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. 2021 May 1;48(5):353-356.
doi: 10.1097/OLQ.0000000000001308.

A Dual-Platform Point-of-Care Test for Neurosyphilis Diagnosis

Hemil Gonzalez, Igor Jerome Koralnik  1 , Gregory D Huhn, Lauren C Tantalo  2 , Ethan M Ritz  3 , Zachary Orban  1 , Christina M Marra  2
Affiliations

A Dual-Platform Point-of-Care Test for Neurosyphilis Diagnosis

Hemil Gonzalez et al. Sex Transm Dis. .

Abstract

Background: The diagnosis of neurosyphilis relies on cerebrospinal fluid (CSF) abnormalities (pleocytosis, elevated protein) and CSF-Venereal Disease Research Laboratory (VDRL) test. In resource-limited settings, the CSF-VDRL test may not be widely available.

Methods: We optimized a commercial immunochromatographic strip test, the DPP Chembio syphilis assay, for performance with CSF and tested centrifuged CSF samples of 71 patients with syphilis (35 with neurosyphilis and 36 without neurosyphilis). A CSF dilution of 1:4 was chosen based on agreement with CSF pools with documented results from the CSF-VDRL test and fluorescent treponemal antibody absorption test on CSF. Using an electronic reader, we obtained unit values of treponemal and nontreponemal antibodies for all study samples and generated a receiver operating characteristic curve; using the Youden index, we established diagnostic cutoffs with optimal sensitivity and specificity.

Results: Diagnostic sensitivity of the nontreponemal test was 80% (95% confidence interval, 63%-92%) and specificity was 97% (95% confidence interval, 85%-100%) for neurosyphilis diagnosis using a reactive CSF-VDRL that improved after neurosyphilis therapy as a criterion standard.

Conclusions: In this small study, the DPP Chembio test showed promising results for neurosyphilis diagnosis. Further studies are needed to assess its performance in resource-limited settings.

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Conflict of interest statement

Conflict of Interest and Sources of Funding: H.G. has received a grant from an AIDS Clinical Trials Group Minority HIV Mentoring Program award. I.J.K. has served on an advisory board for Medimmune and received royalties from UpToDate for chapters on HIV and progressive multifocal leukoencephalopathy. G.D.H. has received institutional research grants from Gilead, Janssen, Proteus, Viiv, and BMS and has served on an advisory board for Gilead, Viiv, Janssen, and Theratechnologies. C.M.M. has received royalties from Wolters Kluwer and grants from the National Institutes of Health. L.C.T. and Z.O. have no conflicts of interest to disclose.

Figures

Figure 1.
Figure 1.. Receiver operator characteristic curves.
A. Receiver operator characteristic curve of treponemal test results of Chembio test (area under the curve is 0.894). B. Receiver operator characteristic curve of non-treponemal test results of Chembio test (area under the curve is 0.910). The diagnosis of neurosyphilis was based on a reactive CSF-VDRL that normalized after neurosyphilis therapy
Figure 1.
Figure 1.. Receiver operator characteristic curves.
A. Receiver operator characteristic curve of treponemal test results of Chembio test (area under the curve is 0.894). B. Receiver operator characteristic curve of non-treponemal test results of Chembio test (area under the curve is 0.910). The diagnosis of neurosyphilis was based on a reactive CSF-VDRL that normalized after neurosyphilis therapy
See this image and copyright information in PMC

References

    1. Rowley J, Vander Hoorn S, Korenromp E, et al. Chlamydia, gonorrhoea, trichomoniasis and syphilis: global prevalence and incidence estimates, 2016. Bulletin of the World Health Organization 2019;97:548–62P. - PMC - PubMed
    1. Bank W GNI per capita, Atlas method (current US$). 20 April;Available at: https://data.worldbank.org/indicator/NY.GNP.PCAP.CD.
    1. Collaborators GH. Estimates of global, regional, and national incidence, prevalence, and mortality of HIV, 1980–2015: the Global Burden of Disease Study 2015. The lancet HIV 2016;3:e361–e87. - PMC - PubMed
    1. Joseph Davey DL, Shull HI, Billings JD, et al. Prevalence of Curable Sexually Transmitted Infections in Pregnant Women in Low- and Middle-Income Countries From 2010 to 2015: A Systematic Review. Sex Transmitted Dis 2016;43:450–8. - PMC - PubMed
    1. Kojima N, Klausner JD. An Update on the Global Epidemiology of Syphilis. Curr Epidemiol Rep 2018;5:24–38. - PMC - PubMed

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