Analysis and Forecast of Third Wave of COVID-19 Outbreak in Sri Lanka

A.M.P. Chandrasiri

Abstract: The coronavirus disease (COVID-19) is a respiratory viral disease first reported in Wuhan city in China on December 2019 and turned pandemic worldwide. The World Health Organization declared the COVID-19 outbreak as a pandemic on 11th February 2020. The first case of COVID-19 was reported in Sri Lanka on 27th January 2020, a Chinese female visiting the country. The first local patient was reported on 11thMarch 2020 thus bringing about unprecedented changes in the daily life in the country. However, Sri Lanka successfully managed to control the spread of the first and second waves of the virus and kept the number of patients and deaths at a minimum. Now, Sri Lanka struggles to respond effectively to COVID-19 third wave. A simple model for predicting COVID-19epidemic is presented in this study. The prediction model is presented based on the classic Susceptible-Infectious-Recovered (SIR) model, which has been widely used to describe the epidemic time evolution of infectious diseases. The main purpose of this research is to estimate the parameters of SIR model and to predict the peak of the third wave of the COVID-19 pandemic in Sri Lanka using the data from 15th April 2021 to 25th June 2021. Data was obtained from daily situation reports of the Epidemiology Unit, Sri Lanka. The values of the rate of transmission and rate of removal are at 0.0966 and 0.07143, respectively. The peak of pandemic will be reached after approximately 142 days from its emergence in Sri Lanka. The percentage of infected persons at the peak of the third wave was estimated at 3.95% of the total population. The basic reproduction number was estimated at 1.3529. These results may be helpful to Sri Lankan authorities to adapt their strategies and may be taken into consideration in the future phase of discontentment. Further, it seems that this simple model is still reliable enough to describe the dynamics of the COVID-19 epidemic, not only qualitatively but also quantitatively with a high degree of correlation between actual data and prediction results.

Keywords: COVID-19, Pandemic, Parameters, Sri Lanka