Author(s)

Isack E. Kibona, Cuihong Yang

School of Mathematics and Science, Central China Normal University (CCNU), Wuhan, China.

An SIR model of Zika virus (ZIKV) spread is formulated that includes ZIKV infections to newborns. Analytically, the model has one disease free and one endemic equilibrium point. The free one is stable for some conditions when R₀ and unstable when R₀>1. In Brazil, when R₀≈2>1 ZIKV infections expand and for R₀ = 0.875<1 diminishes. There were 67 micro-cephaly babies confirmed to have linked with ZIKV infections as of February 2016 in Brazil. Simulation predicts that the number rose to not less than 2100 in January 2017 and expected to increase around 4350 by January 2018 if not controlled. Simulation of the endemic equilibrium point indicates that there is more number of individuals in the recovered class than in the infectious class contrasting the initial state of the epidemic. This recovered class serves as a silent natural resistance against spread of the epidemic. Measures to control ZIKV infections have been suggested by analyzing parameters linked to transmission. The base is controlling basic reproduction number (R₀) of the model. There are parameters for human-mosquito transmission and some for sexual-transmission factor. It appears that controlling spread of ZIKV infections by human-mosquito transmission may greatly reduce the value of R₀.

ZIKV, SIR Model, Microcephaly, Stability Analysis, Simulations

Kibona, I. and Yang, C. (2017) SIR Model of Spread of Zika Virus Infections: ZIKV Linked to Microcephaly Simulations. Health, 9, 1190-1210. doi: 10.4236/health.2017.98086.