Background
To date most traceability apps to assist with covid 19 tracing have been based on geolocation. In reality the key information required for anyone diagnosed, is who they were in contact with over the last 21 days and how long they were in contact with that person, and also how close they were to that person.

Functionality

On each phone there is a database which holds

1) IMEI number of other local phones

2) Time stamp first contact of IMEI number

3) Time stamp for last contact of IMEI number

The data is gathered from other mobile phones running the app via Bluetooth

The app polls once a minute for local phone IMEI number.

Utilising Bluetooth results are primarily only local contact results being delivered

The data is held on the device for 21 days (or longer dependent on clinical guidance)

When traceability is required, network operators can access the app and convert the stored IMEI number to contact information to trace people.

The time stamps info will identify people who have been in contact for a very short period, such as passing them on a walk, which is potentially not critical as against a longer period which will therefore maximise tracing resources.

For this to be effective the majority of the population will have to download the app to their phone

For additional security the database on the phone can be encrypted

To be successful this needs to be a government national implementation rather than being some corporate venture which potentially will be mistrusted

Phone schematic

Phone P1 has stored IMEI of P4,P6,P3

Phone P2 has stored IMEI of P10,P8

Phone P3 has stored IMEI of P1, P9

Phone P4 has stored IMEI of P1, P8

Phone P5 has stored IMEI of none of them

Phone P6 has stored IMEI of P7,P1

Phone P7 has stored IMEI of P8,P6

Phone P8 has stored IMEI of P4,P7

Phone P9 has stored IMEI of P3,P11

Phone P10 has stored IMEI P11, P2

Phone P11 has stored IMEI of P10,P9

Along with time stamps

* To be used worldwide
* To be installed before any COVID-19 symptoms develop
* To be available in most world languages
* To clearly describe how it operates
* To transparently explain what user data is shared and how privacy is achieved
* To dissuade users from falsely reporting that they tested positive
* (Potentially) to allow users to report that they have symptoms but were unable to get tested
* To have a simple bullet point description (also available in most world languages)
* Could be rolled out through the World Health Organization (probably the best chance of getting it adopted and translated globally)
* Would need to be made available on Google Play and Apple App Store
* Would be free and ideally open source

Oxford University page does not allow comments, else I would have posted this comment there.

Hi Carole, NHS Digital has said the notes can be accessed via NHS 111 (https://111.nhs.uk/isolation-note/) or NHS.UK, as well as via the NHS app.

I like it. I have family in other countries.

Can’t connect day 2

Is this legit. Can’t connect day 2. Feel I’ve been had.

Or any of the other apps …. “not invented here”

An app is probably good but it is part of the solution. I can self isolate by using nhs111 online, I can be told to self isolate by telephone triage by GP, 111, etc. I can be tested by a lab system.

For the app to be effective, wouldn’t it need access to this data, probably as few sources as possible? Ideally these systems collect and make a available similar templates with coded entries (snomed, icd9 and/or read?). The key sources can be populated other systems. (Key sources include gp systems).
All of these have ready made solutions. Some things we dont know, what do the tests look like, what information do you want shared, what codes, etc.

Can we stop the ‘social’ distancing on tech and process?