Etiological Agents of Epididymitis

Classification by Age Group

The Centers for Disease Control and Prevention recommends that in men under 35 years, the predominant pathogens are Chlamydia trachomatis and Neisseria gonorrhoeae, transmitted sexually, while in men over 35 years, enteric gram-negative organisms (mainly Escherichia coli) are the most common causes 1, 2
The American Academy of Pediatrics and the Centers for Disease Control and Prevention suggest that Neisseria gonorrhoeae is the second most common pathogen in sexually active men 3, 4, 5
The Centers for Disease Control and Prevention notes that Escherichia coli can cause sexually transmitted epididymitis in homosexual men who practice insertive anal intercourse 3, 4, 5

The Infectious Diseases Society of America recommends that viral causes of orchitis, such as mumps virus, are the most common viral cause of orchitis 2, 6
The Centers for Disease Control and Prevention suggests that Mycobacterium tuberculosis should be considered in cases that do not respond to standard antimicrobial treatment, especially in immunocompromised patients 2, 5, 6

The American Urological Association notes that in men with recent urological instrumentation, enteric gram-negative organisms are the predominant pathogens 3, 4, 5
The Centers for Disease Control and Prevention recommends that fungal and mycobacterial causes of epididymitis are more common in immunocompromised patients, such as those with HIV 2, 5

The American Academy of Family Physicians warns that a common pitfall is not considering that sexually transmitted epididymitis often presents without evident urethral symptoms, which can lead to misdiagnosis 3, 4, 5
The Infectious Diseases Society of America suggests that persistent inflammation and sensitivity after completing antimicrobial therapy should be evaluated for testicular cancer or tuberculous or fungal epididymitis 3, 5