Respi-Radar, a tool to monitor respiratory infections in Belgium during the winter season 2023-2024

Following the experience gathered during the COVID-19 crisis, the Respi-Radar was developed by the Belgian Risk Assessment Group (RAG) in the summer of 2023, with the aim of assessing the epidemiological situation of respiratory infections and informing public health preparedness and response in Belgium. The Respi-Radar consisted of four levels (green, yellow, orange and red) which indicated the extent of viral circulation and/or pressure on the healthcare system. Depending on the level, specific measures would apply to reverse the trend. The Respi-Radar used six indicators, from the Influenza-Like Illness and Severe Acute Respiratory Infection sentinel surveillances in nursing homes, primary and secondary care, as well as from the wastewater surveillance. Additional information, such as data from the national reference laboratories, also contributed to assessing the situation. Based on the Respi-Radar tool, the RAG regularly evaluated the epidemiological situation of respiratory infections between September 2023 and March 2024. The Respi-Radar tool appeared useful for following trends and effectively communicating on the epidemiological situation of respiratory infections. Applying specific measures depending on a level was less straightforward. The experience gained using the Respi-Radar tool was key to determine the best approach to assess and manage the epidemiological situation for future respiratory seasons.