A 24-year-old man experiences a brief period of dysuria accompanied by some frequency and urgency. These symptoms subside after a couple of days so he does not seek medical treatment. A few days later, however, he suddenly develops fever, chills, and a somewhat more irritating dysuria. This time the dysuria is not accompanied by noticeable urgency and frequency but, because the fever persists, he goes to see his physician. Except for the fever, his vital signs are normal. Upon physical examination, he is found to have extreme tenderness in his prostate by digital rectal examination. The prostate feels quite tense. He does not have any noticeable costovertebral angle tenderness, nor are there any other notable physical abnormalities. He says that he has not had any previous incidents that produced symptoms like the ones he has been experiencing over the past few days.

Question 2.l: What is your preliminary diagnosis?

The dysuria hints at a UTI, as do the earlier symptoms of frequency and urgency. He does not have frequency or urgency at this time, so acute cystitis is unlikely (although it may have been present earlier in this incident). The lack of costovertebral tenderness argues against pyelonephritis, although he could have an asymptomatic case. The prostate tenderness, in combination with the other symptoms, suggests prostatitis. The systemic symptoms and the lack of any previous related incidents suggest an acute prostatitis, rather than a chronic prostatitis.

Question 2.2: How can you confirm this diagnosis?

The best approach is to a urinalysis and urine culture. Prostatic massage usually produces purulent secretions with large numbers of bacteria. However, manipulation of the severely inflamed gland (and it is severely inflamed in acute prostatitis) can lead to septicemia. As a consequence, vigorous prostatic massage should be avoided in these cases. The problem can usually be identified by detection and culturing of the causative agent in the urine.

Lab Results

Figure 2.1 - Gram stain of unspun urine (Gram-negative rods & WBCs)

A urinalysis shows: sp gr 1.018, pH 6.5, protein negative, glucose negative, ketones negative, nitrite positive, leukocyte esterase positive. A Gram stain of a urine specimen reveals numerous Gram-negative bacilli and white blood cells. The urine bacterial count indicates more than 105 bacterial cells/ml. A Gram-negative bacillus is isolated from the urine culture and identified by the lab as oxidase negative with red colonies on MacConkey agar, indole negative, and urease positive (a Klebsiella species, K pneumoniae). Dysuria and pyuria, along with the characteristic symptoms noted in this case, are typical diagnostic indicators of acute prostatitis.

Question 2.3: How do you suppose this infection came about?

The vast majority of UTIs, regardless of their location, come about as ascending infections of the lower urinary tract. Fecal organisms enter the urethra, get transported to the bladder (where they may or may not produce symptomatic cystitis) and sometimes ascend into the kidneys (producing asymptomatic or symptomatic pyelonephritis) or prostate (producing prostatitis). Hematogenous infections of the urinary tract are less frequent by comparison (and there is no reason to suspect that route of infection in this case of a previously healthy young person).

Question 2.4: What are the most common causative agents of this disease?

Most cases of acute prostatitis that are not associated with the use of a urinary catheter or other complications are caused by fecal bacteria such as Escherichia coli and Klebsiella species (the causative agent in this case). Other possibilities (seen less often) include additional members of the Enterobacteriaceae (enteric bacteria) and Gram-positive cocci (mostly enterococci and the Group D streptococci). Catheter-associated cases of acute prostatitis are usually caused by typical hospital-acquired Gram negative bacilli, especially Pseudomonas aeruginosa and Klebsiella spp., but E. coli, Acinetobacter spp., and enterococci are also decent possibilities. It should be noted that many of the hospital-acquired strains are antibiotic-resistant.

Question 2.5: What is the prevalence of this disease and what groups are most susceptible?

When it occurs spontaneously, acute prostatitis most often affects young men. However, it can also be associated with the use of an indwelling urinary catheter (i.e., a nosocomial infection) at any age. Since the advent of antibiotics, the frequency of acute bacterial prostatitis has dropped markedly in the U.S.

Question 2.6: How should this case be treated?

Initially, an intravenous fluoroquinolone, third-generation cephalosporin, or aminoglycoside is administered when Gram negative rods are detected in the urine. Because enterococci are frequent, you would have to use vancomycin IV or ampicillin and gentamicin initially if the case were caused by a Gram-positive coccus. Oral treatment of enterococcal or staphylococcal infections is very difficult and must be tailored to the individual sensitivities of the infecting strain.

For the most part, these drugs do not diffuse readily into the noninflamed prostate gland. Yet, the response to antibiotics in acute bacterial prostatitis is usually prompt, possibly because the drugs penetrate more readily into the acutely inflamed gland tissue.