Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, what steps his Department has taken to assess the frequency of different modes of transmission of covid-19 using (a) NHS Test and Trace cases and (b) other available data on common methods of covid-19 transmission.

Public Health England works closely with the Scientific Advisory Group for Emergencies (SAGE) to look at different modes of transmission of COVID-19.

There are a range of approaches to understanding and assessing transmission including outbreak investigations, case control studies, surveillance studies, intervention studies, laboratory studies and modelling, which all have strengths and biases. Different approaches need to be applied and analysed together to identify factors that influence transmission. The majority of data shows correlations and associations, but rarely proves causation and no single data source provides complete evidence for how and where transmission takes place.