COVID-19 Case Management & Hotspot Notification Server

Note: This project is under active development and not ready for production use.

This project aims to specify and implement a server to be deployed by health authorities to manage COVID-19 cases and notify users of hotspots based on reported location trails.

Table of Contents

• Setup
• Glossary
• Model
• Roles And Permissions
• Database Schema
• API Docs
• Deployment
• Milestones

Glossary

• Staff: An employee of a health authority. See Roles and Permissions for how health authorities may configure their system to control who can perform which functions.
• Case: An individual believed to be infected with COVID-19. While unused at the moment, an infection_risk parameter allows space in the model for some percentage chance that an individual is infected, - perhaps based on their self-reported symptoms.
• Location Trail Point: A point in space and window in time where an infected individual was present. These may be sent by that individual's mobile device or entered by a staff member during a conversation with the infected individual.
• Hotspot: A region in space and window in time where infected individual(s) were present. Note that hotspots define an area, not just a point. See Hotspot Determination for more information about how health authorities might configure how these are found.

Model

Open Case -> Case Management -> Consent to Make Public -> Hotspot Determination -> Hotspot Notification -> Case Cleanup

Open Case

A case is opened with the user's consent by a health authority staff member or by a user who may access the route via an auth code sent to their device for that purpose.

Case Management

Points in the location trail are added and/or redacted with a view towards privacy/efficacy.

Consent to Make Public

Consent is received to make the nonredacted points in the location trail public, that is, used to determine hotspots.

Hotspot Determination

The nonredacted location trail points are used to find hotspots, regions where infected individual(s) were present for a prolonged period of time.

At its most basic, we're trying to find a circle of fixed radius on the globe, say 20m, and a block of time, say an hour, inside which location trail points are present and whose time ranges sum up to some length of time, say 50 minutes.

More complicated models might weigh infection risk, number of cases in the region, length of time in the region, whether the location is indoors, etc.

Hotspot Notification

The public is notified of hotspots. This might be a manual process where health authority staff see the new hotspots and follow up with associated cases, or might be sent to mobile users to match against their own location trails.

Cases Cleanup

Cases and their location trail points more than 21 days old are cleaned up periodically.

Roles and Permissions

Specific roles such as "admin" or "contact_tracer" aren't defined in this specification. Instead, roles and permissions may be set up by a database administrator to suit a particular health authority's needs. A basic setup with 2 user roles might look like this.

role	method_pattern	route_pattern
admin	*	*
contact_tracer	*	/v1/cases*
contact_tracer	POST	/v1/authcode/create

This would allow someone with the admin role to access all methods for all routes, while someone with the contact_tracer role can access all case related roles and can create auth codes. See API Docs for more information on methods & routes.

Database Schema

id, created_ts, and updated_ts are present for each model

roles

• role

permissions

• role_id
• method_pattern
• route_pattern

staff

• username
• password
• role_id
• contact_info

cases

• patient_record_info
• infection_risk
• created_by_staff_id
• consent_to_make_public_received
• consent_to_make_public_given_at
• consent_to_make_public_received_by_staff_id

location_trail_points

• case_id
• location
• start_ts
• end_ts
• redacted

hotspots (planned)

• epicenter_location
• radius
• start_ts
• end_ts
• made_public

Milestones

• Manual Case Management
  • Roles & Permissions
  • Case Creation
  • Redaction & Consent
  • Simple Algorithm for Hotspot Determination
  • Manual Hotspot Notification
  • Case Cleanup
  • Health Authority Metadata
• Mobile Connection
  • Auth Code Generation
  • Device Attestation
  • Automated Hotspot Notification
• Model Improvements
  • Configurable Algorithm for Hotspot Determination
  • Self Reporting
  • Infection Risk?

Parallel Work

• Development & Deployment
  • CI/CD Pipeline
  • Deployment Guide
• Privacy/Security
  • Threat Model re: Hotspot Notification
  • Server Audit
• Testing
  • Mess with datetimes
  • Mess with locations
  • Mess with doing things outside the API Docs