Interests

Infectious Disease Epidemiology

  • Quantification of transmission dynamics and control
  • Theoretical framework construction
  • Bayesian Inference
  • COVID-19
  • Mpox (monkeypox)

My research work revolves around mathematical formulation of infectious disease dynamics drawing upon state-of-the-art mathematical/statistical/computational methodologies to comprehensively grasp the intricacies of transmission dynamics across various scales, thereby contributing to public health concerns.

In the case of directly transmitted diseases, each observed case is intertwined with its infector, creating what we term as dependent happenings. Consequently, there arises a necessity to reconstruct transmission dynamics through mathematical models that account for these non-i.i.d. settings.

My primary interest lies in quantifying natural history, transmission dynamics and control such as non-pharmaceutical interventions, vaccine strategy, etc. Additionally I aim to construct a robust theoretical framework, often through the lens of Bayesian framework.




Recent activity

  • 15.Feb.2024. Updated this website.
  • 7.Jan.2024. Our paper published in Epidemics has become the most downloaded article, having garnered interest from many readers!
  • 28.Dec.2023. New paper (preprint) is out in medRxiv.
  • 31.Oct.2023. Our paper on the estimation of waning vaccine effectiveness without relying on fine-scale dataset is published in Epidemics (1st authored).
  • 8.Oct.2023. Our study about global transmission dynamics of mpox is out on medRxiv. I contributed to this study as the second author. :
  • 4.Aug.2023. Had a research meeting in Tropical Medicine and Global Health, Nagasaki University (other attendees:Akira Endo, Alexis Robert, Sung-mok Jung, Fuminari Miura, Arata Hidano, Toshiaki Asakura).
  • 31.Jul.2023. Involved in the short course of "Introduction to infectious disease epidemiology and modelling" in School of Tropical Medicine and Global Health, Nagasaki University, Japan as a teaching assistant (24/07-31/07).
  • 17.Jun.2023. Our paper on mpox spread is accepted in The Journal of Infectious Diseases. :
  • 9.May.2023. I participated in research consortium meeting, Brussels, 6-9 May 2023 (other attendees: Akira Endo, Sung-mok Jung, Fuminari Miura, Miina Yanagihara, Toshiaki Asakura).
  • 25.Apr.2023. I was featured in a Japanese magazine titled "Japanese Scientists in Science 2022".
  • 16.Nov.2022 New paper (preprint) is out in medRxiv. I led this study as a first author:
  • This is a follow-up study of our earlier work on monkeypox epidemiology (Endo et al. 2022. Science) that looks at why cases are now declining in may affected areas. In a nutshelll, we suggested that accumulation of infection-derived immunity in heavy-tailed sexual contact networks can explain a apparent slowdown in growth of cases.
  • 24.Sep.2022. Listed as one of Contributors to UKHSA-JUNIPER MPX Network Modelling Seminar where my leading research and its findings were introduced:
  • 22.Sep.2022. Second-authoring paper is now out in Science as first release:
  • We suggested that the rapid growth of the current monkeypox outbreak is likely driven by a small fraction of men who have sex with men with many sexual partners.
  • 10.Sep.2022. It was an honour to be invited to COVID-19 pandemic conference at Nagoya and give a presentation entitled 'Impacts of vaccine, healthcare burden, and temperature on the transmissibility or virulence of COVID-19'.
  • 06.Sep.2022 My ongoing research project and results were introduced at UKHSA-JUNIPER MPX Network Modelling Seminar.
  • 24.Aug.2022 Our accepted manuscript in EID journal (early release) is now published in Volume 28, Number 9—September 2022:

Publications

Under review (†: equal contribution)

  1. Murayama H, Nishi A, Endo A. Different time scales used for sexual partner surveys pose a challenge in modelling dynamics of sexually transmitted infections. medRxiv. 2023 Jan 1;2023.12.25.23300526.
  2. Jung S†, Miura F†, Murayama H, Funk S, Wallinga J, Lessler J, Endo A. Dynamic landscape of mpox importation risks driven by heavy-tailed sexual contact networks among men who have sex with men in 2022: a mathematical modeling study. medRxiv. 2023 Jan 1;2023.10.06.23296610.

Article (†: equal contribution)

  1. Murayama H, Endo A, Yonekura S. Estimation of waning vaccine effectiveness from population-level surveillance data in multi-variant epidemics. Epidemics. 2023;100726.
  2. Murayama H, Pearson CAB, Abbott S, Miura F, Jung S, Fearon E, Funk S, Endo A. Accumulation of immunity in heavy-tailed sexual contact networks shapes mpox outbreak sizes. The Journal of Infectious Diseases. 2023 Jul 4;jiad254.
  3. Endo A, Murayama H, Abbott S, Ratnayake R, Pearson CAB, Edmunds WJ, Fearon E†, Funk S†. Heavy-tailed sexual contact networks and monkeypox epidemiology in the global outbreak, 2022. Science. 2022 Sep 25;0(0):eadd4507.
  4. Ko KY, Murayama H, Yamasaki L, Kinoshita R, Suzuki M, Nishiura H. Age-Dependent Effects of COVID-19 Vaccine and of Healthcare Burden on COVID-19 Deaths, Tokyo, Japan. Emerging Infectious Diseases. 2022;28(9).
  5. Murayama H†, Yamasaki L†, Hashizume M. The impact of temperature on the transmissibility and virulence of COVID-19 in Tokyo, Japan. Scientific Reports. 2021;11(1):24477.
  6. Murayama H, Kayano T, Nishiura H. Estimating COVID-19 cases infected with the variant alpha (VOC 202012/01): an analysis of screening data in Tokyo, January-March 2021. Theoretical Biology and Medical Modelling. 2021;18(1):13.

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