Syphilis infection is almost always by direct contact with infectious lesions. Since the infectious lesions of syphilis are most frequently found about the genitalia or mouth, transmission usually occurs during close physical or sexual contact. An exception to this is congenital syphilis where infection is transmitted from the mother to her fetus. Sexual contact tracing not only serves to prevent reinfection of the individual, but is a source of identification of other infectious or potentially infectious individuals and therefore is an effective way of eliminating small epidemics in the community. For every individual diagnosed as having infectious syphilis, at least one other individual with syphilis exists.
Parenteral penicillin remains the treatment of choice for all stages of syphilis.
Injections of benzathine penicillin G is preferred because adequate treatment can be given with a limited number of injections and can be easily monitored to assure completion of treatment.