What type of viruses cause viral epididymitis?

Viral epididymitis is uncommon. Mumps can causes it, perhaps others -- and there have been a few case reports of epididymitis complicating COVID-19. Sometimes doctors diagnose viral epididymitis when no bacterial cause can be found (like gonorrhea, chlamydia, or urinary tract infection bacteria) -- but some cases are due to non-infectious inflammation. Drug reactions sometimes do it.