Urethritis overview
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Seyedmahdi Pahlavani, M.D. [2]
Overview
Historical Perspective
The first known case of urethritis was described by Albert Neisser, a German doctor, in 1879. In 1904, Ludwig Waelsch described mild non-gonococcal urethritis (NGU). In the 1930s and later, Philip Thygeson and others in the United States confirmed the vertical transmission of nongonococcal urethritis (NGU).
Classification
Urethritis can be classified into two main groups:
- Infectious urethritis- This can be further subdivided into gonococcal and non-gonococcal urethritis.
- Non-infectious urethritis
Pathophysiology
The pathogenesis of urethritis varies depending on the underlying pathogen.
- Neisseria gonorrhoeae is usually transmitted to the human host via the genital tract.
- Following attachment to host cell, which is mediated by pili, gonococci become engulfed in a process known as parasite-directed endocytosis. The organism can survive inside the vacuoles and replicate.
- Chlamydia trachomatis is the most common of the non-gonorrheal pathogens that cause urethritis.
- The infectious process begins with cell surface attachment and phagocytosis by the host cell. This pathogen survives inside the cell by debilitating the cellular lysosomes, and replicating as elementary bodies (the infective form of the pathogen).
Causes
Urethritis may be caused by either infectious or non-infectious causes. Infectious causes can be further subdivided into gonorrheal and non-gonorrheal. Non-gonorrheal pathogens are the most frequent cause of urethritis; Chlamydia trachomatis is the most common among them.
Differentiating Urethritis from Other Diseases
Urethritis must be differentiated from other causes of dysuria and urethral discharge, which include acute cystitis, epididymitis, prostatitis, cervicitis, and vulvovaginitis.
Epidemiology and Demographics
Chlamydia and gonorrhea are the most commonly reported diseases to the US Centers for Disease Control and Prevention (CDC). Worldwide, there are approximately 78 million cases of gonorrhea and 131 million cases of chlamydia annually.
Incidence
- Chlamydia trachomatis is the most commonly reported disease in the United States. 1,441,789 chlamydia infections were reported to the CDC in 2014, which corresponds to a rate of 456.1 cases per 100,000 individuals.
- Gonorrhea: In 2014, a total of 350,062 cases of gonorrhea were reported in the United States, and the national gonorrhea rate increased to 110.7 cases per 100,000 individuals in the United States.
Gender
- Chlamydia trachomatis: In 2014, the overall rate of chlamydia infection in the United States among women (627.2 cases per 100,000 females) was over two times the rate among men (278.4 cases per 100,000 males).
- Gonorrhea: In 2014, the incidence of gonorrhea in the United States was reported as 120 cases per 100,000 males and 100 cases per 100,000 females.
Age
- Chlamydia trachomatis: Almost two-thirds of chlamydia infections occur among youths aged 15-24 years.
- Gonorrhea: The highest prevalence rates were observed in individuals between the ages of 20 and 24 years. This was consistent in both men and women.
Race
- Chlamydia trachomatis: In 2014, the chlamydia rate in the African-American population in the United States was 6 times the rate in Caucasians, and the rate among American Indians/Alaska Natives was almost 4 times the rate among Caucasians.
- Gonorrhea: In 2014, the rate of reported gonorrhea cases remained highest among African-Americans (405.4 cases per 100,000 individuals). The rate among African-Americans was 10.6 times higher than the rate among Caucasians (reported cases of gonorrhea among Caucasians was 38.3 cases per 100,000 individuals). The gonorrhea rate among American Indians/Alaska Natives was 159.4 cases per 100,000 population, 4.2 times that of Caucasians.
Risk Factors
The most important risk factor in developing urethritis is unprotected sex, especially among men who have sex with men. Other risk factors include:
- Low socioeconomic status
- Prior or current STD
- New or multiple sex partners
- Circumcision
Screening
According to the U.S. Preventive Service Task Force (USPSTF), all sexually active women aged under 25 years and over 25 years with increased risk should undergo screening. Factors that increase risk include:
- Prior history of sexually transmitted infection
- A new sex partner
- More than one sex partner
- A sex partner who has a sexually transmitted infection
Natural History, Complications, and Prognosis
If left untreated, urethritis will resolve within 3 months in 95% of patients. The symptoms of non-gonococcal urethritis generally abate within 3 months in 30% to 70% of untreated people.[1] Prolonged asymptomatic urethral carriage of gonococci occurs in 2% to 3% of newly infected men if left untreated.
Common complications of urethritis include:
- Acute epididymitis
- Prostatitis
- It occurs In 20% to 30% of men with non-gonorrheal urethritis (NGU); however, it is usually asymptomatic and responds to standard therapy.
- Urethral stricture
- Gonorrhea may cause urethral stricture.
- Oculogenital syndrome
- Conjunctivitis and non-gonorrheal urethritis (NGU) may be seen in approximately 4% of patients with urethritis.
Diagnosis
Diagnostic Study of Choice
History and Symptoms
A detailed history must be taken, with particular emphasis on sexual activity. Specific areas of focus when obtaining a history from the patient include:
- Recent sexual activities
- Number of sex partners or any new partner
- Use of condoms
- History of prior STDs
- History of recent urethral instrumentation (e.g., urethral catheters)
Symptoms
- Symptoms suggestive of urethritis include dysuria and urethral discharge.
Physical Examination
- The most common physical finding in urethritis is urethral discharge. The entire genital area must be examined in order to rule out other possibilities.
- Patients should be examined for inguinal lymphadenopathy, ulcers, and urethral discharge.
Laboratory Findings
Urethritis may be considered on the basis of any of the following:
- Mucoid, mucopurulent, or purulent discharge on examination
- Gram stain of urethral secretions demonstrating ≥2 WBC per field
- Positive leukocyte esterase test on first-void urine or microscopic examination of sediment from a spun first-void urine demonstrating ≥10 WBC per high power field.
Electrocardiogram
X-ray
Echocardiography and Ultrasound
CT scan
MRI
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
The preferred antibiotic regimen depends on the etiologic pathogen.
- Gonorrheal urethritis: Ceftriaxone 250 mg IM in a single dose PLUS Azithromycin 1 g PO in a single dose
- Non-gonorrheal urethritis: Azithromycin 1 g PO in a single dose OR Doxycycline 100 mg PO bid for 7 days
Interventions
Surgery
Primary Prevention
Effective measures for the primary prevention of urethritis include:
- Educating adolescents about safe sex practices
- Practicing abstinence
- Using condoms
- Limiting the number of sex partners
Secondary Prevention
In order to prevent transmission to partners and decrease the risk of antibiotic resistance, all patients must be instructed on guidelines for safe sex practice, and have screening tests done following treatment.
References
- ↑ Bennett, John (2015). Mandell, Douglas, and Bennett's principles and practice of infectious diseases. Philadelphia, PA: Elsevier/Saunders. ISBN 9781455748013.