{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,5]],"date-time":"2025-11-05T21:18:27Z","timestamp":1762377507653,"version":"3.37.3"},"reference-count":20,"publisher":"BMJ","issue":"3","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["Sex Transm Infect"],"accepted":{"date-parts":[[2023,12,2]]},"published-print":{"date-parts":[[2024,5]]},"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p>The chemiluminescence immunoassay (CLIA) is a widely used screening test for syphilis. A CLIA seroconversion in the absence of a positive line immunoassay (LIA) or rapid plasma reagin (RPR) could indicate either an early incubating syphilis or a false positive result. We aimed to evaluate the diagnostic value of such seroconversions.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>We retrospectively analysed data of clients visiting the Centre for Sexual Health Amsterdam between July 2013 and August 2021 with a positive CLIA and a negative RPR and negative or indeterminate LIA (at time T<jats:sub>o<\/jats:sub>), and a preceding visit (T<jats:sub>\u22121<\/jats:sub>) with a negative CLIA &lt;6 months of T<jats:sub>o<\/jats:sub>(\u2018unconfirmed CLIA seroconversion\u2019). If available, data of follow-up visits (T<jats:sub>1<\/jats:sub>) &lt;2 months of T<jats:sub>o<\/jats:sub>were also included. A syphilis diagnosis was confirmed if darkfield microscopy or PCR for<jats:italic>Treponema pallidum<\/jats:italic>was positive at T<jats:sub>0<\/jats:sub>or T<jats:sub>1<\/jats:sub>, or if RPR and\/or LIA were positive at T<jats:sub>1<\/jats:sub>.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>We included data of 107 clients with unconfirmed CLIA seroconversion. The value of CLIA seroconversion could not be established in 13 (12.1%) clients. In the remaining 94 clients, the unconfirmed CLIA seroconversion was confirmed as early syphilis in 72 (76.6%) clients and probable syphilis in 6 (6.4%) clients. In 16 (17.0%) clients, the unconfirmed CLIA seroconversion was regarded as a false positive reaction of whom 4 (5.3%) clients had a seroreversion of the CLIA at T<jats:sub>1<\/jats:sub>.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>The majority of unconfirmed CLIA seroconversions represented early syphilis infections. Therefore, additional<jats:italic>T. pallidum<\/jats:italic>PCR, a follow-up consultation or early treatment is recommended.<\/jats:p><\/jats:sec>","DOI":"10.1136\/sextrans-2023-055973","type":"journal-article","created":{"date-parts":[[2024,1,22]],"date-time":"2024-01-22T18:25:48Z","timestamp":1705947948000},"page":"138-142","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":1,"title":["Seroconversion in syphilis screening without positive confirmatory tests points at early infection"],"prefix":"10.1136","volume":"100","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1466-5292","authenticated-orcid":false,"given":"Silvia Achia","family":"Nieuwenburg","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9538-1501","authenticated-orcid":false,"given":"Vita Willemijn","family":"Jongen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4903-7002","authenticated-orcid":false,"given":"Maarten","family":"Schim van der Loeff","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Henry","family":"de Vries","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alje","family":"van Dam","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2024,1,22]]},"reference":[{"key":"2025020223001368000_100.3.138.1","doi-asserted-by":"publisher","DOI":"10.1038\/nrmicro.2016.141"},{"key":"2025020223001368000_100.3.138.2","unstructured":"Sexually transmitted infections (Stis). Available: https:\/\/www.who.int\/news-room\/fact-sheets\/detail\/sexually-transmitted-infections-(stis) [Accessed 9 Aug 2022]."},{"key":"2025020223001368000_100.3.138.3","unstructured":"Sexually transmitted infections in the Netherlands in 2021. RIVM. n.d. Available: https:\/\/rivm.openrepository.com\/bitstream\/handle\/10029\/625860\/2022-0023.pdf?sequence=3&isAllowed=y"},{"key":"2025020223001368000_100.3.138.4","doi-asserted-by":"crossref","first-page":"389","DOI":"10.1093\/cid\/cix326","article-title":"Increased Syphilis testing of men who have sex with men: greater detection of asymptomatic early Syphilis and relative reduction in secondary Syphilis","volume":"65","author":"Chow","year":"2017","journal-title":"Clin Infect Dis"},{"key":"2025020223001368000_100.3.138.5","doi-asserted-by":"publisher","DOI":"10.1086\/655832"},{"key":"2025020223001368000_100.3.138.6","doi-asserted-by":"publisher","DOI":"10.1016\/j.clinmicnews.2014.12.001"},{"key":"2025020223001368000_100.3.138.7","doi-asserted-by":"publisher","DOI":"10.1128\/CVI.00681-14"},{"key":"2025020223001368000_100.3.138.8","doi-asserted-by":"publisher","DOI":"10.1093\/cid\/ciaa307"},{"key":"2025020223001368000_100.3.138.9","doi-asserted-by":"publisher","DOI":"10.3343\/alm.2016.36.1.23"},{"key":"2025020223001368000_100.3.138.10","doi-asserted-by":"publisher","DOI":"10.1016\/j.jaad.2019.02.073"},{"key":"2025020223001368000_100.3.138.11","doi-asserted-by":"publisher","DOI":"10.1177\/0956462415621660"},{"key":"2025020223001368000_100.3.138.12","doi-asserted-by":"crossref","first-page":"365","DOI":"10.1097\/OLQ.0000000000000446","article-title":"The significance of isolated reactive Treponemal enzyme immunoassay in the diagnosis of early Syphilis","volume":"43","author":"Caswell","year":"2016","journal-title":"Sex Transm Dis"},{"key":"2025020223001368000_100.3.138.13","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-0691.2006.01566.x"},{"key":"2025020223001368000_100.3.138.14","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.00720-09"},{"key":"2025020223001368000_100.3.138.15","unstructured":"Available: https:\/\/english.ccmo.nl\/investigators\/additional-requirements-for-certain-types-of-research\/non-wmo-research\/file-research"},{"key":"2025020223001368000_100.3.138.16","doi-asserted-by":"publisher","DOI":"10.1258\/095646202320753718"},{"key":"2025020223001368000_100.3.138.17","doi-asserted-by":"publisher","DOI":"10.1093\/infdis\/jis459"},{"key":"2025020223001368000_100.3.138.18","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.02259-06"},{"key":"2025020223001368000_100.3.138.19","doi-asserted-by":"publisher","DOI":"10.1093\/infdis\/jir524"},{"key":"2025020223001368000_100.3.138.20","doi-asserted-by":"publisher","DOI":"10.1136\/sextrans-2017-053284"}],"container-title":["Sexually Transmitted Infections"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/sextrans-2023-055973","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,2,3]],"date-time":"2025-02-03T07:02:05Z","timestamp":1738566125000},"score":1,"resource":{"primary":{"URL":"https:\/\/sti.bmj.com\/lookup\/doi\/10.1136\/sextrans-2023-055973"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,1,22]]},"references-count":20,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2024,4,18]]},"published-print":{"date-parts":[[2024,5]]}},"alternative-id":["10.1136\/sextrans-2023-055973"],"URL":"https:\/\/doi.org\/10.1136\/sextrans-2023-055973","relation":{},"ISSN":["1368-4973","1472-3263"],"issn-type":[{"type":"print","value":"1368-4973"},{"type":"electronic","value":"1472-3263"}],"subject":[],"published":{"date-parts":[[2024,1,22]]}}}