Detection of Treponema pallidum DNA in Oropharyngeal Swabs and Whole Blood for Syphilis Diagnosis.

BACKGROUND: Syphilis diagnosis relies on serological tests, which may be falsely nonreactive or may be reactive but not reflect current syphilis. METHODS: Polymerase chain reaction for detection of T. pallidum DNA was performed on 123 oropharyngeal swabs, 120 whole bloods, and 46 lesion exudate swabs from 123 untreated individuals with syphilis (cases); oropharyngeal swabs from 148 at-risk controls without syphilis; and 73 oropharyngeal swabs and 36 whole bloods from 73 individuals recently treated for syphilis. RESULTS: Most (90.2%) cases had early syphilis. T. pallidum DNA was detected in 33 (26.8%) of 123 oropharyngeal swabs, 32 (26.7%) of 120 bloods, and 30 (65.2%) of 46 lesion exudate swabs. T. pallidum DNA was detected in 49 (40.8%) of 120 individuals in whom both oropharyngeal swabs and blood were tested. T. pallidum was more likely to be amplified from oropharyngeal swabs when it was amplified from blood than when it was not (15 of 32 [46.9%] vs. 17 of 88 [19.3%], P = 0.003). For each 2-fold increase in serum rapid plasma reagin titer, the odds of detection of T. pallidum DNA in oropharyngeal swabs increased by 1.44 (95% confidence interval, 1.14-1.82, P = 0.003). T. pallidum DNA was not detected in oropharyngeal samples from controls, but it was detected in 3 (8.3%) of 36 bloods from individuals recently treated for syphilis: 2 at 1 day and 1 at 5 days after initiation of syphilis treatment. CONCLUSIONS: Nucleic amplification tests can identify recent T. pallidum infection and may be particularly useful for diagnosis of very early or asymptomatic syphilis.

Cognitive impairment in syphilis: Does treatment based on cerebrospinal fluid analysis improve outcome?

BACKGROUND: Individuals with previous syphilis may experience cognitive impairment. The goal of this study was to determine if those at high risk for laboratory-defined neurosyphilis are cognitively impaired, and whether treatment based on cerebrospinal fluid (CSF) findings results in better outcomes. METHODS: Participants had a new syphilis diagnosis, serum RPR titer ≥ 1:32 or peripheral blood CD4+ T cells ≤ 350/ul (in persons living with HIV) and did not endorse neurological symptoms. They underwent computerized cognitive assessment with the CogState. Thirty-two were randomized to either undergo lumbar puncture (LP) or to not undergo LP and 14 underwent LP; 64 were not randomized and 48 opted to undergo LP. RESULTS: Demographics, cognitive complaints and cognitive impairment did not differ between randomized and nonrandomized participants. Two-thirds were cognitively impaired, and impairment was not more common in those with cognitive complaints. The adjusted odds of increased severity of impairment were 3.8 times greater in those with CSF pleocytosis compared to those without. Time to cognitive normalization, improvement or decline did not differ between those who did not undergo LP and those who underwent LP and whose treatment was based on CSF analysis. Taking into account pre-treatment cognitive impairment, the risk of cognitive decline was lower in those with CSF pleocytosis treated for neurosyphilis compared to those without CSF pleocytosis not treated for neurosyphilis, (HR 0.24 (95% CI 0.07-0.88], p = 0.03). CONCLUSION: In individuals at high risk for laboratory-defined neurosyphilis, cognitive complaints are not a good indicator of cognitive impairment. Severity of cognitive impairment was greater in those with CSF pleocytosis. Identification and treatment of those with neurosyphilis may mitigate subsequent cognitive decline.