What is the most common causative organism of epididymitis in men under 35 years old?

Chlamydia trachomatis and Neisseria gonorrhoeae are the most common causative organisms of epididymitis in men under 35 years old, primarily due to the sexually transmitted nature of these infections. In this demographic, epididymitis often arises from sexually acquired infections, making these pathogens the leading culprits.

Chlamydia trachomatis is particularly notable; it can lead to inflammation of the epididymis, often asymptomatic at first, which can result in delays in diagnosis and treatment. Neisseria gonorrhoeae, while less prevalent than chlamydia, frequently coexists with chlamydial infections, necessitating treatment for both to prevent complications.

The other organisms listed, while they can cause different types of infections, are less commonly associated with epididymitis in this age group. Haemophilus influenzae and Streptococcus pneumoniae are more associated with respiratory infections rather than sexually transmitted diseases. Escherichia coli, while it can be a causative agent of epididymitis, is more common in older patients or those with significant risk factors like urinary tract abnormalities. Thus, the sexually transmitted pathogens are predominant in the younger male population affected by epid