Simulating the infected population and spread trend of 2019-nCov under different policy by EIR model

Hao Xiong; Huili Yan

Much is unknown about how 2019-nCoV spreads. Most often, spread from person-to-person happens among close contacts (about 6 feet). There have been reports external icon of spread from an infected patient with no symptoms to a close contact [6] . We inferred that the epidemic could be spread by exposed (incubation) individuals. SEIR model has been widely used for modeling infectious diseases. However, it not suitable for the above spreading characters of the 2019-nCoV. We adjust this model and constructed EIR model. In which, the total population into three states: exposed (E, being infected as incubation with no symptom but with infectiousness), identified (I, being identified and quarantined without spread ability) and recovered (R, including death). In our model, exposed is assumed to be the first stage of infected individual, which is same as incubation stage, has no symptom and with infectiousness. So, we assume the exposed individuals has the possibility of infectiousness. And identified is assumed to be the second stage of infected individual, has symptom and be confirmed by hospital. So, we assume the identified individual has no ability of spreading since she/he will be pharmaceutical quarantined. Furthermore, as differential equations are not suitable for the dynamic lag relationships between exposed individuals, identified individuals and recovered individual, the new recursive formulations are presented. The dynamical process of EIR thus could be described as: