The commonest cause of dysuria in the young, single, sexually active male is urethritis rather than cystitis.
Urethritis is usually the result of a sexually acquired infection and may be conveniently divided into gonorrhea or "gonococcal urethritis" and "not-gonorrhea" or "non-gonococcal urethritis" (NGU). NGU is also known as "non-specific urethritis" (NSU).
Other symptoms associated with urethritis include urethral discharge, which may not be noticed by the patient, and frequency (Figure 13.1).
The following are the causes of NGU:
• C. trachomatis (40-60%). Although these cases should be called "chlamydial urethritis," the term "Chlamydia-positive NGU" is often used.
• Mycoplasma genitalium
• Ureaplasma urealyticum (? 10-20%). There is still some debate concerning the role of ureaplasmas in urethritis.
The following make up only a small percentage of cases, hence most NGU is truly non-specific, that is no specific organism can be isolated.
• Trichomonas vaginalis
• Herpes simplex virus
• Adenovirus (usually acquired through oral sex)
• E. coli (usually causes cystitis although it has been documented as a cause of urethritis in homosexual men)
• adenovirus (acquired by oral sex from a partner with adenovirus pharyngeal infection
• Certain anaerobes (e.g. Bacteroides urealyticus)
• Traumatic (e.g. postcatheterization, after pencil or biro insertion)
• Reactive (e.g. postdysenteric Reiter's syndrome may be associated with a urethritis). This is not sexually acquired.
Figure 13.1. Mucoid urethral discharge due to chlamydia
To diagnose urethritis the following investigations should be performed:
(1) Urethral swab Gram stain: A small foam swab or plastic loop is inserted into the opened meatus and the distal urethra gently swabbed. Secretions are then transferred on to a microscope slide for Gram staining and microscopy.
The presence of >4 polymorphs per HPF (X1000) is diagnostic of urethritis.
(2) Two-glass urine test: The patient is asked to pass the first 20-50 ml of his urinary stream into a glass and the second part of the stream into a second glass (any remaining in the bladder can be directed into the urinal). The presence of "threads" or "specks" of pus in the first glass with a clear second glass indicates an anterior urethritis. Pus in both glasses suggests a posterior urethritis or cystitis. if this is the case, send the first glass or an MSU to the laboratory for culture. Patients with a profuse discharge due to NGU or gonorrhea may show pus in both glasses; however, this will be much heavier in the first glass.
Phosphaturia is a common cause of cloudy urine and may be mistaken for pyuria. The addition of acetic acid will rapidly clear the urine if phosphates are present; if the urine remains cloudy then pyuria is the likely cause.
A rather more scientific method of diagnosing urethritis from the first catch urine is to examine the resuspended urinary sediment under the microscope. The presence of >15 polymorphs in any of five random fields (X400) indicates a urethritis. Some studies have suggested that examination of the urine may be a more sensitive method of detecting mild urethritis than the urethral Gram stain.
Cases of mild urethritis may be missed if the patient has recently passed urine before the above investigations are performed. For this reason, patients should be asked to hold on to their urine for at least three hours prior to assessment. if the history is suggestive of urethritis and the initial investigations prove negative, repeat testing should be performed early in the morning, the patient having held on to his urine overnight.
(3) Whenever possible, a urethral swab should also be taken for detection of Chlamydia, as occasionally chlamydial infection may be present in the absence of an obvious urethritis. Finding Chlamydia, however, does not alter patient management. Tetracycline is first-line treatment for both Chlamydia-positive and Chlamydia-negative NGU.
(4) Gonococcal urethritis is far less common than NGU, but a urethral swab should be taken for N. gonorrhoeae culture. Remember that the gonococcus is particularly delicate and may well not survive an overnight delay before plating on to specific culture media. if there is likely to be a delay, place the swab in the refrigerator rather than keeping at room temperature. However, if gonorrhea is considered a possible diagnosis, the patient should ideally be referred to GU medicine so that swabs may be plated on to the appropriate culture media and incubated prior to transport to the laboratory. The important issue of contact tracing can also be addressed.
(5) Most laboratories are currently unable to routinely test for Mycoplasma genitalium infection.
(6) Send an MSU or first-catch urine for microscopy and culture if the two-glass urine test suggests posterior urethritis/cystitis of urine dipstix testing shows the presence of nitrites or blood.
13.2 MANAGEMENT OF NON-GONOCOCCAL URETHRITIS
Most GP surgeries do not have access to immediate microscopy and there may be a delay in transporting microbiology specimens to the laboratory; therefore, patients with suspected urethritis should be referred to GU medicine for assessment. Urethritis is considered an urgent problem requiring immediate attention. A telephone call to the clinic before sending along the patient is appreciated, however, as most clinics run an appointment system.
First-line treatment for NGU should be with either a tetracycline or azithromycin. Oxytetracycline 500 mg qds for 10 days is relatively cheap but compliance may be poor compared with, for example, doxycycline 100 mg bd for 7days.
Azithromycin 1 g stat or 500 mg stat followed by 250 mg daily for four days are useful alternatives, both providing good coverage for chlamydial infection with the five day course being more effective against Mycoplasma genitalium infection.
Erythromycin stearate 500 mg bd for 14 days and ofloxacin 200 mg bd for 7 days are alternative second-line treatment options.
Sexual partners must be assessed and an antibiotic prescribed, namely a tetracycline, azithromycin or erythromycin, even in the absence of infection. The possibility of missing a chlamydial infection with the subsequent development of asymptomatic pelvic infection leading to infertility or ectopic pregnancy warrants such a policy.
Patients should be reassessed following treatment to ensure cure. Resolution of symptoms does not always indicate eradication of infection, hence the importance of repeating tests after treatment. The initial lack of response to treatment may result from poor compliance, reinfection, or persistent infection. if persistence is considered likely, retreat with erythromycin or azithromycin (or tetracycline if erythromycin or azithromycin was used as first-line treatment). Reinforce the need to avoid sexual intercourse until partners have been assessed and treated and advise against frequent self-examination, masturbation, spicy foods, and excessive alcohol that may aggravate symptoms. A longer course of tetracycline together with metronidazole should be considered if the urethritis persists. Patients with continued symptoms together with objective evidence of urethritis may warrant urethroscopy, urethral ultrasound, or a urethrogram.
13.2.1 Recurrent Urethritis
A small number of men suffer repeated episodes of NGU. Some of these will be caused by reinfection from new or previously untreated partners; however, recurrence of urethritis without sexual contact or within a relationship where the sexual partner has received treatment is well recognized. if both partners are monogamous, further treatment of the female partner is
probably not warranted. Most clinicians would re-treat the symptomatic male although previous courses of tetracycline, azithromycin and erythromycin significantly reduce the likelihood of ongoing infection.
Some cases of recurrent urethritis are thought to be due to "immunological hypersensitivity" to a previous infection that results in a persisting inflammatory response.
13.3 MANAGEMENT OF GONORRHEA
Patients with gonorrhea should be referred to a GU medicine clinic for treatment, follow-up, and contact tracing (Figure 13.2). If there is a delay before the patient can be seen, consider treating with oral cefixime 400 mg or cefrtriaxone 250 mg i.m. and then refer to the GU medicine clinic for follow-up and contact tracing.
Penicillin and ciprofloxacin resistant gonorrhea is now seen in the UK, hence the move to using a cephalosporin. Most laboratories will provide details of antibiotic sensitivities for their gonococcal isolates.
Prescribing a 7-day course of tetracycline in addition to anti-gonococcal treatment to cover possible coinfection with Chlamydia is to be recommended. Patients should reattend for "tests of cure" after treatment and to follow up issues regarding partner notification.
Figure 13.2. Mucopurulent urethral discharge due to gonorrhoea
13.4 MANAGEMENT OF URINARY TRACT INFECTION
As mentioned above, dysuria in the young, sexually active male is more likely to be due to urethritis than to cystitis or urinary tract infection. If a UTI is considered the most likely diagnosis, consider treating with antibiotics which achieve therapeutic concentrations in the prostate (e.g. trimethoprim, norfloxacin, ciprofloxacin).
Men with acute pyelonephritis or who suffer more than one episode of cystitis warrant urological investigation.
13.5 IMPORTANT POINTS
(1) Consider a diagnosis of urethritis rather than cystitis in the "unmarried," sexually active man with dysuria. Urethritis should also be considered in the married or cohabiting man but proceed with a little more caution!
(2) Initial investigations should include a urethral Gram stain and two-glass urine test. If both glasses of the two-glass urine test contain pus, send off the first glass or an MSU for microscopy and culture and treat as cystitis.
(3) If microscopy is unavailable in the GP surgery, the patient should be referred to a GU medicine clinic for urgent assessment. Contact tracing can then also be addressed and the opportunity taken to provide health education and information about the condition.
(4) Remember that "contact tracing" or "partner notification" involves rather more than providing antibiotics for the sexual partner. Partners should be clinically assessed and the possibility of other sexual partners being involved must be addressed.
(5) Consider the diagnosis of urethritis in men and women with dysuria and an MSU showing sterile pyuria.
(6) NGU is sexually acquired in the majority of cases. Sexual partners must be assessed and treated.
(7) Although this chapter has focused on men presenting with dysuria, remember that both gonococcal and, in particular, NGU may be asymptomatic. Such individuals may pass on their infection unknowingly to sexual partners and act as important transmitters of disease within the community.