Abstract.
It is shown that an SIS epidemic model with a non-constant contact rate may have multiple stable equilibria, a backward bifurcation and hysteresis. The consequences for disease control are discussed. The model is based on a Volterra integral equation and allows for a distributed infective period. The analysis includes both local and global stability of equilibria.
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Received: 7 May 1999 / Revised version: 24 November 1999 /¶Published online: 7 June 2000
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van den Driessche, P., Watmough, J. A simple SIS epidemic model with a backward bifurcation. J Math Biol 40, 525–540 (2000). https://doi.org/10.1007/s002850000032
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DOI: https://doi.org/10.1007/s002850000032