Evaluating the impact of test-trace-isolate for COVID-19 management and alternative strategies
Fig 2
Example of the Test-Trace-Isolate strategy.
Once the primary case A develops symptoms, the sample is collected with delay. After the sample collection, A’s contacts on the temporal contact layer are disconnected until the test result is returned. If the test result is positive (which is the case in this figure), A is isolated, thus the contacts on both layers are disconnected over 14 days. If the test result is negative (i.e., false negative), the disconnected links recover. A infects individual B through a contact on the temporal contact layer (before A’s sample collection) and infects individual C through a contact on the static contact layer before the test result is returned. Individuals B and C are traced and tested immediately after the infection of A is confirmed. The links of B and C on the temporal layer are disconnected until the test results are returned. If the infection of the traced individuals (B in this figure) is confirmed, further contact trace is triggered. If the infection of the traced individuals (C in this figure) is not confirmed (i.e., false negative), the disconnected links recover.