A 28-year-old man with HIV and a CD4 count of 524 cells/mm³ presents with a 4-day history of swelling and tenderness of his left testicle and scrotum. The pain has steadily increased over the past 72 hours and has been associated with mild dysuria. He has taken antiretroviral therapy consistently for 3 years and has persistently undetectable HIV RNA levels. He reports no recent trauma and no prior genitourinary operations. In the past 6 months, he had vaginal insertive intercourse with three women; he does not have insertive anal intercourse. He denies fever, chills, hematuria, or other systemic symptoms. He is diagnosed with acute epididymitis.