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Digital contact tracing and network theory to stop the spread of COVID-19 using big-data on human mobility geolocalization

Fig 4

Evolution of GCC and k-cores over the quarantine.

Disease transmission networks in the state of Ceará over time before and after the lockdown on March 19, 2020. (A) Transmission network on March 19 (pre-lockdown). A hairball highly-connected network is observed. The disconnected components of the 7-core ( in this network) are colored. These components are well connected into the hairball network as expected since mobility and connectivity is high. (B) The pre-quarantine hairball in (A) has been untangled and the k-cores have emerged 8 days into the lockdown on March 27. Here, we color the nodes according to layers of the transmission network starting at COVID-19 patient (black nodes). Size of nodes is according degree. (C) Network on April 28 including the components of the 5-core in different colors ( for this network). Visible is the high betweenness centrality node representing the weak-link of this k-core. (D) We plot the location of the contacts in the map of Fortaleza constituting the components of the 5-core of the April 28 in (C). The size of the circles in the map corresponds to the number of contacts inside each location. The colors correspond to the clusters of the 5-core in (C). The 5-core sustaining transmission is composed of clusters of contacts localized in hospitals, large warehouses and business buildings. Hospital 3, one of the largest in Fortaleza, constitutes the maximal of the pandemic. The underlying map comes from the Folium library of Python: https://github.com/python-visualization/folium which relies on the OpenStreetMap project [29].

doi: https://doi.org/10.1371/journal.pcbi.1009865.g004