{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,26]],"date-time":"2026-09-26T05:38:34Z","timestamp":1790401114993,"version":"4.1.0"},"reference-count":32,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2025,8,20]],"date-time":"2025-08-20T00:00:00Z","timestamp":1755648000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Background and Objectives: This retrospective single-center study aimed to evaluate the epidemiological, clinical, and laboratory characteristics of syphilis cases diagnosed at our hospital between 2005 and 2024, with a focus on the performance of serological tests used for diagnosis. The study also sought to characterize changing epidemiological trends of syphilis over this 20-year period. Materials and Methods: Data from 671 patients with confirmed syphilis diagnoses were retrospectively analyzed. Demographic information, transmission routes, co-infection status, and serological test results\u2014including Rapid Plasma Reagin (RPR) and Indirect Hemagglutination Assay (IHA)\u2014were evaluated. Statistical analyses were performed using chi-square and Fisher-based tests, with Bonferroni correction applied for multiple comparisons Results: Of the 671 cases, 74.6% were male and 25.4% female, with the highest incidence in the 22\u201341 age group. The number of diagnosed cases increased approximately 6-fold after 2016 compared to the preceding years. Unprotected sexual contact was the most common transmission route. HIV co-infection was present in 32.6% of cases, predominantly in males. Significant differences in RPR and IHA titers were observed across clinical stages of syphilis, with notably higher titers in late latent and neurosyphilis cases. Conclusions: The 6-fold increase in syphilis diagnoses since 2016, alongside a high rate of HIV co-infection, underscores the need for targeted prevention and screening programs for high-risk populations. Serological testing remains essential for diagnosis and disease monitoring.<\/jats:p>","DOI":"10.3390\/medicina61081491","type":"journal-article","created":{"date-parts":[[2025,8,20]],"date-time":"2025-08-20T13:18:14Z","timestamp":1755695894000},"page":"1491","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["The Resurgence of Syphilis: A 20-Year Evaluation of Epidemiological Trends and Serological Test Performance Using Rapid Plasma Reagin and Indirect Hemagglutination Assays"],"prefix":"10.3390","volume":"61","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-1725-0644","authenticated-orcid":false,"given":"Melda","family":"Payasl\u0131o\u011flu","sequence":"first","affiliation":[{"name":"Department of Medical Microbiology, Faculty of Medicine, Bursa Uluda\u011f University, 16000 Bursa, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0864-4989","authenticated-orcid":false,"given":"\u0130mran","family":"Sa\u011fl\u0131k","sequence":"additional","affiliation":[{"name":"Department of Medical Microbiology, Faculty of Medicine, Bursa Uluda\u011f University, 16000 Bursa, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7380-2501","authenticated-orcid":false,"given":"Esra","family":"Kazak","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases and Clinical Microbiology, Faculty of Medicine, Bursa Uluda\u011f University, 16000 Bursa, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,8,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"574","DOI":"10.1111\/jdv.16946","article-title":"European guideline on the management of syphilis","volume":"35","author":"Janier","year":"2021","journal-title":"J. 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