How infectious disease surveillance works

Framework and principles

In Luxembourg, infectious disease surveillance is a core pubic health responsibility of the Health Inspection Division within the Directorate of Health. It operates under a national legal framework that sets out which diseases must be reported, who must report them, and how the information is shared.

The law of 1 August 2018 on mandatory disease notification in the context of pubic health protection, together with a Grand-Ducal regulation from 2019 and the Health Code, defines the list of diseases and pathogens that must be reported to the health authorities, along with reporting deadlines and the minimum data required. This list is regularly updated to reflect changing health risks and European requirements. It currently includes 74 diseases or pathogens, which must be reported by laboratories and, for some of them, by doctors.

The system has two main aims: to detect health threats as early as possible and to enable a fast, coordinated response, while fully respecting data protection rules and national and international reporting obligations.

A historically fragmented system facing growing demands

As in many countries, epidemiological surveillance in Luxembourg has developed gradually, using tools and reporting pathways created at different times and for different purposes. It still relies in part on a mix of parallel channels: online reporting through dedicated platforms, paper or PDF forms, email exchanges, Excel files, and separate sector-specific databases depending on the actors involved (doctors, laboratories, hospitals, health authorities).

While these arrangements support compliance with legal reporting obligations, their coexistence makes the flow of information less smooth. Data can arrive at different speeds, be hard to link or standardize, and place a heavy administrative burden on health professionals. At a time when expectations for speed, data quality, and interoperability keep rising, these limits make it harder to obtain a clear, timely picture of the health situation.

The COVID-19 pandemic brought these challenges into sharp focus. It also accelerated the development of more integrated digital solutions, capable of supporting large-scale surveillance and real-time crisis management.

Multiple sources, close to the field

Doctors report notifiable diseases and feed the system through different channels: electronic notifications, online investigations, or, when necessary, more traditional reporting routes. This clinical information is a key link for interpreting laboratory data and triggering investigations.

Hospital and private laboratories send diagnostic results (positive tests or, for some diseases, both positive and negative tests) in a structured format. These biological data form the objective basis of surveillance and make it possible to track the circulation of infectious agents.

Patients also play an active role by providing information through digital questionnaires, particularly for certain notifiable diseases or within specific schemes such as tick-bite surveillance. These data complement clinical and laboratory information by adding essential contextual elements.

Integrating hospitals and emergency departments

In 2024, Luxembourg introduced surveillance of severe acute respiratory infections (SARI) under the RASSUR (Recueil Automatisé – Système de SURveillance syndromique dans les services d’urgence) project, in order to strengthen monitoring of severe respiratory infections in hospitals. The developments from RASSUR have since been taken up within WP4 of the PHRESH project. A major contribution of PHRESH, clearly shown in the infographic, is the integration of hospital emergency departments as a full data source in their own right.

Information on admissions, symptoms, and diagnoses is transmitted in anonymized form. It supports syndromic surveillance alongside traditional reporting and provides greater capacity to detect unusual signals quickly, especially during activity peaks or emerging situations.

SORMAS as the central hub

All these flows (clinical data, laboratory results, and questionnaire data) come together in SORMAS, which acts as the central system for managing cases, contacts, and events.

SORMAS makes it possible to:

• bring together information that was previously scattered;
• standardize data formats;
• make analysis easier for surveillance teams.

Depending on how the data are used, some information is pseudonymized or anonymized before being analyzed for epidemiological purposes or shared with other systems.

Linking to Europe and One Health

The infographic also shows that the system is designed to be interoperable at European level, with anonymized data transmitted to the ECDC in line with European surveillance frameworks.

In addition, PHRESH is introducing a national One Health exchange platform that links actors in human, animal, food, and environmental health. This platform allows signals, events, and analyses to be shared between institutions (ALVA, LNS, LIH, LIST, AGE, ANF), enriching surveillance with complementary data from the environment and animal health.

Analysis, visualization, and alerts

The data brought together in SORMAS then feed into:

• an anonymized data warehouse at the Directorate of Health;
• dashboards tailored to different audiences (health professionals, health authorities, and the general pubic);
• alert mechanisms designed to flag unusual trends or situations requiring special attention.

These tools give epidemiologists, analysts, and pubic health experts a clear and up-to-date picture of the health situation.

An end-to-end approach

Taken as a whole, the diagram shows the shift toward more integrated, more responsive, and better coordinated surveillance, in which:

• data move from the field to analysis;
• analysis feeds decision-making and communication;
• exchanges between sectors strengthen the overall understanding of health risks.

This end-to-end logic is what PHRESH aims to build and sustain.