Epididymitis

Any infection of the reproductive organs has the capability to interfere with fertility, though it looks like this infection doesn't usually lead to lasting fertility problems when it is treated but there is a chance of obstruction or antisperm antibodies.

"Unilateral or bilateral obstruction of the genital tract (either congenital or acquired), epididymitis and varicocele are also sometimes associated with an autoimmune response against spermatozoa."
from: Antisperm Antibodies

Here are some links about epididymitis, and fertility for your reference:

What is Epididymitis and how is it treated?

Epididymitis And Orchitis

Orchitis and epididymitis

bacterial epididymitis

If your partner has this infection currently or he did previously I would suggest that after treatment by a doctor (probably with antibiotics), if you are TTC he should have another S/A to make sure everything is working properly.