Abstract:
The SARS-CoV-2 driven infectious novel coronavirus disease (COVID-19) has been declared a pandemic by its brutal impact on the world in terms of loss on human life,
health, economy, and other crucial resources. To explore more about its aspects, we
adopted the SEIRD (Susceptible–Exposed–Infected–Recovered–Death) pandemic spread
with a time delay on the heterogeneous population and geography in this work. Focusing
on the spatial heterogeneity, epidemic spread on the framework of modeling that
incorporates population movement within and across the boundaries is studied. The
entire population of interest in a region is divided into small distinct geographical sub
regions, which interact using migration networks across boundaries. Utilizing the time
delay differential equations based model estimations, we analyzed the spread dynamics
of disease in India. The numerical outcomes from the model are validated using real
time available data for COVID-19 cases. Based on the developed model in the framework
of the recent data, we verified total infection cases in India considering the effect of
nationwide lockdown at the onset of the pandemic and its unlocking by what seemed
to be the end of the first wave. We have forecasted the total number of infection cases
in two extreme situations of nationwide no lockdown and strict lockdown scenario.
We expect that in future for any change in the key parameters, due to the regional
differences, predictions will lie within the bounds of the above mentioned extreme
plots. We computed the approximate peak infection in forwarding time and relative
timespan when disease outspread halts. The most crucial parameter, the time-dependent
generalization of the basic reproduction number, has been estimated. The impact of
the social distancing and restricted movement measures that are crucial to contain the
pandemic spread has been extensively studied by considering no lockdown scenario.
Our model suggests that attaining a reduction in the contact rate between susceptible
and infected individuals by practicing strict social distancing is one of the most effective
control measures to manage COVID-19 spread in India. The cases can further decrease
if social distancing is followed in conjunction with restricted movement.