Model introduction
This is an SIR model that simulates the potential COVID outbreak that can happen in Burnie, Tasmania after the positive case reported on October 2nd 2021, which incorporates three parts: Susceptible – Infectious – Recovered Looping model, government’s health policy that will affect each phase of the SIR process, and the potential economy that will affect people’s behaviours and thus influence the effectiveness of government’s public policy.
For instance, the values of variables deciding the inflection rate are influenced by actions taken to control the situation, such as through the quarantine of those infected, social distancing, travel bans, and personal isolation and protection strategies. Conversely, the magnitude of the problem at various points in time will also influence the magnitude of the response to control the situation.
Assumptions
1. The population is assumed to be homogeneous and well-mixed. And there is no significant change on the total population due to births and deaths.
2. Once lockdown is lifted, no further imported cases are assumed to occur.
3. Super spreader events are not explicitly considered.
4. The interaction among states is assumed to be implicit.
5. All confirmed cases would go to quarantine, and 90% of their contacts can be traced.
6. Contact tracing and testing capacity is sufficient.
Insights
Ideally, both one-way scenario analysis and two-way scenario analysis (amount change in one/two variables each time) will be conducted to find out the variable that has the greatest impact on getting new cases. Insights below can be gained:
1.What happens if people are more/less likely to pass on infection, through washing their hands and sneeze into their elbows (infection rate affected by people’s behaviours that will further induced by government’s policies)
2. How vaccination rate will affect the development of positive cases
3. What if the structure of the contact network changes (extent to which school, workplace and restaurants is shut down)
4. How growth rate is sensitive to the duration of illness and probability of infection
