Definition of cases
Sciensano definitions of cases and contacts are as follows:
A possible case of COVID-19 is a person in whom symptoms of acute lower or upper respiratory tract infection appear (or worsen in people with chronic respiratory symptoms). From April 1st, a new definition was added: a ‘radiologically probable case’ is an individual whose laboratory test for COVID-19 is negative but for whom the diagnosis of COVID-19 is nonetheless made on the basis of an evocative clinical presentation AND a compatible chest CT scan. On April 17th the High Council for Health published recommendations on the use of chest CT scans as diagnostic mean. In summary, despite its high sensitivity, chest CT scans should not be used as first line diagnostic tool, nor as a systematic screening tool, and should always be combined with PCR-testing. (French: https://covid-19.sciensano.be/sites/default/files/Covid19/Avis%20du%20CSS%20concernant%20l%e2%80%99utilisation%20du%20CT-scan.pdf; Dutch: https://covid-19.sciensano.be/sites/default/files/Covid19/Advies%20van%20de%20HGR%20betreffende%20het%20gebruik%20van%20CT-scans.pdf). From May 4th, the definition of ‘possible cases’ was also enlarged: A ‘possible case’ of COVID-19 is a person with at least one of the following major symptoms (with no apparent cause): cough; dyspnoea; chest pain; anosmia or dysgeusia without apparent cause; OR at least two of the following minor symptoms (with no apparent cause): fever; muscle aches; fatigue; rhinitis; sore throat; headache; anorexia; watery diarrhoea; acute confusion; sudden fall); OR an aggravation of chronic respiratory symptoms (COPD, asthma, chronic cough, etc.) with no apparent cause.
A confirmed case of COVID-19 is a person who has a laboratory-confirmed diagnosis of COVID-19;
A close contact is defined as a family (co-habitant) contact or equivalent, or a care contact in the context of aerosol-producing action. Close contacts are mandated to carefully monitor their health (self-monitoring) for a period of 14 days. In the event of an acute infection of the lower or upper respiratory tract, the person becomes a possible case and has to contact his/her GP by phone. A laboratory test is not necessary (unless he/she is a health care professional with a fever). The definition of a ‘close contact’ disappeared from April 1st and reappeared from July 29th, but defined as contact people can have outside their household for more than 15 minutes, without a distancing of 1.5m and without a facemask. From the beginning of May, in the context of the contact tracing strategy, a similar notion was also introduced, i.e. high-risk contacts.
A high-risk contact is defined as follows: a person who has cumulative contact of at least 15 minutes within a distance of less than 1.5 m ("face to face"); a person who was in the same room/closed environment for more than 15 minutes with a COVID-19 patient, where a distance of 1.5 m was not always respected (except when plexiglass divisions were used) and/or where objects were shared. This includes all classmates for children under 6 years and neighbours in a classroom with children under 7 years old; a person who has had direct physical contact with a COVID-19 patient; a person who has been in direct physical contact with excretions or body fluids of a COVID-19 patient, such as during kissing and mouth-to-mouth ventilation, or contact with vomit, bowel movements, mucus, etc.; a caregiver in contact with a COVID-19 patient during care or medical treatment or examination within a distance of 1.5m, without the use of personal protective equipment (according to protocol/activity); a person who has travelled with a COVID-19 patient for more than 15 minutes, in any means of transport, seated within two seats (in any direction) from the patient.
Contact tracing was started at the beginning of the epidemic, when there were only a few patients, but it was progressively abandoned given the outburst of infection.
Sciensano (the national institute for epidemiology) centralises the data about COVID-19 from the national reference lab, the hospitals, the residential care centres, the General Practitioners (GPs) and the network of sentinel GPs (https://www.sciensano.be/en/projects/network-general-practitioners) and hospitals for the monitoring of flu-like syndrome. (More information on https://www.sciensano.be/en/press-corner/covid-19-figures-sciensano-collects-verifies-and-publishes).
Hospitals must send a report to Sciensano each day before 11:00 a.m., with their number of hospitalised COVID-19-patients, deaths and discharges.
Residential institutions that accommodate people in at-risk groups (e.g. older people) must complete a report each day before 11:00 a.m., with the presence of COVID-19 cases in the facility (among residents and staff), even if there have been no new cases. The declarations must be encoded via a centralised and secure application and sent to Sciensano.
Beginning in April, a controversy arose in the media about the exact number of deaths in Belgian nursing homes, which could have been under-reported. The addition of numerous deaths in nursing homes suddenly increased Belgium's mortality figures in international comparisons. But it also appeared that the Belgian data encompassed both the deaths of patients or residents who were confirmed COVID-19 and those who were suspected of being infected, whereas other countries only registered the number of deaths of confirmed cases. Indeed, the results of the first tests performed in Belgian nursing homes for older people showed that up to half of the symptomatic residents had a negative COVID-19 test. The Risk Assessment Group was then urged to clarify and standardise the registration procedure.
Ambulatory cases had to be notified to the federated entities but this obligation was lifted on March 18th (except for residential institutions, where it remains more necessary than previously). Only deaths occurring outside the hospitals have to be notified.
Several online initiatives have been developed to help physicians monitor the health of their COVID-19 patients at home (see also section 2.2). The anonymised data are made available to researchers and competent authorities in order to monitor the security measures linked to the epidemic.
Regularly updated guidelines for health care professionals and for residential care can be found on the websites of Sciensano and on the websites of the Federated entities:
• Sciensano (2020). Coronavirus. Brussels: Sciensano (https://epidemio.wiv-isp.be/ID/Pages/default.aspx, Accessed April 2020) ;
• Flemish Agency for Care and Health (2020). Uitbraak coronavirus COVID-19. Brussels: Flemish Agency for Care and Health – Agentschap Zorg en Gezondheid (https://www.zorg-en-gezondheid.be/covid-19, Accessed April 2020);
• AVIQ (2020). Coronavirus 2019. Charleroi : Agency for a Quality Life-Agence pour une vie de Qualité (https://www.aviq.be/coronavirus.html, Accessed April 2020) ;
• Iriscare (2020). COVID-19. Brussels: Iriscare (http://www.iriscare.brussels/fr/professionnels/, Accessed April 2020);
• Ostbelgienlive (2020). Coronavirus: Fragen und Antworten. Eupen: Ostbelgienlive (http://www.ostbelgienlive.be/desktopdefault.aspx/tabid-6711/, Accessed April 2020).
Different strategies for tracing the contacts of all COVID-19 positive patients have been considered. A federal legal framework for a contact tracing application has been studied; the principle is that the technology has to be open source, only anonymised data will be used, and Bluetooth technology would be used rather than geolocation technologies. If different applications are to be used in the different regions, they should be compatible with each other and with the federal eHealth platform. On April 30th, the Belgian Data Protection Authority published some recommendations and conditions regarding such an application (French: https://www.autoriteprotectiondonnees.be/news/avis-de-l-APD-sur-arretes-royaux-relatifs-aux-applications-de-tracage-et-base-de-donnees-covid-19; Dutch: https://www.gegevensbeschermingsautoriteit.be/nieuws/adviezen-van-de-GBA-op-voorontwerpen-inzake-opsporingsapplicaties-en-covid-19-databanken )
The launch of the contact tracing application occurred on September 30st.
Meanwhile, the solution of ‘human’ tracing (by telephone) has been preferred to technological tracing, at least for the first stage. The principle is that Sciensano centralises the data from all test results (which has been the case since the beginning of the epidemic); these results are then dispatched to the health administrations of the federated entities who organise contact tracing at the local level (telephone calls to the patients in order to identify all their contacts).
The Inter-ministerial conference agreed that identical procedures should be followed in all federated entities and a working group was created in order to set up a common platform and tools (see section 5 on Governance). Two thousand people were recruited, with some of them already working in the administration, and others through public tenders launched by the federated entities. From May 4th, call centres have been set up. The contact tracking system has been gradually expanded to reach its maximum capacity in the following weeks.
On May 20th the Inter-ministerial conference also agreed on a framework for enhanced surveillance of the epidemic in complement of the tracing (i.e. a barometer of the epidemic). The aim is to detect any local resurgence of the virus, or a possible second wave, as soon as possible and to take targeted measures. It will operate according to a step-by-step principle, i.e. the worse the situation gets, the more restrictive measures need to be taken. This barometer will be based mainly, but not exclusively, on the evolution of the number of hospitalisations. The development of this second line of defence will be further refined so that it can be implemented in the short term by the infectious disease surveillance services at national, regional and provincial levels.
New restrictions: Monitoring and surveillance
Tracing has been reinforced since July 29th (July 25th in the catering industry, i.e. for restaurants, cafes and bars) and contact information is now requested in specific situations where there is higher risk of transmission (e.g. in the catering industry, in wellness and sport centres, etc).
It is also crucial that test results are made available to the surveillance agencies very quickly. Rapid transfer of test results is therefore one of the quality requirements that laboratories have had to meet since July 20th.
Vaccination surveillance is described in section 3.1.