1493. Effect of HIV status on early syphilis treatment response in the era of combination antiretroviral therapy
Session: Poster Abstract Session: Sexually Transmitted Infections
Friday, October 5, 2018
Room: S Poster Hall
  • 1493_IDWPOSTER.pdf (301.5 kB)
  • Background:

    Rates of incident early syphilis are increasing and HIV-coinfection is common. Syphilis treatment for HIV-positive individuals does not differ from that of the general population, although data published prior to combination antiretroviral therapy (cART) suggest that HIV-infected persons may be less likely to achieve expected serologic responses to treatment (SRT).   


    We conducted a cohort study of early syphilis diagnosed in a large HIV clinic and a public sexually transmitted diseases (STD) clinic in San Diego. SRT was defined as a fourfold or greater decline in rapid plasma reagin (RPR) titer following syphilis treatment. We compared SRT at 6 and 12 months post-treatment between HIV-infected and HIV-uninfected persons.


    Of 1,239 early syphilis cases reviewed, 742 (61%) were included in the analysis. Reasons for exclusion included lack of follow-up RPR (n=454), non-reactive RPR at syphilis diagnosis (n=33), and incomplete data (n=10). Of those analyzed, 533 (72%) were HIV-positive; 168 (23%) HIV-negative; HIV status was unknown for 41 (5%). Overall, 449 (60%) and 657 (89%) of analyzed cases achieved SRT 6 and 12 months after treatment, respectively. HIV-positive cases were less likely to achieve SRT at 12 months than HIV-negative cases (464/533 [87%] vs. 160/168 [95%], p=0.003, Figure 1), as were early latent syphilis cases (285/348 [82%]) vs. primary (102/117 [92%]) and secondary syphilis (264/277 [94%]) (Table 1).


    In this cohort of early syphilis cases, most achieved SRT within 12 months of treatment, but only 60% achieved SRT within 6 months.  Significantly lower 12-month SRT responses were seen in HIV-positive compared to HIV-negative persons and in early latent compared to primary and secondary syphilis. The impact of cART use, viral suppression, and treatment choice on outcomes is being analyzed.    

    Table 1. Serologic Response to Treatment by Syphilis Clinical Stage.

    Syphilis Stage

    RPR Titer Response

    Primary  N=117      

    Secondary N=277     

    Early Latent N=348


    6 months post-treatment

                     ≥4-fold decline

    70 (60%)

    177 (64%)

    202 (58%)

                     <4-fold decline

    47 (40%)

    100 (36%)

    146 (42%)


    12 months post-treatment

                     ≥4-fold decline

    108 (92%)

    264 (95%)

    285 (82%)

                     <4-fold decline

    9 (8%)

    13 (5%)

    63 (18%)



    Helen King, MD1, Winston Tilghman, MD2, Katya Prakash, MD1, Aaron Kofman, MD1, Theodoros Katsivas, MD MAS1, Feng He, MS1, Sonia Jain, PhD1 and Charles Hicks, MD1, (1)University of California, San Diego, La Jolla, CA, (2)Infectious Hepatitis and STDs, San Diego County Department of Public Health, San Diego, CA


    H. King, None

    W. Tilghman, None

    K. Prakash, None

    A. Kofman, None

    T. Katsivas, None

    F. He, None

    S. Jain, None

    C. Hicks, None

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