Accounting for Imported Cases in Estimating the Time-Varying Reproductive Number of Coronavirus Disease 2019 in Hong Kong
Tim K. Tsang, Peng Wu, Eric H. Y. Lau, Benjamin J. Cowling
Abstract
Estimating the time-varying reproductive number, Rt, is critical for monitoring transmissibility of an infectious disease. The impact of imported cases on the estimation is rarely explored. We developed a model to estimate separately the Rt for local cases and imported cases, accounting for imperfect contact tracing of cases. We applied this framework to data on coronavirus disease 2019 outbreaks in Hong Kong. The estimated Rt for local cases rose above 1 in late March 2020, which was undetected by other commonly used methods. When imported cases account for a considerable proportion of all cases, their impact on estimating Rt is critical.
Topics & Concepts
OutbreakCoronavirus disease 2019 (COVID-19)EstimationDiseaseSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2)Transmissibility (structural dynamics)Contact tracingCoronavirus2019-20 coronavirus outbreakPandemicInfectious disease (medical specialty)MedicineDemographyGeographyVirologyInternal medicineEconomicsSociologyQuantum mechanicsVibrationVibration isolationManagementPhysicsCOVID-19 epidemiological studiesData-Driven Disease SurveillanceVaccine Coverage and Hesitancy