Question category: Tropical medicine
A 22 year old male has recently had unprotected sex and has notices the development of a firm lesion on his penis. He states it begin as a small bump which then ulcerated and the became a firm lesion. It is not painful. He has associated inguinal lymphadenopathy which is not painful. You suspect syphilis however his EIA, FTA abs, TPHA and VDRL are negative. Which other test if positive will confirm early primary syphilis?