title: Unexpectedly high prevalence of Treponema pallidum infection in the oral cavity of human immunodeficiency virus-infected patients with early syphilis who had engaged in unprotected sex practices.
abstract: Between 2010 and 2014, we obtained swab specimens to detect Treponema pallidum, with PCR assays, from the oral cavities of 240 patients with 267 episodes of syphilis who reported engaging in unprotected sex practices. The detected treponemal DNA was subjected to genotyping. All of the syphilis cases occurred in men who have sex with men (MSM), and 242 (90.6%) occurred in human immunodeficiency virus-infected patients. The stages of syphilis included 38 cases (14.2%) of primary syphilis of the genital region, 76 (28.5%) of secondary syphilis, 21 (7.9%) of primary and secondary syphilis, 125 (46.8%) of early latent syphilis, and seven (2.6%) others. Concurrent oral ulcers were identified in 22 cases (8.2%). Treponemal DNA was identified from the swabs of 113 patients (42.2%), including 15 (68.2%) with oral ulcers. The most common genotype of T. pallidum was 14f/f. The presence of oral ulcers was associated with identification of T. pallidum in the swab specimens (15/22 (68.2%) vs. 98/245 (40.0%)) (p = 0.01). In multivariate analysis, secondary syphilis (adjusted OR 6.79; 95% CI 1.97-23.28) and rapid plasma reagin (RPR) titres of ≥1: 32 (adjusted OR 2.23; 95% CI 1.02-4.89) were independently associated with the presence of treponemal DNA in patients without oral ulcers. We conclude that detection of treponemal DNA in the oral cavity with PCR assays is not uncommon in MSM, most of whom reported having unprotected oral sex. Although the presence of oral ulcers is significantly associated with detection of treponemal DNA, treponemal DNA is more likely to be identified in patients without oral ulcers who present with secondary syphilis and RPR titres of ≥1: 32.
authors.affiliation: Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan; Department of Healthcare Administration, Oriental Institute of Technology, New Taipei City, Taiwan.
authors.forename: C-J
authors.initials: CJ
authors.lastname: Yang
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Laboratory Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: S-Y
authors.initials: SY
authors.lastname: Chang
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: B-R
authors.initials: BR
authors.lastname: Wu
authors.affiliation: Centre of Infection Control, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: S-P
authors.initials: SP
authors.lastname: Yang
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: W-C
authors.initials: WC
authors.lastname: Liu
authors.affiliation: Centre of Infection Control, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: P-Y
authors.initials: PY
authors.lastname: Wu
authors.affiliation: Centre of Infection Control, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: J-Y
authors.initials: JY
authors.lastname: Zhang
authors.affiliation: Centre of Infection Control, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Y-Z
authors.initials: YZ
authors.lastname: Luo
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan; Department of Medical Research, China Medical University Hospital, Taichung, Taiwan; China Medical University, Taichung, Taiwan. Electronic address: hcc0401@ntu.edu.tw.
authors.forename: C-C
authors.initials: CC
authors.lastname: Hung
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: S-C
authors.initials: SC
authors.lastname: Chang
mesh_terms: D000328:Adult; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D005838:Genotype; D060005:Genotyping Techniques; D015658:HIV Infections / Q000150:complications*; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D009055:Mouth / Q000473:pathology*; D015995:Prevalence; D011446:Prospective Studies; D013587:Syphilis / Q000453:epidemiology* / Q000473:pathology*; D014210:Treponema pallidum / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D047568:Unsafe Sex; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial
keywords: Chancre; PCR; Treponema pallidum; men who have sex with men; rapid plasma reagin; sexually transmitted infection