Impact of Partial lockdown on Time-Dependent Effective Reproduction Number of COVID-19 infection in Ghana: Application of change point analysis

In 2020, the world was plagued with COVID-19 which was first identified in Wuhan, China in November 2019. During the early phase of the pandemic with no known treatment and WHO-approved vaccines, most government and public health officials were pushing for non-pharmaceutical intervention in trying to curb the spread of COVID-19. One such intervention is the restriction on movement to reduce social mixing. However, the economic cost of locking down cities especially in developing countries is unbearable as most of these countries are running economies that were on life support before the COVID-19 pandemic. We analyze the daily COVID-19 cases in Ghana to evaluate whether there was a significant change in transmission of COVID-19 after the partial lockdown of the two main cities (Kumasi and Accra) was lifted. The results showed that there was no increase in the transmissibility of COVID-19 after the partial lockdown was lifted. Contrary to the expectation that transmissibility will increase after lifting the partial lockdown, there was a reduction of the time-dependent reproduction ratio from 3.17 to 1.23.