  The outbreak of corona virus disease 2019 (COVID-19), caused by the virus
severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has already
created emergency situations in almost every country of the world. The disease
spreads all over the world within a very short period of time after its first
identification in Wuhan, China in December, 2019. In India, the outbreaks
starts on $2^{nd}$ March, 2020 and after that the cases are increasing
exponentially. Very high population density, the unavailability of specific
medicines or vaccines, insufficient evidences regarding the transmission
mechanism of the disease also make it difficult to fight against the disease
properly in India. Mathematical models have been used to predict the disease
dynamics and also to assess the efficiency of the intervention strategies in
reducing the disease burden. In this work, we propose a mathematical model to
describe the disease transmission mechanism between the individuals. We
consider the initial phase of the outbreak situation in India and our proposed
model is fitted to the daily cumulative new reported cases during the period
$2^{nd}$ March, 2020 to $24^{th}$ March, 2020. We estimate the basic
reproduction number $(R_0)$, effective reproduction number (R(t)) and epidemic
doubling time from the incidence data for the above-mentioned period. We
further assess the effect of preventive measures such as spread of awareness,
lock-down, proper hand sanitization, etc. in reducing the new cases. Two
intervention scenarios are considered depending on the variability of the
intervention strength over the period of implementation. Our study suggests
that higher intervention effort is required to control the disease outbreak
within a shorter period of time in India. Moreover, our analysis reveals that
the strength of the intervention should be strengthened over the time to
eradicate the disease effectively.
