Surveillance of hospital admissions with respiratory tract infections in Norway - possibilities and hurdles

This document outlines the necessity for developing a system for surveillance of hospital admissions 
with laboratory-confirmed respiratory infections in Norway. Its basis is drawn from the learnings and
knowledge of the system (Beredt C19) that we established during the COVID-19 (Coronavirus disease 
2019) pandemic and seeks to further describe the building blocks for a new system to be operated in 
peacetime.

During the COVID-19 pandemic, using linked data sources for real-time monitoring of respiratory 
infections played a vital role in producing timely knowledge to support decision making. Participating
in the Joint Action - Union and National Capacity Building 4 IntegraTED Surveillance 
(UNITED4Surveillance) has given the Norwegian Institute of Public Health (NIPH), alongside the 
Norwegian Directorate of Health, the opportunity to apply the insights gained from the pandemic.

The NIPH pilot focuses on planning and designing a concept for a surveillance system that utilizes 
existing data sources to provide routine surveillance data for respiratory infections. The system aims 
to be capable of scaling up in case of a crisis while ensuring legal and privacy aspects, addressing 
infrastructure deficits, and identifying necessary data sources.

Norwegian data sources typically cover the entire population and can be linked through unique 
personal identifiers. Those relevant for the surveillance system are identified and described in the 
current report. By linking data from the hospital database (NPR), the laboratory database (MSIS) and 
the population registry (FREG) the number of laboratory-confirmed hospital admissions, including 
severity indicators and deaths can be supplied. With the addition of data on vaccinations (SYSVAK), 
primary health care utilization (KPR) and medications (NorPD), the system can give important 
information about vaccination status and medical risk factors, while the remaining four identified 
registries (AA-register, SSB, NiPAR and CoDR) can give supplementary information e.g., in studies of 
vaccine effectiveness.

Since January 1st, 2024, the NIPH has been data controller for the main health registers in Norway, 
although the operational data controller responsibility is delegated to the different units within NIPH. 
The legal framework concerning the processing of personal health data and coexistence between 
relevant laws are discussed. Based on NIPH’s interpretation of the Personal Health Data Filing System 
Act (“helseregisterloven”) §§ 19 – 19c, this is now considered the main legal basis to allow the 
continuation of a SARI (severe acute respiratory infection) surveillance system. Routine surveillance in 
peace time may be achieved by compiling health data from the health registries, producing
anonymous statistics to contribute to fulfilling the NIPH’s obligation for surveillance of communicable 
diseases.

Additionally, technical challenges related to data timeliness, security, protocols, and necessary 
resources are highlighted. It is important to build on the advantages that exist with current systems 
in place and look to re-use parts or entire infrastructure, components, and solutions for future 
development. In the case of this pilot, we have used the system of Beredt C19 as an illustration of 
how data sharing was operated within NIPH during the COVID-19 pandemic.

This pilot forms the basic framework for the development of such a surveillance system, and the 
recommendations will lay the groundwork for the implementation of the NORSURV Direct Grant (see 
“definitions”) to make improvements to the Norwegian surveillance systems for infectious diseases.