Subharmonic bifurcation in an S-I-R epidemic model
- PMID: 6886569
- DOI: 10.1007/BF00305757
Subharmonic bifurcation in an S-I-R epidemic model
Abstract
An S leads to I leads to R epidemic model with annual oscillation in the contact rate is analyzed for the existence of subharmonic solutions of period two years. We prove that a stable period two solution bifurcates from a period one solution as the amplitude of oscillation in the contact rate exceeds a threshold value. This makes rigorous earlier formal arguments of Z. Grossman, I. Gumowski, and K. Dietz [4].