{
  "abstract": "Objectives Syphilis infections are high among men who have sex with men (MSM) on HIV pre-exposure prophylaxis (PrEP). Point-of-care (POC) testing may improve diagnosis and treatment. We performed a field evaluation of the Chembio dual path platform (DPP) Syphilis Screen and Confirm treponemal/non-treponemal POC test within an HIV PrEP programme in Hanoi, Vietnam.Methods From December 2023 to July 2024, males aged ≥16 years enrolled in the HIV PrEP programme who reported sex with men in the last year were enrolled. Specimens were tested using the Chembio DPP syphilis screen and confirm test and reference treponemal (Abbott Bioline or Determine) and non-treponemal (rapid plasma reagin (RPR)) tests. Positive per cent agreement (PPA), negative per cent agreement (NPA), positive predictive value (PPV), negative predictive value (NPV) and Cohen’s kappa were calculated comparing the DPP versus reference tests.Results We enrolled 400 participants; median age was 26.4 years (IQR 22.5–30.4); one invalid test was excluded. The prevalence of a reactive treponemal test was 35.3% (141/399). For the DPP treponemal test, PPA was 75.2% (95% CI 67.2% to 82.2%), NPA was 96.9% (95% CI 94% to 98.7%), PPV was 93% (95% CI 86.8% to 96.4%), NPV was 87.7% (95% CI 83.4% to 91%), and Cohen’s kappa was 0.75. For the DPP non-treponemal test, PPA was 36.5% (95% CI 23.6% to 51%), NPA was 99.4% (95% CI 97.9% to 99.9%), PPV was 90.5% (95% CI 71.1% to 97.4%), NPV was 91.3% (95% CI 88% to 93.7%), and Cohen’s kappa was 0.48 (95% CI 0.33 to 0.61). For RPR titres ≥1:8, PPA and Cohen’s kappa increased to 85.7% (95% CI 57.2% to 98.2%) and 0.67 (95% CI 0.47 to 0.81), respectively.Conclusions Among MSM in an HIV PrEP programme with high syphilis prevalence, the DPP treponemal test performed well. While non-treponemal performance was lower, it was strong for RPR titres ≥1:8, suggesting it could aid in identifying high-titre syphilis infections more likely to be transmissible.",
  "authors": [
    {
      "affiliations": [
        "David Geffen School of Medicine, University of California, Los Angeles, California, USA"
      ],
      "name": "Ursula Biba"
    },
    {
      "affiliations": [
        "Center for Training and Research on Substance Abuse-HIV, Hanoi Medical University, Hanoi, Viet Nam"
      ],
      "name": "Hao T M Bui"
    },
    {
      "affiliations": [
        "Center for Training and Research on Substance Abuse-HIV, Hanoi Medical University, Hanoi, Viet Nam"
      ],
      "name": "Linh TP Nguyen"
    },
    {
      "affiliations": [
        "Center for Training and Research on Substance Abuse-HIV, Hanoi Medical University, Hanoi, Viet Nam"
      ],
      "name": "Huong T Dang"
    },
    {
      "affiliations": [
        "Center for Training and Research on Substance Abuse-HIV, Hanoi Medical University, Hanoi, Viet Nam"
      ],
      "name": "Thanh T Bui"
    },
    {
      "affiliations": [
        "Center for Training and Research on Substance Abuse-HIV, Hanoi Medical University, Hanoi, Viet Nam"
      ],
      "name": "Thanh C Nguyen"
    },
    {
      "affiliations": [
        "Center for Training and Research on Substance Abuse-HIV, Hanoi Medical University, Hanoi, Viet Nam"
      ],
      "name": "Nguyen S Dau"
    },
    {
      "affiliations": [
        "Center for Training and Research on Substance Abuse-HIV, Hanoi Medical University, Hanoi, Viet Nam"
      ],
      "name": "Loc Q Pham"
    },
    {
      "affiliations": [
        "Center for Training and Research on Substance Abuse-HIV, Hanoi Medical University, Hanoi, Viet Nam"
      ],
      "name": "Le Minh Giang"
    },
    {
      "affiliations": [
        "Division of Infectious Diseases, David Geffen School of Medicine, University of California, Los Angeles, California, USA"
      ],
      "name": "Paul C Adamson"
    }
  ],
  "title": "Field evaluation of a dual treponemal/non-treponemal point-of-care test for syphilis within an HIV pre-exposure prophylaxis programme in Hanoi, Vietnam",
  "uid": "ff99e65e-1831-54ba-aa3c-a1321b04d95b"
}