We reviewed 68 cases of possible neurosyphilis among 573 syphilis cases in King County, WA, from 3rd January 2012 to 30th September 2013; 7.9%(95% confidence interval, 5.8%–10.5%) had vision or hearing changes, and 3.5%(95% confidence interval, 2.2%–5.4%) had both symptoms and objective confirmation of complicated syphilis with either abnormal cerebrospinal fluid or an abnormal ophthalmologic examination.

Symptomatic neurosyphilis is considered to be a rare complication of syphilis, but modern estimates of its prevalence have been based largely on retrospective studies of health department syphilis records. 1, 2 Standard syphilis case-report forms and investigations might incompletely capture cases of neurosyphilis. To our knowledge, no contemporary studies have sought to prospectively identify symptoms of neurologic, otologic, or ocular complications in patients with syphilis. The objective of this study was to determine the prevalence of symptoms of complicated syphilis and the prevalence of confirmed symptomatic complicated syphilis in a population-based sample. Disease intervention specialists (DIS) conducting syphilis partner services in Seattle & King County have asked all persons with syphilis about symptoms of complicated infection as part of routine case investigations since February 2012. Disease intervention specialist interviews of patients with early and unknown duration syphilis include a questionnaire that captures symptoms of vision changes, hearing changes, and tinnitus using a standardized protocol and interview form. For all persons with these symptoms, DIS recommend follow-up with a medical provider for additional evaluation. In addition to the interview record, the Washington state sexually transmitted disease case-report form includes a field for medical providers reporting a syphilis case to indicate a diagnosis of neurosyphilis. Although DIS do not routinely interview patients with late latent syphilis, neurosyphilis in those cases can be captured through the case report, provider interview to confirm treatment, or review of the treatment regimen used.