukocyte esterase having a high negative predictive value (see Chapter 133).

Culturing the Incontinent Patient

Culturing is necessary only if the patient is symptomatic, because only symptomatic patients benefit from treatment (see later discussion). Specimens from patients with an indwelling catheter can be obtained for culture by first cleansing the side port of the catheter with a povidone-iodine solution and then drawing up urine through a needle attached to a sterile syringe. A culture of urine drawn from an indwelling catheter is positive for organisms when 100 or more CFU/mL are present. Most patients with indwelling catheters have positive cultures.

A specimen from an incontinent patient can be obtained for culture without resorting to catheterization by cleansing the glans penis with povidone-iodine solution, applying a fresh condom catheter and drainage system, and collecting the first voided specimen in the drainage bag within 2 hours. The criterion for a positive study is the presence of more than 10⁵ CFU/mL; lesser growth is considered to represent contamination.

Straight catheterization and direct bladder aspiration are alternative methods of obtaining urine for culture in incontinent patients. The former carries a slight risk of inducing a bacteremia (see Chapter 16); skill is required to perform the latter procedure.

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