Infectious Disease Compendium

Urethritis

Diagnosis

Pain and burning with urination.

Per CDC: Mucopurulent or purulent discharge. Gram stain of urethral secretions demonstrating >5 WBCs per oil immersion field. Gonococcal infection is established by documenting the presence of WBC's containing intracellular Gram-negative diplococci. Positive leukocyte esterase test on first-void urine or microscopic examination of first-void urine demonstrating >10 WBC's per high power field.

Epidemiologic Risks

Often a sexually transmitted disease.

Microbiology

C. trachomatis, N. gonorrhea, HSV, ureaplasmas, T. vaginalis, Mycoplasm genitalium. One case of early syphilis may present as urethritis. The VDRL was negative, diagnosis made with PCR (PubMed).

In one study C. trachomatis, M. genitalium, M. hominis, U. parvum biovar 1, and U. urealytiucm biovar 2 were detected in 21.8%, 4.1%, 2.1%, and 8.5%, respectively.

Neisseria meningitides sequence type 11 is a cause urethritis in MSM with orogenital transmission (PubMed)(PubMed).

In patients with chlamydia-negative GU, coinfection with M. genitalium was associated with a 14.54-fold greater risk of PGU and coinfection with U. urealyticum biovar 2 was associated with a 3.64-fold greater risk of PGU (PubMed).

Empiric Therapy

per the CDC.

Recommended Regimens

C. trachomatis urethritis: preferred: azithromycin 1 g orally in a single dose OR doxycycline 100 mg orally twice a day for 7 days.

Alternative Regimens erythromycin base 500 mg orally four times a day for 7 days OR erythromycin ethylsuccinate 800 mg orally four times a day for 7 days OR levofloxacin 500 mg orally once daily for 7 days OR ofloxacin 300 mg orally twice a day for 7 days.

Chlamydia clearance rate is 94.8% with doxycycline arm and 77.4% for the azithromycin arm, while M. genitalium clearance rate is 30.8% with doxycycline and 66.7% for the azithromycin arm (PubMed).

Recommended Treatment for Recurrent / Persistent Urethritis

Metronidazole 2 g orally in a single dose OR Tinidazole 2 g orally in a single dose PLUS azithromycin 1 g orally in a single dose (if not used for initial episode)

Mycoplasma genitalium may be better treated with azithromycin.

Persistence after therapy for NGU depends on what you used for treatment (PubMed):

"...persistent Chlamydia in 12% and MG in 44% of participants at 4 weeks after therapy, which was associated with signs and symptoms of NGU. Persistent Chlamydia was detected in 23% of participants after azithromycin treatment vs 5% after doxycycline treatment (P = .011); persistent Mycoplasm was detected in 68% of participants after doxycycline vs 33% after azithromycin (P = .001). All but 1 Trichomonas infection cleared after tinidazole."

Expect a 25% failure rate no matter what you give (PubMed).

Mycoplasm genitalium is a common cause and resistance to available antibiotics is increasing (PubMed).

Last Update: 04/02/19.