摘要
A novel coronavirus(COVID-19)has emerged as a global serious public health issue from December 2019.People having a weak immune system are more susceptible to coronavirus infection.It is a double challenge for people of any age with certain underlying medical conditions including cardiovascular disease,diabetes,high blood pressure and cancer etc.Co-morbidity increases the probability of COVID-19 complication.In this paper a deterministic compartmental model is formulated to understand the transmission dynamics of COVID-19.Rigorous mathematical analysis of the model shows that it exhibits backward bifurcation phenomenon when the basic reproduction number is less than unity.For the case of no re-infection it is shown that having the reproduction number less than one is necessary and sufficient for the effective control of COVID-19,that is,the disease free equilibrium is globally asymptotically stable when the reproduction threshold is less than unity.Furthermore,in the absence of reinfection,a unique endemic equilibrium of the model exists which is globally asymptotically stable whenever the reproduction number is greater than unity.Numerical simulations of the model,using data relevant to COVID-19 transmission dynamics,show that the use of efficacious face masks publicly could lead to the elimination of COVID-19 up to a satisfactory level.The study also shows that in the presence of co-morbidity,the disease increases significantly.
