Otoi-NARIMA Model for forecast seasonality of COVID-19 waves: Case of Kenya

Abstract

Introduction/ Background: Kenya's three waves caught authorities responsible for disease surveillance of the pandemic with surprise, resulting in loss of life and livelihoods. There was need for accurate modelling to inform surveillance, planning, budgeting, enhanced response, and accelerated recovery to save lives. The length of duration, seasonality, and periodicity are desired. Methods: 392 daily cases data from March 13, 2020 to April 9, 2021 was used after relevant statistical tests. Normalized series and ordered moving averages are superimposed, tested for stationarity and cointegration to establish order of integration I(d) and cointegration rank. The series are used to derive OTOI-NARIMA model. The model is tested for auto-correlation (ACF/PACF) and validity (Ljung-Box test). The restricted model is used to forecasts and visualised to describe trajectory of Kenya's 3rd and 4th Waves. Results: OTOI-NARIMA is superior and accurately predicted both the 3rd and 4th Kenyan waves and peak intensities. It precisely established seasonality and periodicity of waves. Model projections were used to inform covid-19 resurgence preparedness in LREB-Kenya before peak intensities on June 26 and August 11, 2021. During the assessment, health systems strengthening and covid resources coordination were recommended in LREB. Based on the recommendations, COVID-Dx platform by PharmAccess Foundation is being used for effective and efficient covid-19 services coordination. In preparation for predicted 5th and 6th waves, between November, 2021 to June, 2022, COVID-Dx digitization is used to inform healthcare strengthening. Impact: Optimal use of fragile health infrastructure in LREB as a result of healthcare systems strengthening recommended after assessment of preparedness based on model predictions. Relatively, more lives have been saved and accelerated socioeconomic recovery and resilience of vulnerable communities. Conclusion: The OTOI-NARIMA model has been used in Kenya as a forewarning tool to inform preparedness, health systems strengthening, and public sensitization on vaccination ahead of predicted waves to safeguard lives and protect livelihoods.