Chapter 6 : Syphilis: the Great Pox

Abstract:

In 1913, when Hideyo Noguchi isolated the same microbe from the brains of patients with insanity and paresis due to late-stage syphilis, it became clear that all of the stages of the disease were linked to one “seed of contagion,” Treponema pallidum. Although the closely related treponemes that cause yaws (T. pallidum subsp. pertenue), treponarid (T. pallidum subsp. endemicum), and pinta (T. carateum) are >95% genetically alike, a single gene (called tpp15) marks T. pallidum as distinct. Syphilis is a disease of cities, and with the high population density, changes in social habits, wearing of clothing, less frequent sharing of eating utensils, and unique opportunities for rapid transmission, the propagation of the milder forms of treponemes was reduced, allowing transmission of only the more virulent venereal forms. Treponemes are present in all the tissues but especially the blood, and there is a high level of syphilis antigen. Serologic tests (such as the Wasserman, VDRL, and RPR [rapid plasma reagin] tests) are positive. Syphilis can be transmitted from the mother to the developing fetus via the placental blood supply, resulting in congenital syphilis; this is most likely to occur when the mother is in an active stage of infection. Its control will require comprehensive programs for diagnosis as well as treatment, but it is critical that these be suited to the social and cultural dynamics of this sexually transmitted disease.