Treponema pallidum is the causative agent of syphilis.  In most cases, syphilis is transmitted through close sexual contact, though there are cases of transmission from mother to child called congenital syphilis.  Syphilis has different phases, occurring at different times once infected.  Primary syphilis occurs at the onset of infection resulting in a chancre at the site of infection.  Secondary syphilis occurs around 3 months after initial infection.  The secondary phase of syphilis results in lesions and rashes, often affecting the palms and soles, which can last for several months.  If left untreated, this becomes the late stage of syphilis.  The tertiary phase is the most destructive, and may not occur for years after initial infection.  In this phase syphilis causes destructive lesions on the skin and bones.  It can begin to affect the cardiovascular system and the central nervous system.  Syphilis cannot be cured, once infected with T. pallidum it will always be present in the blood, but it can be treated for its symptoms and greater protection against transmitting the disease to others.