Herpes is certainly possible and can lead the burning. Obtaining appropriate smears and cultures should be repeated to ensure that herpes isn't present. A blood test looking for the herpes antibody can be considered as well.
I would also look at the prostate. This can be done via a rectal exam as well as prostatic massage. Any prostatic fluid should be sent for analysis and culture. If negative, a transrectal ultrasound can image the prostate for any abscesses.
If infection has been ruled out, a cystoscopy can be considered to exclude anatomical abnormalities, or a CT done to rule out kidney stones.
These options can be discussed with your personal physician.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
kevinmd_