The Community Acute Respiratory Infection surveillance programme: an evaluation of a newly established surveillance programme in Scotland

The Community Acute Respiratory Infection (CARI) surveillance programme, established by Public Health Scotland (PHS) in November 2021, aims to monitor respiratory infections in communities, replacing prior schemes to ensure early detection of outbreaks and inform public health interventions. Positioned as a cornerstone of PHS's national infectious respiratory diseases plan, CARI is pivotal for safeguarding public health. This study presents key findings from the 2022/23 CARI season and evaluates the programme's performance during this period. CARI uses a network of sentinel general practitioner (GP) practices across Scotland to monitor patients with acute respiratory infection symptoms, employing multiplex polymerase chain reaction testing for 10 common pathogens. Results are linked to enhanced surveillance data, providing insights into infection trends during the season. The evaluation comprised an online GP survey and a quantitative assessment of programme performance. In the 2022/23 season, 180 GP practices participated in CARI, testing 15,823 samples. Swab positivity peaked in December 2022, driven by a large spike in influenza A activity. The evaluation showed that CARI is highly useful, with positive feedback on simplicity, flexibility, and acceptability. Representativeness varied across health boards and age groups. Despite occasional laboratory processing delays, data quality remained good, with timely reporting and stable participation. CARI reflected patterns in infections observed in secondary care in Scotland and Europe, providing valuable insights into disease patterns and impact. It also provided timely intelligence to key decision-makers, enabling prompt public health response. Changes for the 2023/24 season aim to further optimize the programme.