Melbourne Sexual Health Centre, Alfred Health, Melbourne, VIC, Australia; Central Clinical School, Faculty of Nursing, Medicine and Health Sciences, Monash University, Melbourne, VIC, Australia.
Victorian Infectious Diseases Reference Laboratory, The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.
Lancet Infect Dis. 2021 Sep;21(9):1324-1331. doi: 10.1016/S1473-3099(20)30838-0. Epub 2021 Apr 22.
Syphilis transmission is increasing, and precisely how Treponema pallidum is transmitted sexually from person to person is unclear. We aimed to determine the frequency of T pallidum shedding from potentially asymptomatic sites and the stage of infection at which shedding is most frequent in men who have sex with men (MSM), who have been disproportionately affected by syphilis.
We did a prospective, cross-sectional study in MSM recruited from Melbourne Sexual Health Centre (Melbourne, VIC, Australia). Men were eligible if they were aged 18 years or older, reported sex with men during the past 12 months, and had laboratory confirmed primary, secondary, or early latent syphilis, consistent with Australian definitions. Primary and secondary syphilis lesions were swabbed and non-lesion samples were collected via oral rinse, oral cavity swab, anal canal swab, urine, and semen. Samples were tested for T pallidum using PCR assays targeting polA (lesion and non-lesion samples) and 47 kDa (non-lesion samples only) gene targets. The primary outcome was the proportion of men with T pallidum detected from potentially asymptomatic sites-namely, the mouth, anus, urethra, and semen.
Between Nov 30, 2015, and May 23, 2019, 246 MSM were screened for inclusion, of whom 200 had serologically confirmed early syphilis and were included in the study: 54 (27%) of 200 had primary syphilis, 93 (47%) had secondary syphilis, and 53 (27%) had early latent syphilis. T pallidum DNA was detected in 48 (24%; 95% CI 18·3-30·5) of 200 men by oral rinse or oral lesion swab, or both, of whom 24 had no oral lesions. Oral T pallidum detection was most frequent in those with secondary syphilis compared with those at other stages of disease (41 [44%] of 93 vs seven [7%] of 107; p<0·0001), and in men with rapid plasma reagin titres of 1/64 or higher compared with those with lower titres (37 [32%] of 117 vs 11 [13%] of 83; p=0·0026). T pallidum was detected by anal canal swab or anal lesion swab, or both, in 45 (23·0%; 95% CI 17·3-29·5) of 196 men with available samples, of whom ten had no anal lesion. Furthermore, T pallidum was detected in urine samples of 12 (6·1%, 3·2-10·3) of 198 men and in semen samples from six (12·0%, 4·5-24·3) of 50 men who provided samples. Among the 93 men with secondary syphilis, 69 (74%) had T pallidum detected at any site, and 24 (26%) had detection at two or more separate sites. Among the 54 men with primary syphilis, 49 (91%) had T pallidum detected at any site, and 11 (20%) had detection at two or more separate sites. Among the 53 men with early latent syphilis, four (8%) had T pallidum detected at any site and none had T pallidum detected at two or more separate sites.
Unrecognised oral and anal shedding of T pallidum occurs in MSM with early syphilis, most frequently in those with secondary syphilis, suggesting secondary syphilis is the most infectious stage and that earlier detection and treatment of syphilis to prevent progression to the secondary stage might improve syphilis control. Future research is needed to ascertain the contribution of shedding of T pallidum from non-lesion sites to transmission of syphilis.
Australian National Health and Medical Research Council.
梅毒传播正在增加，确切的梅毒螺旋体如何从人传人是不清楚的。我们的目的是确定从潜在无症状部位传播苍白密螺旋体的频率，以及在男男性行为者（MSM）中，感染的哪个阶段最常发生苍白密螺旋体脱落，因为他们不成比例地受到梅毒的影响。
我们在澳大利亚墨尔本性健康中心（墨尔本，维多利亚州，澳大利亚）招募了 MSM 进行了一项前瞻性、横断面研究。如果男性年龄在 18 岁或以上，报告在过去 12 个月内与男性发生性行为，并且实验室确认原发性、二期或早期潜伏梅毒符合澳大利亚的定义，则有资格参与。原发性和二期梅毒病变部位用拭子擦拭，非病变部位用口腔冲洗、口腔拭子、肛门拭子、尿液和精液采集样本。使用针对 polA（病变和非病变样本）和 47 kDa（仅非病变样本）基因靶标的 PCR 检测法检测 T 苍白密螺旋体。主要结局是从潜在无症状部位（即口腔、肛门、尿道和精液）检测到 T 苍白密螺旋体的男性比例。
2015 年 11 月 30 日至 2019 年 5 月 23 日，筛查了 246 名 MSM 以确定其纳入标准，其中 200 名血清学确诊为早期梅毒，并纳入了研究：54 名（27%）的 200 名患有原发性梅毒，93 名（47%）患有二期梅毒，53 名（27%）患有早期潜伏梅毒。通过口腔冲洗或口腔病变拭子，或两者兼用，在 200 名男性中检测到 48 名（24%；95%CI 18.3-30.5）的 T 苍白密螺旋体 DNA，其中 24 名男性没有口腔病变。与其他疾病阶段相比，在患有二期梅毒的男性中，口腔 T 苍白密螺旋体检测最为常见（93 名男性中有 41 名[44%]，107 名男性中有 7 名[7%]；p<0.0001），与梅毒快速血浆反应素滴度为 1/64 或更高的男性相比，滴度较低的男性（117 名男性中有 37 名[32%]，83 名男性中有 11 名[13%]；p=0.0026）。在有可用样本的 196 名男性中，通过肛门拭子或肛门病变拭子，或两者兼用，检测到 45 名（23.0%；95%CI 17.3-29.5）的 T 苍白密螺旋体，其中 10 名男性没有肛门病变。此外，在 198 名男性的尿液样本中检测到 12 名（6.1%，3.2-10.3）的 T 苍白密螺旋体，在 50 名提供样本的男性的精液样本中检测到 6 名（12.0%，4.5-24.3）。在 93 名患有二期梅毒的男性中，69 名（74%）在任何部位检测到 T 苍白密螺旋体，24 名（26%）在两个或更多不同部位检测到 T 苍白密螺旋体。在 54 名患有原发性梅毒的男性中，49 名（91%）在任何部位检测到 T 苍白密螺旋体，11 名（20%）在两个或更多不同部位检测到 T 苍白密螺旋体。在 53 名患有早期潜伏梅毒的男性中，4 名（8%）在任何部位检测到 T 苍白密螺旋体，没有人在两个或更多不同部位检测到 T 苍白密螺旋体。
在患有早期梅毒的 MSM 中，可从潜在无症状部位发现未识别的苍白密螺旋体脱落，在二期梅毒中最为常见，这表明二期梅毒是最具传染性的阶段，更早发现和治疗梅毒以防止进展为二期梅毒可能会改善梅毒的控制。需要进一步研究来确定非病变部位苍白密螺旋体脱落对梅毒传播的贡献。
澳大利亚国家卫生和医学研究委员会。
