3. Scotland's COVID-19 surveillance system
Effective surveillance of infectious disease is an important element of the public health system in Scotland. It involves gathering and interpreting data to understand where infection is occurring, and the effect it is having on people's health. In turn, it allows us to monitor and assess how well the steps that are taken to limit infections, are working. This information is used to quickly detect outbreaks and help make decisions about how to respond and control the spread.
There are existing disease surveillance systems in Scotland. Many of these use routine data, collected as part of people's normal everyday use of health care to help track what is happening to us. This means that Scotland already has excellent routine data sources, which are now also being used to tell us about COVID-19 in Scotland.
In addition to routine disease surveillance, enhanced health surveillance provides a more detailed picture by seeking out additional information on infections and the effects of infection. Both routine and enhanced surveillance systems have been expanded to meet the unprecedented challenge of COVID-19 response and work continues to strengthen them.
Building a full understanding of COVID-19 requires more detail than tracking numbers of positive cases alone. It is also important to know what sort of symptoms people are experiencing, how unwell people become, and who is most likely to become more unwell. As the response to the pandemic has developed, different groups of people have been able to access testing and by linking and comparing results to other data sources we are establishing a reliable picture of the number and spread of infections.
We are committed to go further to develop a more detailed picture of the levels of COVID-19 across Scotland. Work is in hand to collect information on symptoms and background health information from a sample of people who are being cared for in the community for illnesses that could be COVID-19. This is being further informed by the information that is being gathered through testing results and it will help us to understand more about the virus.
The COVID-19 surveillance system has a number of strands that informs us about the full range of illness severity, and provides tracking over time and for key groups of the population. The knowledge of local areas and situations, provided by NHS Board Health Protection Teams, is a crucial element of interpretation. Weighing up the importance of a change in one measurement and responding with proportionate interventions requires public health expertise. This, matched with the use of other data sources, supports our decision-making.
Key Data Sources
NHS24 Call Data (syndromic surveillance) tracking calls to NHS24 for symptoms that could be COVID-19 provides an early indication of any changes over time and in particular places.
Hospital and Nosocomial Data gathering data about those who have COVID-19, including those admitted to hospital, informs us about those with more severe illness, their care needs and outcomes.
Primary Care Data the primary care programme allows assessment of how many people who are unwell with symptoms that could be COVID-19 actually have the infection.
Antibody Testing a range of surveillance approaches use antibody testing to help establish how many people have had COVID-19 infection.
Understanding how the virus changes (whole genome sequencing) identifying particular strains of the virus helps pick up changes in strains circulating and supports investigation of clusters of cases.
Source: Scottish Government 2020
Through Test and Protect, the timely identification and isolation of contacts will allow us to break the chains of transmission. Combined with effective and reliable surveillance that provides information about clusters of cases, it will help us develop an early warning system that will inform our response and help us to contain any outbreaks that occur.
Test and Protect reduces the levels of community infection but to do this effectively, it is important that there is both an understanding of COVID-19 symptoms, the requirement to self-isolate when symptoms appear and the need to take appropriate action to quickly seek a test.
When notification of a positive test result is received, contact tracing services are quickly deployed. Those who may have been exposed because they are close contacts are identified and asked to isolate to prevent further transmission.
Maintenance of robust, representative and independent public health intelligence systems will be a core element of managing COVID-19 in Scotland. Public Health and research expertise in analysing and interpreting data is critical and the Scottish COVID-19 Data and Intelligence Network, described further in Section 4, will play a significant role in this as we move forward.