Background: New reverse sequence syphilis testing algorithms have detected significant numbers of serodiscordant patients with a confirmed positive treponemal tests and negative non- treponemal tests. The risks of sequelae in these patients in the antibiotic era are unknown. Our goal was to determine the probability of neurosyphilis, auditory or ocular syphilis among persons with serodiscordant serum syphilis serologies.
Methods: A retrospective chart review was conducted on all subjects in the Johns Hopkins Patient Database who had a positive serum treponemal test and who underwent a cerebrospinal fluid (CSF) examination between 1994 and 2012. More detailed information such as demographics, clinical presentation, HIV status, CD4 count, HIV RNA and CSF abnormalities were abstracted in the subset of patients who were found to be serodiscordant. We defined ‘confirmed neurosyphilis’ as a positive CSF VDRL with or without pleocytosis. We defined ‘suspected neurosyphilis’ as CSF pleocytosis (≥ 5 cells/ml) with or without CSF protein elevation. Ocular/auditory syphilis were defined as compatible ocular/auditory findings in a person with serological evidence of syphilis independent of CSF abnormalities.
Results: Of the 470 patients who had positive serum treponemal tests and underwent a CSF examination, 48(10.2%) adults were serodiscordant. Only 5 (10.4%) of those were diagnosed and treated for ocular (N=3) auditory (N=1), or neurosyphilis (N=1). All patients had negative CSF VDRL. Those with ocular syphilis presented with bilateral uveitis, anterior uveitis, and bilateral optic neuritis. The patient with auditory syphilis presented with hearing loss. All had normal CSF parameters. The patient with suspected neurosyphilis was an HIV- infected alcoholic male who presented with subacute altered mental status and pleocytosis on CSF examination.
Conclusions: Neurological complications of syphilis occur rarely in persons with serodiscordant serum syphilis serologies. Ocular complaints were most frequent and diagnoses were presumptive.