Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, how the Government will estimate (a) the level of prevalence of and (b) rates of infection and immunity to covid-19 if symptomatic patients are not tested.

The levels of prevalence and rates of infection are calculated based on laboratory confirmed cases. Public Health England (PHE) conducts surveillance of COVID-19 infection using a variety of data sources.

These include surveillance of influenza-like illness presenting to primary care, surveillance of outbreaks in schools, care homes and other community settings. PHE and the National Health Service have also established a surveillance system that reports daily on COVID-19 infections in persons requiring hospital and intensive care admissions.

Plans are in place for serological surveillance to collect data on the prevalence of infection as the outbreak progresses. This will involve the testing of samples from different sources to inform the epidemiological characterisation of COVID-19 immunity in the population.