Networks portray a multitude of interactions through which:
- people meet,
- ideas are spread, and
- infectious diseases propagate within a society.
Identifying the most efficient “spreaders” in a network is an important step to
optimize the use of available resources and ensure the more efficient spread of information.
Here we show that:
1. in contrast to common belief, the most influential spreaders in a social network do not correspond to the best connected people or
2. to the most central people (high betweenness centrality).
3. the most efficient spreaders are those located within the core of the network,
as identified by the k-shell decomposition analysis
4. when multiple spreaders are considered simultaneously, the distance between them
becomes the crucial parameter that determines the extend of the spreading
5. in the case of infections, which do not confer immunity on recovered individuals,
the infection persists in the high k-shell layers of the network
under conditions, where hubs may not be able to preserve the infection
6. there is a plausible route for an optimal design of efficient dissemination strategies