Global Emergence and Spread of the SARS-CoV-2 Omicron Variant for Evaluation of Outbreak Detection

This dataset contains the estimated timing of the emergence and spread of the Omicron variant among 121 countries from September 1, 2021, to January 1, 2021, based on the frequency of Omicron genome samples collected. The Omicron variant genome sequences were collected worldwide and submitted to the Global Initiative on Sharing All Influenza Data (GISAID, https://gisaid.org/) by data contributors of GISAID. The metadata of these genome samples was obtained from gisaid.org and used to calculate the frequency of Omicron samples collected in the selected countries. A Bayesian online change point detection algorithm (BOCP) was then used to identify significant increases in this frequency in each country. The detected change points were validated by comparing them with temporal trends in COVID-19 incidence and the earliest introduction of Omicron to each country as estimated by phylogenetic analysis. This dataset can be used to evaluate the accuracy and timeliness of algorithms for early outbreak detection, supporting research and pandemic preparedness.