Targeting Supercontactors for Safer Long-Term Care

Interview with Quentin J. Leclerc: PrIMAVeRa

Recently, the PrIMAVeRa project has published a significant study on the transmission of pathogens in long-term care facilities. The study’s first author, Quentin J. Leclerc, employed an individual-based model to simulate the dynamics of methicillin-resistant Staphylococcus aureus (MRSA) transmission. The findings revealed that “supercontactors” — individuals with exceptionally high numbers or long durations of contact — play a critical role in the spread of infections. Quentin J. Leclerc kindly agreed to answer our questions.

You are a mathematical modeller, how exactly do you apply those skills to AMR research?

I study the dynamics of AMR using data, equations, and computational tools. For example, I try to understand how fast bacteria spread between staff and patients in hospitals, or how millions of bacteria interact in a test tube to become more or less resistant to antibiotics over time. My main focus is estimating the impact of interventions. To what extent could the vaccination of some staff or patients prevent the spread of AMR in a hospital? Who should be targeted with improved hand washing to lead to the greatest reduction in transmission? By how much could the number of infections be reduced by a new treatment? These are the types of questions I’m trying to answer.

How does your research contribute to the fight against AMR?

By guiding the implementation of interventions against AMR, notably in healthcare settings. Through my research, I aim to help at every step of the way in this process, whether it is to identify the target population for a hypothetical vaccine or treatment, optimise existing interventions, or suggest novel, alternative strategies.

Quentin J. Leclerc is a mathematical modeller at
Institut Pasteur and Conservatoire National des Arts et Métiers, Paris.

What are some of the biggest challenges in your topic?

I would say that lack of data is the biggest challenge! Carrying on with my previous example, to understand how bacteria spread in a hospital, I need data on when patients arrive and leave, which staff are present at each time, when individuals come into contact with each other, and which bacteria each individual carries each day… Unfortunately, as you can imagine, this is a dream wish list! As a mathematical modeller, I always have to try to collect as much data as I can, for example, by talking with clinicians or epidemiologists, and come up with solutions when I’m missing some information.

This must mean that direct contact with the clinicians is critical in your research! Can you tell us more about this part of your work?

Collaboration is essential! In the context of the PrIMAVeRa project, I had the opportunity to collaborate with other mathematical modellers, clinicians and epidemiologists to collaboratively design a realistic mathematical model and evaluate the impact of monoclonal antibodies. While it can be challenging to reconcile different perspectives, it often leads to new ideas and allows us to be more confident that our work will be reliable and have an important impact on public health.

Do you have long-term goals and aspirations in the field of AMR?

I would like to collaborate with other researchers and clinicians globally to investigate new solutions against AMR. Another important goal for me is to become more involved in talking about AMR to a wider audience, whether that is members of the public or other researchers who may not yet understand how they could contribute to the fight against AMR.

In your opinion, what is the most important message for the public to understand about AMR?

Simply being aware that AMR exists, and what it means. Knowing this is much more reassuring than discovering that this problem exists only when you are suddenly confronted with it. By being aware of AMR, the public can then better understand the efforts that are being made to fight against it and support these efforts.

How do you stay motivated and passionate about your work? And what interests do you have outside of your research?

I really enjoy teaching, and I think it plays an essential part in staying motivated. While the rewards of day-to-day scientific work are generally only felt in the long term, it is incredibly motivating to spend an hour in a class and immediately see the impact this can have on students. And, as mentioned, collaborations are key to constantly hearing fresh perspectives on my work. Outside of work, when I’m not busy staring at equations on my computer, I’m most likely climbing, playing badminton… or staring at a bigger screen to play video games!

Want to know more? Take a look at other publications from PrIMAVeRa:

  • Hassoun-Kheir N, Guedes M, Arieti F, et al. Expert consensus on antimicrobial resistance research priorities to focus development and implementation of antibacterial vaccines and monoclonal antibodies. Eurosurveillance. 2024;29(47):2400212. doi:10.2807/1560-7917.ES.2024.29.47.2400212
  • Leclerc QJ, Duval A, Guillemot D, Opatowski L, Temime L. Using contact network dynamics to implement efficient interventions against pathogen spread in hospital settings: A modelling study. PLOS Medicine. 2024;21(7):e1004433. doi:10.1371/journal.pmed.1004433
  • Pezzani MD, Arieti F, Rajendran NB, et al. Frequency of bloodstream infections caused by six key antibiotic-resistant pathogens for prioritization of research and discovery of new therapies in Europe: a systematic review. Clinical Microbiology and Infection. 2024;30:S4-S13. doi:10.1016/j.cmi.2023.10.019
  • Robotham J v., Tacconelli E, Vella V, de Kraker MEA. Synthesizing pathogen- and infection-specific estimates of the burden of antimicrobial resistance in Europe for health-technology assessment: gaps, heterogeneity, and bias. Clinical Microbiology and Infection. 2024;30:S1-S3. doi:10.1016/j.cmi.2023.10.004
  • Kingston R, Vella V, Pouwels KB, et al. Excess resource use and cost of drug-resistant infections for six key pathogens in Europe: a systematic review and Bayesian meta-analysis. Clinical Microbiology and Infection. 2024;30:S26-S36. doi:10.1016/j.cmi.2023.12.013
  • Hassoun-Kheir N, Buetti N, Olivier V, et al. Targeted mupirocin-based decolonization for Staphylococcus aureus carriers and the subsequent risk of mupirocin resistance in haemodialysis patients – a longitudinal study over 20 years. Journal of Hospital Infection. 2023;135:55-58. doi:10.1016/j.jhin.2023.01.019
  • Hassoun-Kheir N, Harbarth S. Estimating antimicrobial resistance burden in Europe—what are the next steps? The Lancet Public Health. 2022;7(11):e886-e887. doi:10.1016/S2468-2667(22)00250-X
  • de Kraker MEA, Harbarth S. Global burden of antimicrobial resistance: essential pieces of a global puzzle. The Lancet. 2022;399(10344):2347. doi:10.1016/S0140-6736(22)00940-0