Setting up Surveillance of Severe Acute Respiratory infections in Intensive Care Units

Introduction

Establishing near-real time surveillance of Severe Acute Respiratory infections (SARI) is crucial for pandemic preparedness and for monitoring severity of influenza and other respiratory virus surges. ICU admissions represent the severest hospitalisations whose burden on ICU can easily overwhelm ICU capacity in outbreaks. Therefore the Dutch National Intensive Care Evaluation (NICE) registry was used to set up surveillance for ICU-SARI admissions.

Methods

The Dutch National Institute of Public health and the Environment (RIVM) and NICE collaborated to set up automated data extraction from hospital electronic records with no registration burden for hospital staff as a basis for weekly reports on ICU-SARI.

Results

NICE, in consultation with adult ICUs, transformed infrequent manual data transfer to automatic daily transfer via HL7 FHIR, followed by weekly aggregations sent to RIVM. An ICU-SARI admission was defined as a patient with a medical diagnosis upon ICU admission (Apache IV ICU admission diagnoses) of: Pneumonia: bacterial, fungal, parasitic, viral or other; Pulmonary sepsis; Influenza, Respiratory Syncytial Virus, or SARS-CoV2 infection. NICE data included in SARI surveillance: ICU-admissions, ICU-medical-admissions, ICU-SARI-admissions, ICU-SARI in-hospital death and time until death, individual diagnoses in the ICU-SARI definition, and comorbidities. These are aggregated by week and separately by age group, sex, province, and number of comorbidities. The first real time data publicly reported was in week 5 of 2025 on 8 ICUs. By week 14 of 2026, 37 of 70 ICUs were connected. On retrospective full-coverage data the average weekly incidence of SARI-ICU admissions was 0.79/100,000 adults (n = 112) or 5,802 yearly cases in non-pandemic years since 2016.

Discussion

With roughly 50% of Dutch adult ICUs currently connected and an aim of full coverage in the next two years an important gap in surveillance of respiratory infections is being bridged.

Key messages

• We set up near-real time surveillance of Severe Acute Respiratory infections (SARI) which is crucial for pandemic preparedness and monitoring severity of influenza and other respiratory infections.

• With approximately 50% of Dutch adult ICUs currently connected and an aim of full coverage in the next two years an important gap in surveillance of respiratory infections is being bridged.