Where syphilis bacteria live and whether they can spread from symptom-free sites in women and men who have sex with women
Treponemal Shedding, Load, and Viability, in Women and Men-who-have-sex-with-women Only With Early Infectious Syphilis: Implications for Transmission
This study will test whether syphilis bacteria found on symptom-free body sites are alive and how long they can be detected in women and men who have sex with women only.
Quick facts
| Study type | Observational |
|---|---|
| Enrollment | 480 (estimated) |
| Ages | 18 Years and up |
| Sex | All |
| Sponsor | Monash University Academic / other |
| Locations | 9 sites (Melbourne, Victoria and 8 other locations) |
| Trial ID | NCT07300254 on ClinicalTrials.gov |
What this trial studies
This observational cohort will enroll adults with untreated early infectious or early latent syphilis who are cis-women, cis-men who have sex with women only, or nonbinary people with a penis who have sex with women. Researchers will collect samples from multiple anatomical sites (for example vaginal, anal, and other mucosal surfaces) and use molecular tests and viability assays to detect Treponema pallidum and determine if detected organisms are alive. Participants will be followed over time with repeat sampling to measure how long DNA and viable organisms are detectable. The study is being conducted at clinical sites in Melbourne and Shanghai and does not involve therapeutic interventions.
Who should consider this trial
Good fit: Adults (≥18) who are cis-women, cis-men who have sex with women only, or nonbinary people with a penis who have sex with women, have had at least one sexual partner in the past year, and have untreated primary, secondary, or early latent syphilis meeting the study criteria.
Not a fit: People who have already received treatment for syphilis, those without current syphilis infection, minors, or men who have sex with men are unlikely to benefit directly from participation.
Why it matters
Potential benefit: If successful, the findings could clarify hidden transmission routes of syphilis and help improve testing, prevention, and partner-notification strategies for affected people.
How similar studies have performed: Previous studies—mainly in men who have sex with men—have detected asymptomatic syphilis DNA at anatomical sites but have not definitively shown whether those bacteria are viable, so this study addresses a partly untested area.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: \- 1. Any cis-woman, cis-MSW, or nonbinary individuals with a penis who have sex with women only, (who meet all other study criteria) 2. Aged ≥18 years of age, 3. At least one sexual partner in the last 12 months 4. One of either: a. Untreated clinically suspected primary or secondary syphilis. i. Must have rash or lesion(s) clinically suggestive of early infectious syphilis infection. ii. May have positive PCR result, positive Dark-ground Microscopy result, positive syphilis serology or positive point-of-care syphilis test, but these are not necessary at the time of enrolment. b. Untreated early latent (no clinical signs indicative of primary or secondary syphilis) syphilis with positive syphilis serology or positive point-of-care test, and one or more of the following(11): i. A documented syphilis seroconversion within the prior 12 months. ii. A sustained (longer than 2 weeks) fourfold or greater increase in the titre in the prior 12 months in a person previously treated for syphilis. iii. Unequivocal symptoms of primary or secondary syphilis within the prior 12 months. iv. Contact in the prior 12 months with a sex partner who had untreated primary, secondary, or early latent syphilis. v. Documented reactive nontreponemal and treponemal tests, and the only possible exposure occurred during the previous 12 months vi. RPR/VDRL titre \>= 1:64 5. Be willing and able to complete study procedures, including physical examination 6. Receiving syphilis treatment on the day of recruitment 7. Have sufficient language proficiency to understand the requirements of the study 8. Provide informed consent as per individual site's local ethics requirements Exclusion Criteria: 1. Men, transwomen, or other people, with a penis, who have had any sexual contact, including kissing, oral sex or anal sex, with men (or any other individual with a penis) in the previous one year. 2. Individuals who have received antibiotic treatment within 1 month prior to enrolment, with the EXCEPTION of metronidazole. 3. Diagnosis of late latent syphilis (\>1 year) or latent syphilis of unknown duration.
Where this trial is running
Melbourne, Victoria and 8 other locations
- Monash University — Melbourne, Victoria, Australia (Active_not_recruiting)
- Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine — Shanghai, Shanghai Municipality, China (Not_yet_recruiting)
- Shanghai Skin Disease Hospital — Shanghai, Shanghai Municipality, China (Not_yet_recruiting)
- National Institute for Communicable Diseases — Johannesburg, South Africa (Not_yet_recruiting)
- Foundation for Professional Development — Pretoria, South Africa (Not_yet_recruiting)
- Burrell Street Clinic, Guy's and St Thomas' — London, United Kingdom (Recruiting)
- Jefferiss Clinic St Mary's Hospital, Imperial College London — London, United Kingdom (Recruiting)
- Mortimer Market Centre — London, United Kingdom (Recruiting)
- London School of Hygiene & Tropical Medicine — London, United Kingdom (Active_not_recruiting)
Study contacts
- Principal investigator: Janet Towns — Monash University
- Study coordinator: Brigid M Scally
- Email: brigid.scally@monash.edu
- Phone: +61399039300
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.