Department of Mathematics, Wilfrid Laurier University
Speaker: Professor Xiaomei Feng, Yuncheng University, China
Title: The Impact of Virus Mutation in Chikungunya Transmission: A Mathematical Modeling
Abstract: Chikungunya is caused by the Chikungunya virus (CHIKV) and transmitted to humans by infected Aedes mosquitoes. Although mainly reported in Africa, Asia and the Indian subcontinent before 2013, it is now becoming a global public problem. Particularly, it caused major outbreaks in several countries of the Americas in 2015. Moreover, recent evidence indicates that CHIKV has a new variant, which was found in La Reunion, Italy, China. The role of the new variant on the spread and control of CHIKV infection is not clear. In this paper, we introduce a mathematical model to investigate the impact of virus mutation on the spread and control of CHIKV. Then we use the model to fit the CHIKV epidemic data from Italy in 2007, which indicates that the outbreak of CHIKV in Italy might be caused by the mutant strain. By comparing with a previous model without the mutation strain, it is founded that there is an underestimate of the basic reproduction number if virus mutation is not considered. The basic reproduction number is estimated to be R0 = 2.1 [95% CI: 2.5129-2.6225]. The sensitivity analysis indicates that R0 is mostly sensitive to the biting rate and mortality rate of mosquitoes. Moreover, for the two characteristics of the mutant strain, the shortened extrinsic incubation period has no significance influence on R0, but the probability of transmission from mosquitoes with mutant strain to humans does. Combining with the mutation rate, it implies that mosquitoes with mutant strain have more transmission ability which will increase the risk of infection and epidemic size.