Advances in molecular epidemiology of Treponema pallidum and its neurotropic subtypes

Since the development of molecular typing system for Treponema pallidum based on acidic repeat protein(arp)gene and Treponema pallidum repeat(tpr)gene in 1998, there have been reports on the epidemiological characteristics of Treponema pallidum subtypes from various countries in the world. The tp0548 and rpsA genes also have been used for enhancing the molecular typing of Treponema pallidum. Predominant subtypes of Treponema pallidum have been reported in various regions, and there is a high variety in the subtypes of Treponema pallidum, with 14d and 14f as the most frequent subtypes. Further more, some specific subtypes of Treponema pallidum are associated with clinical manifestations of syphilis. Studies have found that some neurotropic subtypes of Treponema pallidum, for example, 14a, 14d/f and 19d/c types are related to neurosyphilis. Determining specific Treponema pallidum subtypes associated with neurosyphilis is of great significance for the clinical diagnosis, treatment and prediction of prognosis of syphilis. Key words: Syphilis; Treponema pallidum; Neurosyphilis; Epidemiology; Molecular typing