COVID-19 cluster surveillance using exposure data collected from routine contact tracing: The genomic validation of a novel informatics-based approach to outbreak detection in England
Fig 1
Periods of data collection for enhanced contact tracing.
The backwards period of contact tracing was that likely to reflect probable exposure for the case (3–7 day period before symptom onset or date of the positive test). Data was collected on events and activities at workplace, education, household and other settings (such as hospitality and leisure).