Inefficient epidemic spreading in scale-free networks
Carlo Piccardi1, Renato Casagrandi
1Dipartimento di Elettronica e Informazione, Politecnico di Milano, Piazza Leonardo da Vinci, 32, I-20133 Milano, Italy. carlo.piccardi@polimi.it
Summary
Heterogeneous networks efficiently spread simple epidemics but struggle with complex diseases. Diseases with nonlinear infection forces may collapse on scale-free networks, unlike in homogeneous ones.
Area of Science:
- Epidemiology
- Network Science
- Mathematical Biology
Background:
- Heterogeneous networks, common in real-world systems, facilitate rapid spread of simple epidemic models.
- Complex epidemiological processes, particularly those with nonlinear dynamics, may behave differently on these networks.
Purpose of the Study:
- To investigate the impact of network heterogeneity on diseases with nonlinear force of infection.
- To compare disease persistence and prevalence in scale-free versus homogeneous networks.
Main Methods:
- Mathematical modeling of disease spread.
- Analysis of nonlinear epidemiological dynamics.
- Comparison of network structures (scale-free vs. homogeneous) with identical average degrees.
Main Results:
- Scale-free networks can fail to sustain diseases with nonlinear infection dynamics.
- These diseases may exhibit abrupt prevalence collapse on heterogeneous networks.
- In contrast, homogeneous networks can maintain high endemic disease levels under similar conditions.
Conclusions:
- Network heterogeneity, while beneficial for simple epidemics, can be detrimental for diseases with nonlinear transmission.
- The structure of the network significantly influences the persistence and dynamics of complex epidemics.
- Findings highlight the importance of network topology in understanding disease dynamics and control strategies.
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