The Coronalert app in the corporate context: breaking the contagion chain. Takeaways from the Beltug X-change: 27 October 2020

Companies have a lot of questions about contract tracing in a corporate environment. The launch of the national Coronalert app (the official Belgian contact tracing app) hopefully provides some answers, so in this session, we wanted to enable a discussion on its use in a working context.


Overall, companies’ main concern is how to keep the business operating most effectively whilst protecting the health and safety of employees. Beltug has already published a Paper to provide initial insights, and early on in the crisis, provided some information on contact tracing and social distancing tools.


To start off our dive into the Coronalert app, Frank Robben, CEO eHealth-platform & KSZ/BCSS provided insight into the purpose and various forms of contact tracing, and Coronalert’s role, at our Beltug X-change on 27 October 2020.


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Incubation versus contagiousness


Frank started off by explaining the difference between the incubation period and the contagiousness of Covid-19. The incubation period is the time it takes for a person to show symptoms, while the contagiousness is the potential for a carrier to transmit the disease. For Covid-19, contagiousness precedes the completion of the incubation period, meaning infected people can be contagious before they show symptoms. Hence, it is important to swiftly trace high-risk contacts of people that have tested positive to break the contagion chain.


The pillars of contact tracing


Contact tracing in Belgium is built on four pillars: doctors, contact centres, companies and meeting places, and the Coronalert app. Physicians are usually the general practitioners; people generally visit their doctor when they feel ill. The contact centres call infected persons to get an overview of their recent contacts. Companies and 'meeting places' include schools, restaurants and retirement places. For these, the association of health & safety officers has drawn up guidelines (in Dutch or French). Finally, the Coronalert app targets ‘blind’ contacts: people you have crossed paths with in the past 14 days, but who are otherwise unknown to you.


The role of centralised contact centres

The contact centres are centralised by Sciensano. If you have had a high-risk contact, you are provided with a test code for a Covid test. Companies will be contacted either through their company doctor or external prevention doctor, who will then assess the risk level of the contact, and advise accordingly. A high-risk contact means testing and quarantine. A low-risk contact means respecting social distancing and monitoring symptoms. Quarantine due to high-risk contact does not imply that you are unable to work remotely, when this is possible. If it is not possible, the options are sick leave (if you are actually ill) or temporary unemployment.


How Coronalert works: the red screen

Frank then took us through some more detail on the Coronalert app. When operational, the app broadcasts random codes (called ‘gibberish’) over Bluetooth to neighbouring devices. The app on the neighbouring devices then stores this gibberish if certain criteria are met. But it is not stored centrally, only in-app.


If you have had a high-risk contact, the app screen will turn red and provide you with a rough indication of when this contact would have taken place. You and your physician can then assess whether there was indeed a high-risk contact or only a low-risk contact.


Keep in mind that the app has no information on e.g. face masks, physical barriers (screens or walls) or any other precautionary measures. This means the app isn’t needed in circumstances where safety is guaranteed. If your office is adjacent to the street, and you are the only person there, the app will be unaware that there is a wall between you and passers-by outside. So you may prefer to turn it off.


If your app turns red, it can generate a test code for taking a Covid-test. If the test is positive, this code is also used to upload the codes the app has been broadcasting over the past days. Only the codes are uploaded onto the server, there is no identification attached to it.


Automatic deletion of codes

At regular intervals, Coronalert connects to the central server to check whether any of the codes it received has been flagged as a high-risk contact. Codes only remain in the central database for 14 days and are deleted automatically. So, if the virus stops circulating, the database will clear itself. If you have tested positive and your codes are uploaded to the central database, the app will cease to be operational and you will have to reinstall it. This was seen as the most effective way to prevent app functionality being compromised by a previous positive status.


Coronalert in Europe

In the short term, Coronalert will also be linked to the European gateway, making it usable in other EU countries. The only user intervention required is to indicate which countries you have visited when uploading your codes to the high-risk contact database.


Here are a few references with additional information:






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