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A study of epidemic model using SEIR model

SEIR 모형을 이용한 전염병 모형 예측 연구

  • Do, Mijin (Department of Statistics, Daegu University) ;
  • Kim, Jongtae (Department of Computer Science and Statistics, Daegu University) ;
  • Choi, Boseung (Department of Applied Statistics, Korea University)
  • 도미진 (대구대학교 대학원 통계학과) ;
  • 김종태 (대구대학교 전산통계학과) ;
  • 최보승 (고려대학교 응용통계학과)
  • Received : 2017.02.10
  • Accepted : 2017.03.08
  • Published : 2017.03.31

Abstract

The epidemic model is used to model the spread of disease and to control the disease. In this research, we utilize SEIR model which is one of applications the SIR model that incorporates Exposed step to the model. The SEIR model assumes that a people in the susceptible contacted infected moves to the exposed period. After staying in the period, the infectee tends to sequentially proceed to the status of infected, recovered, and removed. This type of infection can be used for research in cases where there is a latency period after infectious disease. In this research, we collected respiratory infectious disease data for the Middle East Respiratory Syndrome Coronavirus (MERSCoV). Assuming that the spread of disease follows a stochastic process rather than a deterministic one, we utilized the Poisson process for the variation of infection and applied epidemic model to the stochastic chemical reaction model. Using observed pandemic data, we estimated three parameters in the SIER model; exposed rate, transmission rate, and recovery rate. After estimating the model, we applied the fitted model to the explanation of spread disease. Additionally, we include a process for generating the Exposed trajectory during the model estimation process due to the lack of the information of exact trajectory of Exposed.

질병 확산 모형은 질병의 확산 과정을 모형화 함으로써 질병이 발생하고 퍼지는 시간 내에서 통제하기 위하여 활용하고자 하는 모형이다. 본 연구에서는 질병 확산 모형의 가장 대표적인 SIR 모형에 기본적인 확장 접근을 하여 접촉군 (exposed)이라는 단계를 추가한 SEIR 모형을 이용하여 모형 구축을 하였다. 이 모형은 감염 대상군 (susceptible)의 사람들이 질병에 노출 된 잠복기를 거쳐 일정 시간이 경과한 후 감염되어 감염군 (infected)으로 이동한 후 다시 회복군 (removed)으로 이동하는 모형이다. 이와 같이 질병에 감염된 후 감염력이 생기는 잠복기가 있는 경우에 연구에 활용될 수 있다. 본 연구에서는 2015년 국내에서 발생한 메르스 코로나바이러스 (Middle East respiratory syndrome coronavirus; MERS CoV)에 의한 호흡기 감염증 자료를 수집하였다. 질병의 확산 과정이 결정적이 아닌 확률적인 흐름을 따른다고 가정하여 포아송 확률과정을 따른다고 보고 확률적 화학반응 모형을 이용하여 모형을 구축하였다. 모형을 구현하기 위해서 SEIR 모형의 세 모수인 질병에 노출된 정도를 나타내는 접촉률 (exposed rate), 질병의 감염 정도를 나타내는 감염률 (transmission rate), 질병의 회복정도를 나타내는 회복률 (recovery rate)를 추정함으로써, SEIR 모형에 적합하고 전염병 확산에 대한 예측을 수행하였다. 또한 접촉군이 정확하게 관찰되지 않을 부분을 보완하기 위하여 접촉군을 생성하는 과정을 전체 모형 구축 과정에 추가하였다.

Keywords

References

  1. Assiri, A., McGeer, A., Perl, T., Price, C., Rabeeah, A., Cummings, D., Alabdullatif, Z., Assad, M., Almulhim, A., Makhdoom, H., Madani, H., Alhakeem, R., Al-Tawfiq, J., Cotten, M., Watson, S., Kellam, P., Zumla, A., and Memish, Z. (2013). Hospital outbreak of Middle East respiratory syndrome coronavirus. The New England Journal of Medicine, 369, 407-416. https://doi.org/10.1056/NEJMoa1306742
  2. Andersson, H. and Britton, T. (2000). Stochastic epidemic models and their statistical analysis, Springer, New York.
  3. Boys, R., Wilkinson, D. and Kirkwood, T. (2008). Bayesian inference for a discretely observed stochastic kinetic model. Statisics and Computing, 18, 125-135. https://doi.org/10.1007/s11222-007-9043-x
  4. Choi, B. (2015). An estimation method for stochastic reaction model. Journal of the Korean Data & Information Science Society, 26, 813-826. https://doi.org/10.7465/jkdi.2015.26.4.813
  5. Choi, B. and Rempala, G. A. (2012). Inference for discretely observed stochastic kinetic networks with applications to epidemic modeling. Biostatistics, 13, 153-165. https://doi.org/10.1093/biostatistics/kxr019
  6. Gelman, A. and Rubin, D. B. (1992). Inference from iterative simulation using multiple sequences. Statistical Science, 7, 457-472. https://doi.org/10.1214/ss/1177011136
  7. Gillespie, D. T. (1977). Exact stochastic simulation of coupled chemical reactions. The Journal of Physical Chemistry, 81, 2340-2361. https://doi.org/10.1021/j100540a008
  8. Hwang, N. A., Jeong, B. Y., Lim, Y. C. and Park, J. S. (2007). Diseases data analysis using SIR nonlinear regression model. Journal of The Korean Data Analysis Society, 9, 49-59.
  9. Kermack, W. O. and McKendrick, A. G. (1927). A contribution to the mathematical theory of epidemics. Proceedings of the Royal Society A: Mathematical Physical and Engineering Sciences, 115, 700-721. https://doi.org/10.1098/rspa.1927.0118
  10. Kim, C. S. (2010). Development and evaluation of influenza confinement strategy using mathematical estimating model, Final report, Korea Centers for Disease Control & Prevention, Osong.
  11. Korea Centers for Disease Control and Prevention (2015). Middle east repiratory syndrome coronavirus outbreak in the republic of Korea, 2015. Osong Public Health Research Perspect, 6, 269-278. https://doi.org/10.1016/j.phrp.2015.08.006
  12. Lee, J. H., Murshed, M. S. and Park, J. S. (2009). Estimation of infection distribution and prevalence number of Tsutsugamushi fever in Korea. Journal of the Korean Data & Information Science Society, 20, 149-158.
  13. Lim, Y., Do, M. and Choi, B. (2016). A construction of susceptible - infected - removed model using Korean MERS pandemic data. Journal of the Korean Data Analysis Society, 18, 105-115.
  14. Neurirth, E. and Arganbright, D. (2004). The active modeler: Mathematical modeling with Microsoft Excel, Tnomson Brooks/Cde, Belmont.
  15. Ross, R. (1911). The prevention of Malaria, 2nd Eds., John Murray, London.
  16. Ryu, S. and Choi, B. (2015). Development of epidemic model using the stochastic method. Journal of the Korean Data & Information Science Society, 26, 301-312. https://doi.org/10.7465/jkdi.2015.26.2.301
  17. Schwartz, E., Choi, B. and Rempala, G. A. (2015). Estimating epidemic parameters: Application to HINI pandemic data. Mathematical Biosciences, 270, 198-203. https://doi.org/10.1016/j.mbs.2015.03.007
  18. Seo, M. and Choi, B. (2015). An estimation method for stochastic epidemic model. Journal of the Korean Data Analysis Society, 17, 1247-1259.