Michael Marks
@drmichaelmarks.bsky.social
NIHR Research Professor
Professor of Medicine at LSHTM.
Lead for Integrated Academic Training at LSHTM.
Consultant in Infectious Diseases at UCLH.
Syphilis & STIs, Neglected Tropical Diseases, Emerging Infectious Diseases, Group A Strep, Pragmatic Trials
Professor of Medicine at LSHTM.
Lead for Integrated Academic Training at LSHTM.
Consultant in Infectious Diseases at UCLH.
Syphilis & STIs, Neglected Tropical Diseases, Emerging Infectious Diseases, Group A Strep, Pragmatic Trials
Two syphilis/STI related UK PhD Studentships with our group:
Evaluating near-patient syphilis tests with @uclglobalhealth.bsky.social inyurl.com/aw9sapma deadline 5th Dec 2025
Mathematical models to understand partner notification tinyurl.com/2re7xasj deadline 14th Jan 2026
Please do share
Evaluating near-patient syphilis tests with @uclglobalhealth.bsky.social inyurl.com/aw9sapma deadline 5th Dec 2025
Mathematical models to understand partner notification tinyurl.com/2re7xasj deadline 14th Jan 2026
Please do share
November 10, 2025 at 9:52 AM
Two syphilis/STI related UK PhD Studentships with our group:
Evaluating near-patient syphilis tests with @uclglobalhealth.bsky.social inyurl.com/aw9sapma deadline 5th Dec 2025
Mathematical models to understand partner notification tinyurl.com/2re7xasj deadline 14th Jan 2026
Please do share
Evaluating near-patient syphilis tests with @uclglobalhealth.bsky.social inyurl.com/aw9sapma deadline 5th Dec 2025
Mathematical models to understand partner notification tinyurl.com/2re7xasj deadline 14th Jan 2026
Please do share
A beautiful example of why when assessing growth of a pathogen in a cell culture line that you need to know if the drug is actually just killing the cell line.
For example T.pallidum doesn't grow in culture when you use ivermectin BUT that's because ivermectin is killing the cell line.
For example T.pallidum doesn't grow in culture when you use ivermectin BUT that's because ivermectin is killing the cell line.
October 22, 2025 at 3:03 AM
A beautiful example of why when assessing growth of a pathogen in a cell culture line that you need to know if the drug is actually just killing the cell line.
For example T.pallidum doesn't grow in culture when you use ivermectin BUT that's because ivermectin is killing the cell line.
For example T.pallidum doesn't grow in culture when you use ivermectin BUT that's because ivermectin is killing the cell line.
There is exciting progress in identifying human cell lines which could replace rabbit cells in the culture model & could therefore more accurately recapitulate human syphilis infection.
October 22, 2025 at 2:53 AM
There is exciting progress in identifying human cell lines which could replace rabbit cells in the culture model & could therefore more accurately recapitulate human syphilis infection.
We can use the in-vitro cultivation system to explore the pathogenesis of T.pallidum.
This is helping us understand the interactions between epithelial cells and the pathogen which is critical to transmission and pathogenesis.
Slowly slowly itching towards vaccines...
This is helping us understand the interactions between epithelial cells and the pathogen which is critical to transmission and pathogenesis.
Slowly slowly itching towards vaccines...
October 22, 2025 at 2:49 AM
We can use the in-vitro cultivation system to explore the pathogenesis of T.pallidum.
This is helping us understand the interactions between epithelial cells and the pathogen which is critical to transmission and pathogenesis.
Slowly slowly itching towards vaccines...
This is helping us understand the interactions between epithelial cells and the pathogen which is critical to transmission and pathogenesis.
Slowly slowly itching towards vaccines...
The schema developed by Sheila Lukehart (queen of syphilis immunology) highlights the key role of cellular immune responses alongside humoral responses in controlling and clearing T.pallidum.
October 22, 2025 at 12:21 AM
The schema developed by Sheila Lukehart (queen of syphilis immunology) highlights the key role of cellular immune responses alongside humoral responses in controlling and clearing T.pallidum.
Kicking off day 3 Shanghai Syphilis Symposium.
There is still a huge amount we can learn from the historic studies to inform our understanding of syphilis immunology and vaccine development.
There is still a huge amount we can learn from the historic studies to inform our understanding of syphilis immunology and vaccine development.
October 22, 2025 at 12:11 AM
Kicking off day 3 Shanghai Syphilis Symposium.
There is still a huge amount we can learn from the historic studies to inform our understanding of syphilis immunology and vaccine development.
There is still a huge amount we can learn from the historic studies to inform our understanding of syphilis immunology and vaccine development.
BPG is made up of lots of crystals of penicillin bound to Benzathine. These slowly release penicillin into the blood - so we have a long period of absorption from IM into the blood and then a short elimination half life in the circulation.
October 21, 2025 at 6:54 AM
BPG is made up of lots of crystals of penicillin bound to Benzathine. These slowly release penicillin into the blood - so we have a long period of absorption from IM into the blood and then a short elimination half life in the circulation.
The lack of evidence means there is massive variation around the world in how asymptomatic infants with congenital syphilis are managed globally.
We need clearer guidelines informed by well done diagnostic and therapeutic studies.
We need clearer guidelines informed by well done diagnostic and therapeutic studies.
October 21, 2025 at 6:41 AM
The lack of evidence means there is massive variation around the world in how asymptomatic infants with congenital syphilis are managed globally.
We need clearer guidelines informed by well done diagnostic and therapeutic studies.
We need clearer guidelines informed by well done diagnostic and therapeutic studies.
At one end of the congenital syphilis spectrum are those infants who have symptomatic disease. These children can be severely unwell and we need drugs that can be easily and safely administered to sick neonates.
October 21, 2025 at 6:38 AM
At one end of the congenital syphilis spectrum are those infants who have symptomatic disease. These children can be severely unwell and we need drugs that can be easily and safely administered to sick neonates.
There remains a depressingly high gap in many LMIC settings between uptake of HIV testing and syphilis testing in Antenatal Care.
And it's not an issue of cost because this is a cheap and hugely cost effective intervention. It's an issue around political will, prioritisation and sustained support.
And it's not an issue of cost because this is a cheap and hugely cost effective intervention. It's an issue around political will, prioritisation and sustained support.
October 21, 2025 at 4:44 AM
There remains a depressingly high gap in many LMIC settings between uptake of HIV testing and syphilis testing in Antenatal Care.
And it's not an issue of cost because this is a cheap and hugely cost effective intervention. It's an issue around political will, prioritisation and sustained support.
And it's not an issue of cost because this is a cheap and hugely cost effective intervention. It's an issue around political will, prioritisation and sustained support.
Introducing a new diagnostic test is not enough to address issues - for syphilis RDTs even though they gave a quicker test turn around it required a full health system intervention for that to be accompanied by an increased uptake of Syphilis treatment
October 21, 2025 at 4:41 AM
Introducing a new diagnostic test is not enough to address issues - for syphilis RDTs even though they gave a quicker test turn around it required a full health system intervention for that to be accompanied by an increased uptake of Syphilis treatment
Fundamental health system barriers remain as the major challenge to the implementation of diagnostics. If we don't fix this then no matter how good your new syphilis test is you will still run in to major road blocks in implementing and improving care pathways.
October 21, 2025 at 4:30 AM
Fundamental health system barriers remain as the major challenge to the implementation of diagnostics. If we don't fix this then no matter how good your new syphilis test is you will still run in to major road blocks in implementing and improving care pathways.
Pregnant women with syphilis are also shedding from their mucosa in a similar fashion to what has been demonstrated in MSM populations.
October 21, 2025 at 3:58 AM
Pregnant women with syphilis are also shedding from their mucosa in a similar fashion to what has been demonstrated in MSM populations.
Neurosyphilis criteria vary from country to country. A classic example of the absence of a reference standard to guide diagnostic pathways & inform management.
October 21, 2025 at 3:33 AM
Neurosyphilis criteria vary from country to country. A classic example of the absence of a reference standard to guide diagnostic pathways & inform management.
We can leverage social network structure to distribute self-testing kits to contacts & there is evidence this is a more effective method than simply asking individuals to refer their contacts for facility based testing.
October 21, 2025 at 3:14 AM
We can leverage social network structure to distribute self-testing kits to contacts & there is evidence this is a more effective method than simply asking individuals to refer their contacts for facility based testing.
There are multiple different ways we can deliver syphilis serological testing. There is good RCT data that self testing models can result in an increase in the uptake of testing - especially amongst first time testers - and (in China at least) was cheaper than facility based testing.
October 21, 2025 at 3:11 AM
There are multiple different ways we can deliver syphilis serological testing. There is good RCT data that self testing models can result in an increase in the uptake of testing - especially amongst first time testers - and (in China at least) was cheaper than facility based testing.
Rapid clearance of T.pallidum from non-lesion mucosal sites following treatment - so regardless of importance for transmission treatment will be highly effective at rendering individuals non-infectious.
October 21, 2025 at 2:58 AM
Rapid clearance of T.pallidum from non-lesion mucosal sites following treatment - so regardless of importance for transmission treatment will be highly effective at rendering individuals non-infectious.
Highlighting that amongst asymptomatic individuals there can still be a lot of mucosal shedding of T.pallidum. Can we use this to inform staging of clinical cases? What does it mean for transmission dynamics? Lots still to learn about this.
October 21, 2025 at 2:53 AM
Highlighting that amongst asymptomatic individuals there can still be a lot of mucosal shedding of T.pallidum. Can we use this to inform staging of clinical cases? What does it mean for transmission dynamics? Lots still to learn about this.
A reminder that the clinical spectrum of Congenital Syphilis is wide and that there are distinct and only partly overlapping requirements for diagnostic needs in each place.
Unlikely a single test can answer all these needs.
Unlikely a single test can answer all these needs.
October 21, 2025 at 12:22 AM
A reminder that the clinical spectrum of Congenital Syphilis is wide and that there are distinct and only partly overlapping requirements for diagnostic needs in each place.
Unlikely a single test can answer all these needs.
Unlikely a single test can answer all these needs.
Day 2 of the Shanghai International Syphilis Symposium. Bridget Freyne highlighting the inadequacies of current surveillance definitions and mechanisms for congenital syphilis.
Algorithms are either to complex for LMIC implementation OR likely result in over investigation in HICs.
Algorithms are either to complex for LMIC implementation OR likely result in over investigation in HICs.
October 21, 2025 at 12:13 AM
Day 2 of the Shanghai International Syphilis Symposium. Bridget Freyne highlighting the inadequacies of current surveillance definitions and mechanisms for congenital syphilis.
Algorithms are either to complex for LMIC implementation OR likely result in over investigation in HICs.
Algorithms are either to complex for LMIC implementation OR likely result in over investigation in HICs.
There are a series of gaps that need to be addressed if we want to identify viable alternative therapeutics to benzathine penicillin for syphilis treatment.
October 20, 2025 at 7:17 AM
There are a series of gaps that need to be addressed if we want to identify viable alternative therapeutics to benzathine penicillin for syphilis treatment.
We also need alternative drugs for several different manifestations of syphilis AND also think about how we can improve partner notification and treatment. We know poor partner notification uptake is associated with worse pregnancy outcomes - tackling this point is especially challenging.
October 20, 2025 at 7:02 AM
We also need alternative drugs for several different manifestations of syphilis AND also think about how we can improve partner notification and treatment. We know poor partner notification uptake is associated with worse pregnancy outcomes - tackling this point is especially challenging.
The @who.int recently published global STI research priorities - better tests and very importantly implementation research on their optimal deployment was the number one identified priority.
October 20, 2025 at 6:58 AM
The @who.int recently published global STI research priorities - better tests and very importantly implementation research on their optimal deployment was the number one identified priority.
What are the evidence gaps we need to address to move forward the development of syphilis vaccines.
We really need to understand some fairly basic elements
- What does protection look like
- Who do we need to vaccinated for maximum impact
- Which technologies should we leverage for vaccine design
We really need to understand some fairly basic elements
- What does protection look like
- Who do we need to vaccinated for maximum impact
- Which technologies should we leverage for vaccine design
October 20, 2025 at 6:22 AM
What are the evidence gaps we need to address to move forward the development of syphilis vaccines.
We really need to understand some fairly basic elements
- What does protection look like
- Who do we need to vaccinated for maximum impact
- Which technologies should we leverage for vaccine design
We really need to understand some fairly basic elements
- What does protection look like
- Who do we need to vaccinated for maximum impact
- Which technologies should we leverage for vaccine design
Highlighting the all too familiar story that pregnant women and children are often left out of treatment studies & the regulatory framework is often not supportive of addressing this critical gap.
October 20, 2025 at 4:35 AM
Highlighting the all too familiar story that pregnant women and children are often left out of treatment studies & the regulatory framework is often not supportive of addressing this critical gap.