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The quasi-stationary distribution of the closed endemic sis model

Published online by Cambridge University Press:  01 July 2016

Ingemar Nåsell*
Affiliation:
The Royal Institute of Technology, Stockholm
*
Postal address: Department of Mathematics, The Royal Institute of Technology, S-l0044 Stockholm, Sweden.

Abstract

The quasi-stationary distribution of the closed stochastic SIS model changes drastically as the basic reproduction ratio R0 passes the deterministic threshold value 1. Approximations are derived that describe these changes. The quasi-stationary distribution is approximated by a geometric distribution (discrete!) for R0 distinctly below 1 and by a normal distribution (continuous!) for R0 distinctly above 1. Uniformity of the approximation with respect to R0 allows one to study the transition between these two extreme distributions. We also study the time to extinction and the invasion and persistence thresholds of the model.

Type
General Applied Probablity
Copyright
Copyright © Applied Probability Trust 1996 

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References

Anderson, R. M. and May, R. M. (1991) Infectious Diseases of Humans; Dynamics and Control. Oxford University Press, Oxford.Google Scholar
Bartholomew, D. J. (1976) Continuous time diffusion models with random duration of interest. J. Math. Social. 4, 187199.Google Scholar
Cavender, J. A. (1978) Quasi-stationary distributions of birth-and-death processes. Adv. Appl. Prob. 10, 570586.CrossRefGoogle Scholar
Darroch, J. N. and Seneta, E. (1967) On quasi-stationary distributions in absorbing continuous-time finite Markov chains. J. Appl. Prob. 4, 192196.Google Scholar
Flajolet, P., Grabner, P. J., Kirschenhofer, P. and Prodinger, H. (1995) On Ramanujan's Q-Function. J. Comp. Appl. Math 58, 103116.Google Scholar
Jacquez, J. A. and Simon, C. P. (1993) The stochastic SI model with recruitment and deaths. I. Comparisons with the closed SIS model. Math. Biosci. 117, 77125.CrossRefGoogle ScholarPubMed
Karlin, S. and Taylor, H. M. (1975) A First Course in Stochastic Processes. 2nd Edition. Academic Press, New York.Google Scholar
Knuth, D. E. (1973) The Art of Computer Programming. Volume 1: Fundamental Algorithms. Addison-Wesley, Reading, MA.Google Scholar
Kryscio, R. J. and Lefèvre, C. (1989) On the extinction of the S-I-S stochastic logistic epidemic. J. Appl. Prob. 27, 685694.Google Scholar
Nåsell, I. (1991) On the quasi-stationary distribution of the Ross malaria model. Math. Biosci. 107, 187208.Google Scholar
Nåsell, I. (1995) The threshold concept in stochastic epidemic and endemic models. In Epidemic Models: Their Structure and Relation to Data. ed. Mollison, D.. Cambridge University Press, Cambridge.Google Scholar
Norden, R. H. (1982) On the distribution of the time to extinction in the stochastic logistic population model. Adv. Appl. Prob. 14, 687708.Google Scholar
Olver, F. W. J. (1974) Asymptotics and Special Functions. Academic Press, New York.Google Scholar
Oppenheim, I., Shuler, K. E. and Weiss, G. H. (1977) Stochastic theory of nonlinear rate processes with multiple stationary states. Physica 88A, 191214.Google Scholar
Picard, P. (1965) Sur les modèles stochastique logistiques en démographie. Ann. Inst. Henri Poincaré B II, 151172.Google Scholar
Pollett, P. K. and Stewart, D. E. (1994) An efficient procedure for computing quasistationary distributions of Markov chains with sparse transition structure. Adv. Appl. Prob. 26, 6879.Google Scholar
Ramanujan, S. (1911) Question 294. J. Indian Math. Soc. 3, 128.Google Scholar
Temme, N. M. (1975) Uniform asymptotic expansions of the incomplete gamma functions and the incomplete beta function. Math. Comput 29, 11091114.Google Scholar
Temme, N. M. (1979) The asymptotic expansion of the incomplete gamma functions. SIAM J. Math. Anal. 10, 757766.Google Scholar
Van Herwaarden, O. A. and Grasman, J. (1995) Stochastic epidemics: major outbreaks and the duration of the epidemic period. J. Math. Biol. 33, 581601.Google Scholar
Weiss, G. H. and Dishon, M. (1971) On the asymptotic behavior of the stochastic and deterministic models of an epidemic. Math. Biosci. 11, 261265.Google Scholar