| disease | Chronic Bacterial Prostatitis |
Chronic bacterial prostatitis is a non-acute infection of the prostate caused by one or several pathogenic bacteria. Similar to acute bacterial prostatitis, the causative agents are Gram-negative aerobic bacteria, such as Escherichia coli and Pseudomonas aeruginosa. Some clinicians believe that Gram-positive bacteria (e.g., staphylococci, streptococci, and Corynebacterium) can also cause prostatitis. However, unlike infections caused by Gram-negative bacteria, those caused by Gram-positive bacteria rarely persist or lead to recurrent infections, except for prostatitis caused by enterococci. Nevertheless, many authors remain skeptical about Gram-positive bacteria causing chronic prostatitis. Current evidence suggests that Chlamydia and Mycoplasma can also cause prostate infections, though such cases are relatively rare.
bubble_chart Pathological Changes
The routes of infection for acute and chronic bacterial prostatitis may be the same. Sometimes chronic prostatitis clearly evolves from unresolved acute prostatitis, but there are also cases without a history of acute prostatitis.
Histological examination of chronic prostatitis is nonspecific, showing milder and more localized inflammatory reactions compared to acute prostatitis. Plasma cells, macrophages, and lymphocyte infiltration can be observed within or around the acini or in the stroma. In 1979, Kohnen and Drach observed that 98% of prostates from 162 male patients who underwent prostatectomy due to prostate enlargement exhibited similar histological features. In this group of patients, there was little clinical or bacteriological evidence of prostate infection, so histological methods cannot definitively diagnose chronic bacterial prostatitis.
bubble_chart Clinical Manifestations(1) Symptoms: The symptoms of chronic prostatitis are complex. Some patients are asymptomatic, and the diagnosis is made based on the incidental discovery of asymptomatic bacteriuria. Most patients experience varying degrees of bladder irritation symptoms (such as urinary frequency, urgency, nocturia, and dysuria) and discomfort or pain in the lumbosacral or perineal regions. Rarely, fear of cold and fever may occur, which, if present, suggest an acute exacerbation of chronic prostatitis. Occasionally, myalgia and arthralgia may appear.
(2) Signs: On digital rectal examination, the prostate may appear normal, uneven, or have localized indurations. A grating sensation may be felt if larger prostatic calculi are present. Occasionally, initial or terminal hematuria, bloody semen, or urethral discharge may occur. Sometimes, epididymitis may complicate the condition.
bubble_chart Auxiliary Examination
Laboratory findings: In the absence of secondary epididymitis or acute exacerbation of chronic infection, the blood picture is generally normal, with no elevation in white blood cells. A large number of inflammatory cells are often found in the prostatic tuina fluid. Many researchers and clinicians consider more than 10 white blood cells per high-power field in prostatic fluid as abnormal, and more than 15 as leukocytosis. The presence of numerous lipid-laden macrophages in prostatic fluid is significantly correlated with prostatic inflammation. When secondary bladder infection occurs, midstream urine may show pyuria and bacteriuria, with the pathogenic bacteria consistent with those infecting the prostate.
When the urine itself is infected, collecting segmented urine and prostatic tuina fluid for bacterial culture can determine the source of the pathogenic bacteria. When using this technique, the physician must carefully collect each segment of the patient's urine and uncontaminated prostatic secretion samples. These samples are then inoculated into culture media and incubated for 24 to 48 hours, using standard microbiological methods to identify bacterial growth. When the bladder sample (midstream urine) shows no or minimal bacterial growth, the colony counts of other samples are compared to determine the site of infection. If the urethral sample (initial urine) colony count significantly exceeds (at least 10 times) that of the prostatic sample, the infection is located in the urethra; otherwise, the infection originates from the prostate.
X-ray examination: Unless there are various complications (such as prostatic calculi, prostatic hypertrophy, urethral stricture, kidney infection, etc.), excretory urography is normal.Instrumental examination: Cystoscopy or urethroscopy may reveal no abnormalities, or may show congestion and edema in the prostatic urethra, with or without inflammatory polyps. These findings are not specific to chronic bacterial prostatitis and may also be present in other prostatic inflammatory conditions.
bubble_chart Treatment Measures
(1) Special Treatment:
① Medical Treatment: Pharmacokinetic studies and clinical experience have shown that only a few antibiotics can achieve effective therapeutic concentrations in prostatic secretions under non-acute prostatitis conditions. TMP can penetrate into prostatic fluid and has been proven to successfully cure chronic bacterial prostatitis caused by sensitive bacteria. Long-term treatment (12 weeks) is more effective than short-term therapy (2 weeks).
In the absence of azotemia, the following antibiotic treatments can be selected based on bacterial culture and drug sensitivity tests:
SMZCo (TMP 160mg + SMZ 800mg), orally, twice daily, for 12 weeks.
TMP, 2 tablets (100mg/tablet) each time, twice daily, for 12 weeks.
Carbenicillin, 2 tablets (383mg/tablet) each time, four times daily, orally, for at least 4 weeks.
Minocycline 100mg orally, twice daily, for at least 4 weeks.
Erythromycin 500mg, four times daily orally, for at least 4 weeks.
Special treatment must consider the principle of individual differences, as well as the patient's tolerance to the medication. Norfloxacin and ciprofloxacin are also effective drugs for treating prostatitis.
Most patients with chronic bacterial prostatitis are rarely cured by medical treatment. However, as long as an appropriate daily oral medication is used to maintain a low-dose suppressive therapy to ensure sterile urine (e.g., TMP 100mg once daily, or TMP 160mg + SMZ 800mg once daily), the patient can remain relatively comfortable. If suppressive therapy is interrupted, the bladder urine will become re-infected, and symptoms will reappear.② Surgical Treatment: Regardless of whether chronic prostatitis can be cured by medical treatment, surgical treatment can be performed. Since prostatitis combined with stones is difficult to cure with antibiotics alone, chronic prostatic infections and prostatic stones are often indications for surgery. Unfortunately, surgical complications (sexual dysfunction and urinary incontinence) limit the choice of this procedure. If transurethral resection of the prostate can completely remove the infected tissue and stones, prostatitis can be radically cured, but this outcome is difficult to achieve because the surrounding prostatic tissues also contain numerous infected lesions.
(2) General Treatment: Hot sitz baths can alleviate symptoms, and anti-inflammatory drugs (indomethacin, ibuprofen) and anticholinergic drugs (propantheline, etc.) can relieve urinary irritation symptoms and pain.
Chronic bacterial prostatitis is difficult to cure completely, but antibiotic treatment can generally alleviate its symptoms and control the factors that cause recurrent urinary tract infections.
Since the predisposing factors have not yet been identified, prevention of this disease is difficult. Normal prostatic fluid contains zinc, which is a potent antibacterial factor. In patients with chronic bacterial prostatitis, the zinc content in the prostatic fluid is significantly reduced. Some authors suggest that this antibacterial factor in male prostatic fluid serves as a natural defense mechanism against ascending genitourinary infections. However, oral zinc supplementation in male patients does not stimulate an increase in the zinc content of the prostatic fluid. It is essential to actively treat acute bacterial prostatitis and prevent the occurrence of chronic bacterial prostatitis. Strict aseptic techniques should be employed during transurethral instrumentation and catheterization to prevent iatrogenic prostatic infection.
Recurrent urinary tract infections are characteristic of chronic bacterial prostatitis. Although during appropriate antibacterial treatment, the symptoms and signs of urinary tract infections can quickly disappear after the bacteria in the urine are killed, the same pathogen-induced infection is prone to recur after a period of time post-treatment. This occurs because while the bacteria in the urine are completely eradicated, the pathogenic bacteria within the prostate remain unchanged, as most antibiotics have difficulty penetrating the prostatic fluid. Consequently, after treatment is completed, bacteria persist in the prostate, which will eventually lead to recurrent urinary tract infections.
Ascending upper urinary tract infections and bacterial epididymitis may also be complications of chronic bacterial prostatitis. It can also lead to the formation of infected prostatic calculi, resulting in drug-refractory chronic infections. Sometimes, chronic bacterial prostatitis may be complicated by bladder neck contracture-induced bladder urethral obstruction, but whether there is a causal relationship between them remains unclear.
Male patients with acute or chronic urethritis symptoms may indicate prostatitis. Culturing or staining smears of segmented specimens from the urethra, bladder, or prostate secretions can generally determine the location of inflammation and infection.
Bladder inflammation can sometimes be confused with chronic bacterial prostatitis. Prostate infections are also prone to complicating bladder inflammation. The microbiological examination and culture of segmented urine and prostate secretion specimens mentioned above can differentiate the site of infection. If bladder inflammation is complicated by bacterial prostatitis, appropriate antibiotic treatment (using antibiotics that poorly diffuse into the prostate, such as nitrofurantoin or penicillin G) to eliminate bacteria in the bladder, followed by repeated bacterial cultures, can confirm the presence of prostate infection.
Anal conditions (such as anal fissures or thrombosed hemorrhoids) can cause perineal pain or even frequent urination, but physical examination should distinguish them.
