Objectives: To evaluate the usefulness of routine lumbar puncture in non-HIV patients with untreated latent syphilis.
Methods: We conducted a prospective study in Seoul National University Bundang Hospital from May 2003 to December 2005. Participants in routine health check-ups of the Healthcare System were screened for serologic evidence of syphilis by the TPPA test. Lumbar puncture was performed, with consent, on untreated latent syphilitic patients. Neurosyphilis was defined as positivity for CSF VDRL, or pleocytosis with a positivity for CSF TPHA, or elevation of CSF protein with IgG index exceeding 0.85.
Results: Of 21,507 participants, 282 (1.4%) had serologic evidence of syphilis. 117 (41%) of these had a history of syphilis treatment, and two were seropositive for HIV. Among the 163 non-HIV patients with untreated latent syphilis, 70 (43%) underwent lumbar puncture. All the patients had VDRL titers less than 1:16. Abnormal neurologic signs or symptoms were present in eight (11%) patients. CSF abnormalities were seen in 57 (81%), but no patient (0%, 95% confidence interval: 0~6.2) was diagnosed with neurosyphilis.
Conclusions: The estimated prevalence of neurosyphilis among non-HIV patients with untreated latent syphilis and serum VDRL < 1:16, was below 6.2%.