In this paper, we use a susceptible-exposed-infectious-removed (SEIR) model to describe the dynamics of influenza A (H1N1) in mainland China. First, we develop a method for estimating the reproduction number R from the exponential growth rate r of the cumulative incidence data which gives an estimate of the R value as 1.55. This method is then extended to estimate the time-dependent effective reproduction number Rt from the weekly case-reporting data. Rt fluctuates significantly during the epidemic, showing a decreasing trend as quarantine and vaccination take effect, and it eventually drops below 1 by the end of 2009. Our modeling results suggest that the early implementation of intervention strategies were vital in preventing large-scale outbreaks of H1N1 disease in China in 2009.
H1N1 reproduction number containment strategy
Yong Zhang Liqun Fang Yan Gao Xiangming Xiao Michael J Tildesley
School of Mathematical Sciences, Beijing Normal University, Beijing,100875, China State Key Laboratory of Pathogens and Biosecurity,Beijing Institute of Microbiology and Epidemiology State Key Laboratory for Molecular Virology and Genetic Engineering, National Institute for Viral Di Department of Botany and Microbiology, Center for Spatial Analysis,University of Oklahoma,Norman,Okl Centre for Immunity,Infection and Evolution,Ashworth Laboratories,University of Edinburgh,Kings Buil