Epidemic Network Percolation
SIR spreading on networks with contact tracing interventions
Network & Epidemic
N nodes:
120
Avg degree ⟨k⟩:
4.0
Transmission p:
0.30
Recovery γ:
0.15
Contact trace η:
0.0
Network type:
Erdős–Rényi
Scale-free (BA)
Small-world (WS)
Restart Epidemic
R₀ = p·⟨k⟩/γ:
—
Susceptible:
—
Infected:
—
Recovered:
—
Final size:
—
R_eff = R₀·(S/N)·(1-η·trace)
Epidemic spreading on networks exhibits percolation: above threshold
R₀>1
, a giant component of infected nodes spans the network.
Contact tracing quarantines fraction
η
of traced contacts, effectively reducing R_eff. Scale-free networks have
p_c→0
(no threshold!).