RecruitingOBSERVATIONAL

Treponemal Shedding, Load, and Viability, in Women and Men-who-have-sex-with-women-only With Early Infectious Syphilis: Implications for Transmission

This research aims to understand how syphilis is passed from person to person. Currently, it's not fully clear if syphilis bacteria found in body areas without obvious sores are alive and infectious. We call this 'asymptomatic' shedding. Most previous studies have focused on men who have sex with men, so there's less information about women and men who only have sex with women. This study will investigate if the syphilis bacteria found in various parts of the body are alive and capable of causing infection. It will also look at how long these bacteria remain detectable and active. This information is crucial for better preventing syphilis transmission, especially in groups where current knowledge is limited.

At a glance

Status

Recruiting

Sponsor

Monash University

Enrolment target

480

Start

02 Dec 2025

Estimated completion

31 Dec 2028

Syphilis

What is this study about?

This study is trying to understand more about how syphilis spreads. Syphilis is a sexually transmitted infection, and while we know it's passed through sexual contact, it's not always clear how. Sometimes, people can have the syphilis bacteria in their body in places where there are no obvious sores or symptoms, which is called 'asymptomatic' infection. This study wants to find out if these bacteria, when found without symptoms, are actually alive and able to infect another person. Knowing this is really important for preventing the spread of syphilis, as it could mean the infection can be passed on even when there are no visible signs.

Most research in this area has focused on gay and bisexual men. However, there's not much information about women, or men who only have sex with women, particularly regarding how the infection might be present in areas like the anus or vagina without symptoms. This study aims to fill that gap by focusing on these groups.

The researchers will explore three main things: where the syphilis bacteria can be found in women and men who only have sex with women, whether these bacteria are alive and can cause infection in symptom-free areas, and how long these bacteria remain detectable and active. This will help doctors and public health experts understand the different ways syphilis can be transmitted and develop better ways to prevent its spread.

Key takeaways

Exploring syphilis spread from symptom-free areas.
Focusing on women and men who only have sex with women.
Checking if syphilis bacteria found are alive and infectious.
Aims to improve syphilis prevention strategies.
Participation involves providing extra samples during routine clinic visits.

Who may be eligible?

This study is looking for women, men who only have sex with women (this includes cisgender men and nonbinary individuals with a penis), who are aged 18 or over. You must have had at least one sexual partner in the last year. You also need to have suspected or confirmed early syphilis that hasn't been treated yet. This could mean you have a rash or sores typical of early syphilis, or have been diagnosed with early latent syphilis (meaning you have the infection but no obvious symptoms).

You wouldn't be able to take part if you are a man, a transwoman, or another person with a penis, who has had any sexual contact with men in the last year. You also can't participate if you've been given antibiotics in the month before joining the study.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you at least 18 years old?
Are you a woman or a man who only has sex with women (or a nonbinary individual with a penis who only has sex with women)?
Have you been diagnosed with, or have symptoms of, early syphilis that hasn't been treated yet?
Have you NOT had sex with men, or any other person with a penis, in the last year?
Have you NOT taken antibiotics in the last month?

Answer every question to see your result.

What does participation involve?

If you decide to take part, you'll be asked to provide some extra samples during your routine clinic visit for syphilis diagnosis. This will involve additional swabs from your mouth and anus, a urine sample, and if relevant, a vaginal swab or a swab from your penis skin. You'll also have a blood sample taken. These extra samples are in addition to the standard tests done for syphilis diagnosis. There are no specific medications given as part of this study, as it is observational, meaning the researchers are just watching and collecting information. The total duration of your involvement will be around the time of your routine clinic visit for diagnosis and treatment.

Potential risks and benefits

Potential benefits of taking part include contributing to a better understanding of how syphilis spreads, which could help improve prevention efforts for everyone. The risks are minimal and mainly involve the slight discomfort from additional swabs and blood samples, similar to routine clinic procedures. You are free to withdraw from the study at any time without it affecting your medical care.

Locations (9)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

Monash University
Verified postcode
Melbourne, Australia· Active not recruiting
Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine
Verified postcode
Shanghai, China· Not yet recruiting
Shanghai Skin Disease Hospital
Verified postcode
Shanghai, China· Not yet recruiting
National Institute for Communicable Diseases
Verified postcode
Johannesburg, South Africa· Not yet recruiting
Foundation for Professional Development
Verified postcode
Pretoria, South Africa· Not yet recruiting
Burrell Street Clinic, Guy's and St Thomas'
Verified postcode
London, United Kingdom· Recruiting
Jefferiss Clinic St Mary's Hospital, Imperial College London
Verified postcode
London, United Kingdom· Recruiting
Mortimer Market Centre
Verified postcode
London, United Kingdom· Recruiting
London School of Hygiene & Tropical Medicine
Verified postcode
London, United Kingdom· Active not recruiting

Common questions

What is 'asymptomatic detection'?

This means finding the syphilis bacteria in a part of the body where there are no obvious sores or symptoms of infection.

Why is it important to know if the bacteria are 'viable'?

Knowing if the bacteria are 'viable' means knowing if they are alive and able to transmit the infection. This helps to understand how the infection spreads.

Who can participate in this study?

Women and men who only have sex with women (including some nonbinary individuals) aged 18 or over, who have suspected or confirmed early syphilis and meet other specific criteria.

Will I receive any new treatment if I join?

No, this study is observational, meaning you will receive standard syphilis treatment, but no new or experimental treatments are given as part of the research.

Will this study share my personal details?

No, your personal information will be kept confidential according to ethical guidelines.

How to find out more

Brigid M Scally

brigid.scally@monash.edu +61399039300 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.