DOI: 10.21276/sjpms.2018.5.2.1

Pages: 92-97

The basic reproduction number importantly summaries the dynamics of an infectious disease in human populations. This parameter is called a threshold parameter. For an infection to invade a population should be greater than 1. In epidemiological studies, intervention seeks to lower the value of to below 1 so that the disease dies out. However, simple modelling of malaria revealed that, theoretically it is possible for an infection to persist indefinitely even if an intervention has reduced below 1. If this happens, we call it bistable equilibrium. In this work, we focused mainly on the analysis of the Disease-Free Equilibrium Point [DFEP] to see the circumstances surrounding the propagation of an infectious disease. We found that the disease dies out if the reproduction number is less than 1.