Estimation of COVID-19 under-ascertainment in Kano, Nigeria during the early phase of the epidemics

Abstract Estimating the number of cases under-ascertained by inconsistencies is an essential concept in epidemiology. The aim of this study is to estimate the number of COVID-19 under- ascertained ( η ), and the basic reproduction number ( R 0 ) in Kano, Nigeria during the early epidemic period. We adopt a simple exponential growth model to capture the COVID-19 epidemic curve in Kano. Our findings indicate that the early epidemic growth mimics an exponential growth pattern. We find that the number of COVID-19 cases under-ascertained likely occurred during the fourth week of April 2020, and should be considered for future epidemiological investigations and mitigation plan.