Molecular Epidemiology of Syphilis—San Francisco, 2004-2007

In Brief We describe the molecular epidemiology of syphilis in San Francisco (SF) using Treponema pallidum specimens obtained from patients examined at the SF municipal sexually transmitted diseases clinic during 2004-2007. Of 69 specimens, 52 (75%) were subtype 14d9. Single subtype predominance might reflect a closely linked sexual network in SF. A study of the molecular epidemiology of syphilis in San Francisco found that 75% of Treponema pallidum specimens were subtype 14d9, suggesting the existence of a closely linked sexual network.