Non-venereal treponematoses

Abstract

Abstract Treponemal infections comprise venereal syphilis and the non-venereal (endemic) treponematoses (e.g. yaws, pinta, endemic syphilis). The treponemal diseases have similar clinical manifestations (initial lesions followed by secondary manifestations) and all exhibit the phenomenon of latency. Almost any lesion produced by the three non-venereal treponematoses may also be seen in venereal syphilis, but there is no congenital transmission and no cardiovascular/neurological complications in yaws. Small genetic differences have been found between the causative agents of the treponemal infections, but none of these variations differentiates the subspecies. The immune response in venereal syphilis and non-venereal treponematoses is identical; reactive serological tests for syphilis (non-treponemal tests e.g. RPR, VDRL and treponemal tests e.g. TPHA, FTA-Abs) cannot distinguish syphilis from a non-venereal treponematosis. The worldwide population at risk of non-venereal treponematoses is estimated at 34 million, all in developing countries (mainly infants, children and adolescents). Yaws occurs primarily in warm, humid areas of Africa, South America, the Caribbean, South East Asia and some Pacific islands. Pinta is now confined to populations in remote areas of Central and South America. Endemic syphilis is a disease of hot, dry countries; it is mostly eliminated from the Eastern Meditteranean and the Middle East, but major foci remain in Africa (Sahel region). Benzathine penicillin is the first-choice treatment. Patients and their contacts should receive 1.2 MU intramuscularly; children under 10 years should be given one-half of this dose. Resistance to penicillin has not been proven. Tetracyclines, doxycycline and erythromycin are alternatives in patients allergic to penicillin.