ABSTRACT
There are a variety of nontreponemal test (NTT) and treponemal test (TT) kits for the serologic diagnosis of syphilis. Because of the complexity of the infection (multiple clinical stages) and the different antigens used in these kits, a systematic evaluation of the accuracy of the currently available commercial tests is warranted. Our objective was to evaluate the performance of commercially available tests for the diagnosis of syphilis infection. In this study, we analyzed one NTT (Venereal Disease Research Laboratory [VDRL] test, Wiener Laboratories, Rosario, Argentina) and two TTs (fluorescent treponemal antibody absorption [FTA-ABS] test, Euroimmun, Lübeck, Germany, and syphilis recombinant ELISA v. 4.0 test [ELISA], Wiener Laboratories, Rosario, Argentina) using a panel of 187 samples, including serum samples from 31 individuals with primary syphilis, 77 with secondary syphilis, and 79 with latent syphilis. An additional 192 samples from uninfected individuals and 323 serum samples from individuals with other diseases were included. The sensitivities of the VDRL, ELISA, and FTA-ABS tests were 97.9%, 100%, and 96.3%, respectively. The VDRL and ELISA tests showed a specificity of 100%, and the FTA-ABS test showed a specificity of 99.5%. Accuracy was 98.9% for the VDRL test, 100% for the ELISA, and 97.9% for the FTA-ABS test. For primary, secondary, and latent syphilis, the ELISA achieved a diagnostic performance of 100%, whereas the sensitivity for the VDRL and FTA-ABS tests ranged from 96.8% to 98.7% and 93.7% to 98.7%, respectively. No difference was observed when the tests were used as traditional or reverse algorithms. In general, all three tests are able to discriminate positive and negative samples for syphilis, regardless of the diagnostic algorithm.
ABSTRACT
BACKGROUND: Little is known about the aetiology of urethral discharge syndrome (UDS) and genital ulcer disease (GUD) in Brazil due to limited access to laboratory tests and treatment based mainly on the syndromic approach. OBJECTIVES: To update Brazilian treatment guidelines according to the current scenario, the first nationwide aetiological study for UDS and GUD was performed. METHODS: Male participants with urethral discharge (UD) and/or genital ulcer (GU) reports were enrolled. Sample collection was performed by 12 sentinel sites located in the five Brazilian regions. Between 2018 and 2020, 1141 UD and 208 GU samples were collected in a Universal Transport Medium-RT (Copan). A multiplex quantitative PCR kit (Seegene) was used to detect UD: Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), M. hominis (MH), Neisseria gonorrhoeae (NG), Trichomonas vaginalis (TV), Ureaplasma parvum (UP), U. urealyticum (UU) and another kit to detect GU: cytomegalovirus (CMV), Haemophilus ducreyi (HD), herpes simplex virus type 1 (HSV1), herpes simplex virus type 2 (HSV2), lymphogranuloma venereum (LGV), Treponema pallidum (TP) and varicella-zoster virus (VZV). RESULTS: In UD samples, the frequency of pathogen detection was NG: 78.38%, CT: 25.6%, MG: 8.3%, UU: 10.4%, UP: 3.5%, MH: 3.5% and TV: 0.9%. Coinfection was assessed in 30.9% of samples, with 14.3% of NG/CT coinfection. The most frequent pathogen identified in GU was HSV2, present in 40.8% of the samples, followed by TP at 24.8%, LGV and CMV at 1%, and HSV1 at 0.4%. Coinfection of TP/HSV2 was detected in 4.4% of samples. VZV and HD were not detected. In 27.7% of the GU samples, no pathogen was detected. CONCLUSION: This study provided the acquisition of unprecedented data on the aetiology of UDS and GUD in Brazil, demonstrated the presence of a variety of pathogens in both sample types and reaffirmed the aetiologies known to be most prevalent globally.
