Health and Environmental Sciences

photo Hiroshi Nishiura Hiroshi Nishiura, M.D., Ph.D.btn

Among many disciplines of hygiene, we excel into infectious diseases. The team is a mixture of the variety of people with different backgrounds and also a mixture of different nationalities. Physicians, veterinarians, public health experts and other medical experts are mixed with mathematicians, statisticians, biologists, informaticians, politicians and those from other disciplines. They sometimes use completely different languages, but we enjoy that type of chaotic daily life. Only the common thread is that we work on infectious disease epidemiology, and we welcome anyone brave enough to join us!

Research and Education

Our lab excels into mathematical modeling of infectious diseases, especially statistical analysis of empirically observed data. More specifically, our research subjects are enumerated in the following.
1. Real time analysis and forecasting of emerging and re-emerging infectious disease epidemics
2. Statistical estimation of incidence and prevalence. Inference of diagnostic coverage
3. Epidemiological studies of vaccine preventable diseases
4. Modeling studies of interface between humans and environment: human-animal interface, zoonosis and environmental exposure
5. Quantification of the natural history: transmission potential, case fatality risk, incubation period, generation time and their determinants
6. Development of novel likelihood and new methodologies, especially explicit derivation of likelihood functions from semi-structured epidemiological system
We recently step into the analysis of human demographic data and epidemiology/inference of non-communicable diseases, but we limit ourselves to a small number of projects in this area. Our models and mathematical theories are drastically changed, depending on empirical data. Regardless of mathematical techniques, we aim to achieve modeling studies that can answer pressing scientific or policy-relevant questions.

Epidemiological projections of novel coronavirus infection (COVID-19) in Tokyo, 2020. Orange bars represent observed epidemic curve with known date of illness onset, and black curve shows the fitted model. Depending on different levels of intervention, resulting trajectories would vary.
Estimated effective reproduction number of novel coronavirus infection (COVID-19) in Tokyo, 2020. Yellow bars show non-parametrically back-projected date of infections. Blue line and shades show the posterior median and 95% credible intervals of the effective reproduction number, showing how many secondary cases on average were produced by a single primary case on each day.

 Recent Publications

  1. Anzai A, Kawatsu L, Uchimura K, Nishiura H. Reconstructing the population dynamics of foreign residents in Japan to estimate the prevalence of infection with Mycobacterium tuberculosis. Journal of Theoretical Biology 2020;489:110160. doi: 10.1016/j.jtbi.2020.110160.
  2. Echigoya Y, Yamaguchi T, Imamura A, Nishiura H. Estimating the syphilis incidence and diagnosis rate in Japan: a mathematical modelling study. Sexually Transmitted Infections 2020:sextrans-2019-054421. doi: 10.1136/sextrans-2019-054421.
  3. Chan YH, Nishiura H. Estimating the protective effect of case isolation with transmission tree reconstruction during the Ebola outbreak in Nigeria, 2014. Journal of the Royal Society Interface 2020;17:20200498. doi: 10.1098/rsif.2020.0498.
  4. Nishiura H, Linton NM, Akhmetzhanov AR. Serial interval of novel coronavirus (COVID-19) infections. International Journal of Infectious Diseases 2020;93:284-286. doi: 10.1016/j.ijid.2020.02.060.
  5. Linton NM, Kobayashi T, Yang Y, Hayashi K, Akhmetzhanov AR, Jung SM, Yuan B, Kinoshita R, Nishiura H. Incubation Period and Other Epidemiological Characteristics of 2019 Novel Coronavirus Infections with Right Truncation: A Statistical Analysis of Publicly Available Case Data. Journal of Clinical Medicine 2020;9:538. doi: 10.3390/jcm9020538.

Health and Environmental Sciences

Professor: Hiroshi Nishiura, M.D., Ph.D.
Associate Professor: Kouji Harada, Ph.D., MPH
Assistant Professor: Taishi Kayano, D.V.M., MSc
Assistant Professor: Tetsuro Kobayashi, M.D., MPH
Assistant Professor: Ayako Suzuki, M.D., MPH
Assistant Professor: Katsuma Hayashi, M.D.