Performance Assessment of Treponemal and Nontreponemal Tests for the Diagnosis of Acquired Syphilis.

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.

Evaluating the diagnostic accuracy of TpN17 and TmpA recombinant proteins in syphilis detection: a phase II study.

Syphilis is a sexually transmitted infection (STI) caused by the spiral bacterium Treponema pallidum. Diagnosis is based on epidemiology, clinical and serology, but serodiagnosis is challenging because distinct clinical forms of the infection may influence serological performance. Several recombinant Treponema pallidum-proteins have already been tested for syphilis diagnosis and they are critical to achieve high accuracy in serological testing. A total of 647 samples were included in the study: 180 T. pallidum-positive samples, 191 T. pallidum-negative samples and 276 sera from individuals infected with unrelated diseases. The diagnostic potential was validated by analysis of ROC curves. For the indirect ELISA, TpN17 (100%) and TmpA (99%) showed excellent AUC values. Sensitivity values were 97.2% for TpN17 and 90.6% for TmpA, while specificity was 100% for both molecules. According to the clinical phase, TmpA ranged from 84% to 97%, with the highest value for secondary syphilis. TpN17 was 100% sensitive for the primary and secondary stages and 93.2% for recent latent syphilis. All clinical phases achieved 100% specificity. Accuracy values showed that TmpA (> 95%) and TpN17 (> 98%) presented high diagnostic accuracy for all clinical stages of syphilis. Cross-reactivity was only observed in one sample positive for Chagas disease (1.5%), when TpN17 was evaluated. On the other hand, TmpA showed reactivity for two samples positive for Chagas disease (3.1%), one sample positive for HBV (1.25%), two samples positive for HIV (9.5%) and one sample positive for HTLV (1.6%). The TmpA antigen's performance was evaluated in multiple studies for syphilis diagnosis, corroborating our findings. However, TpN17 sensitivity values have ranged in other studies. According to clinical stages of the infection, our findings obtained close performance values.

Aetiological molecular identification of sexually transmitted infections that cause urethral discharge syndrome and genital ulcer disease in Brazilian men: a nationwide study.

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.

Acute Chagas disease outbreak associated with oral transmission.

Seven individuals living in a town in the Southwest of Bahia developed sudden signs of cardiac and systemic impairment, with lethality of 28.6%. Serological tests were positive at least in one test in the five patients examined. Forty percent of the Triatoma sordida mynphs found inside or around Trypanosoma cruzi were found by blood culturig in there out five cases the homes of these cases were positive for Trypanosoma cruzi. Transmission probably occurred through consumption of water contaminated with triatomine feces. These findings emphasize the necessity to evaluation the importance of vectors like Triatoma sordida in maintaining the endemicity of this disease.

Acute Chagas disease outbreak associated with oral transmission / Surto de doença de Chagas aguda associada à transmissão oral

Seven individuals living in a town in the Southwest of Bahia developed sudden signs of cardiac and systemic impairment, with lethality of 28.6 percent. Serological tests were positive at least in one test in the five patients examined. Forty percent of the Triatoma sordida mynphs found inside or around Trypanosoma cruzi were found by blood culturig in there out five cases the homes of these cases were positive for Trypanosoma cruzi. Transmission probably occurred through consumption of water contaminated with triatomine feces. These findings emphasize the necessity to evaluation the importance of vectors like Triatoma sordida in maintaining the endemicity of this disease.

Sete indivíduos que viviam em uma cidade do sudoeste da Bahia desenvolveram sinais súbitos de envolvimento cardíaco e sistêmico com letalidade de 28,6 por cento Trypanosoma cruzi foi isolado por hemocultura em três de cinco casos examinados. Testes sorológicos foram positivos em mais de um teste nos cinco pacientes, que os realizaram. Qinquenta por cento dos Triatoma sordida encontrados na residência ou no peridomicilio dos casos estavam positivos para Trypanosoma cruzi. A transmissão provavelmente foi devido à ingestão de água contaminada por fezes de triatomíneos. Estes achados enfatizam a necessidade de se avaliar a importância de vetores como Triatoma sordida na manutenção da endemicidade da doença.