In this paper, we introduce a general numerical method to approximate the reproduction numbers of a large class of multi-group, age-structured, population models with a finite age span. To provide complete flexibility in the definition of the birth and transition processes, we propose an equivalent formulation for the age-integrated state within the extended space framework. Then, we discretize the birth and transition operators via pseudospectral collocation. We discuss applications to epidemic models with continuous and piecewise continuous rates, with different interpretations of the age variable (e.g., demographic age, infection age and disease age) and the transmission terms (e.g., horizontal and vertical transmission). The tests illustrate that the method can compute different reproduction numbers, including the basic and type reproduction numbers as special cases.
Citation: Simone De Reggi, Francesca Scarabel, Rossana Vermiglio. Approximating reproduction numbers: a general numerical method for age-structured models[J]. Mathematical Biosciences and Engineering, 2024, 21(4): 5360-5393. doi: 10.3934/mbe.2024236
In this paper, we introduce a general numerical method to approximate the reproduction numbers of a large class of multi-group, age-structured, population models with a finite age span. To provide complete flexibility in the definition of the birth and transition processes, we propose an equivalent formulation for the age-integrated state within the extended space framework. Then, we discretize the birth and transition operators via pseudospectral collocation. We discuss applications to epidemic models with continuous and piecewise continuous rates, with different interpretations of the age variable (e.g., demographic age, infection age and disease age) and the transmission terms (e.g., horizontal and vertical transmission). The tests illustrate that the method can compute different reproduction numbers, including the basic and type reproduction numbers as special cases.
[1] | R. M. Anderson, R. M. May, Infectious Diseases of Humans: Dynamics and Control, Oxford University Press, 1991. |
[2] | J. A. P. Heesterbeek, A brief history of $R_0$ and a recipe for its calculation, Acta Biotheor., 50 (2002), 189–204. https://doi.org/10.1023/a:1016599411804 doi: 10.1023/a:1016599411804 |
[3] | O. Diekmann, J. A. P. Heesterbeek, J. A. J. Metz, On the definition and the computation of the basic reproduction ratio $R_0$ in models for infectious diseases in heterogeneous populations, J. Math. Biol., 28 (1990), 365–382. https://doi.org/10.1007/BF00178324 doi: 10.1007/BF00178324 |
[4] | L. Pellis, P. J. Birrell, J. Blake, C. E. Overton, F. Scarabel, H. B. Stage et al., Estimation of reproduction numbers in real time: conceptual and statistical challenges, J. R. Stat. Soc. Ser. A Stat. Soc., 185 (2022), S112–S130. https://doi.org/10.1111/rssa.12955 doi: 10.1111/rssa.12955 |
[5] | M. G. Roberts, J. A. P. Heesterbeek, A new method for estimating the effort required to control an infectious disease, Proc. Royal Soc. B, 270 (2003), 1359–1364. https://doi.org/10.1098/rspb.2003.2339 doi: 10.1098/rspb.2003.2339 |
[6] | J. A. P. Heesterbeek, M. G. Roberts, The type-reproduction number $T$ in models for infectious disease control, Math. Biosci., 206 (2007), 3–10. https://doi.org/10.1016/j.mbs.2004.10.013 doi: 10.1016/j.mbs.2004.10.013 |
[7] | H. Inaba, H. Nishiura, The state-reproduction number for a multistate class age structured epidemic system and its application to the asymptomatic transmission model, Math. Biosci., 216 (2008), 77–89. https://doi.org/10.1016/j.mbs.2008.08.005 doi: 10.1016/j.mbs.2008.08.005 |
[8] | H. Inaba, Age-Structured Population Dynamics in Demography and Epidemiology, Springer, Singapore, 2017. https://doi.org/10.1007/978-981-10-0188-8 |
[9] | Z. Shuai, J. Heesterbeek, P. van den Driessche, Extending the type reproduction number to infectious disease control targeting contacts between types, J. Math. Biol., 67 (2013), 1067–1082. https://doi.org/10.1007/s00285-012-0579-9 doi: 10.1007/s00285-012-0579-9 |
[10] | M. A. Lewis, Z. Shuai, P. van den Driessche, A general theory for target reproduction numbers with applications to ecology and epidemiology, J. Math. Biol., 78 (2019), 2317–2339. https://doi.org/10.1007/s00285-019-01345-4 doi: 10.1007/s00285-019-01345-4 |
[11] | H. R. Thieme, Spectral bound and reproduction number for infinite-dimensional population structure and time heterogeneity, SIAM J. Appl. Math., 70 (2009), 188–211. https://doi.org/10.1137/080732870 doi: 10.1137/080732870 |
[12] | O. Diekmann, J. A. P. Heesterbeek, M. G. Roberts, The construction of next-generation matrices for compartmental epidemic models, J. R. Soc. Interface., 7 (2010), 873–885. https://doi.org/10.1098/rsif.2009.0386 doi: 10.1098/rsif.2009.0386 |
[13] | P. van den Driessche, J. Watmough, Reproduction numbers and sub-threshold endemic equilibria for compartmental models of disease transmission, Math. Biosci., 180 (2002), 29–48. https://doi.org/10.1016/s0025-5564(02)00108-6 doi: 10.1016/s0025-5564(02)00108-6 |
[14] | J. Li, D. Blakeley, R. J. Smith?, The failure of $R_0$, Comput. Math. Methods Med., 2011 (2011). https://doi.org/10.1155/2011/527610 |
[15] | J. M. Cushing, O. Diekmann, The many guises of $R_0$ (a didactic note), J. Theor. Biol., 404 (2016), 295–302. https://doi.org/10.1016/j.jtbi.2016.06.017 doi: 10.1016/j.jtbi.2016.06.017 |
[16] | A. F. Brouwer, Why the Spectral Radius? An intuition-building introduction to the basic reproduction number, Bull. Math. Biol., 84 (2022), 96. https://doi.org/10.1007/s11538-022-01057-9 doi: 10.1007/s11538-022-01057-9 |
[17] | C. Barril, À. Calsina, S. Cuadrado, J. Ripoll, On the basic reproduction number in continuously structured populations, Math. Methods Appl. Sci., 44 (2021), 799–812. https://doi.org/10.1002/mma.6787 doi: 10.1002/mma.6787 |
[18] | C. Barril, À. Calsina, J. Ripoll, A practical approach to $R_0$ in continuous-time ecological models, Math. Methods Appl. Sci., 41 (2018), 8432–8445. https://doi.org/10.1002/mma.4673 doi: 10.1002/mma.4673 |
[19] | C. Barril, P. A. Bliman, S. Cuadrado, Final Size for Epidemic Models with Asymptomatic Transmission, Bull. Math. Biol., 85 (2023), 52. https://doi.org/10.1007/s11538-023-01159-y doi: 10.1007/s11538-023-01159-y |
[20] | H. R. Thieme, Semiflows generated by Lipschitz perturbations of non-densely defined operators, Differ. Integral Equ., 3 (1990), 1035–1066. https://doi.org/10.57262/die/1379101977 doi: 10.57262/die/1379101977 |
[21] | H. Inaba, Mathematical analysis of an age-structured SIR epidemic model with vertical transmission, Discrete Contin. Dyn. Syst. B, 6 (2006), 69–96. https://doi.org/10.3934/dcdsb.2006.6.69 doi: 10.3934/dcdsb.2006.6.69 |
[22] | M. G. Krein, M. A. Rutman, Linear operators leaving invariant a cone in a Banach space, Uspekhi Mat. Nauk., 3 (1948), 3–95. |
[23] | W. Guo, M. Ye, X. Li, A. Meyer-Baese, Q. Zhang, A theta-scheme approximation of basic reproduction number for an age-structured epidemic system in a finite horizon, Math. Biosci. Eng., 16 (2019), 4107–4121. https://doi.org/10.3934/mbe.2019204 doi: 10.3934/mbe.2019204 |
[24] | T. Kuniya, Numerical approximation of the basic reproduction number for a class of age-structured epidemic models, Appl. Math. Lett., 73 (2017), 106–112. https://doi.org/10.1016/j.aml.2017.04.031 doi: 10.1016/j.aml.2017.04.031 |
[25] | D. Breda, S. De Reggi, F. Scarabel, R. Vermiglio, J. Wu, Bivariate collocation for computing $R_0$ in epidemic models with two structures, Comput. Math. with Appl., 116 (2022), 15–24. https://doi.org/10.1016/j.camwa.2021.10.026 doi: 10.1016/j.camwa.2021.10.026 |
[26] | D. Breda, F. Florian, J. Ripoll, R. Vermiglio, Efficient numerical computation of the basic reproduction number for structured populations, J. Comput. Appl. Math., 384 (2021), 113165. https://doi.org/10.1016/j.cam.2020.113165 doi: 10.1016/j.cam.2020.113165 |
[27] | D. Breda, T. Kuniya, J. Ripoll, R. Vermiglio, Collocation of next-generation operators for computing the basic reproduction number of structured populations, J. Sci. Comput., 85 (2020), 1–33. https://doi.org/10.1007/s10915-020-01339-1 doi: 10.1007/s10915-020-01339-1 |
[28] | L. Trefethen, Spectral Methods in MATLAB, Software Environ. Tools, Society for Industrial and Applied Mathematics, Philadelphia, 2000. https://doi.org/10.1137/1.9780898719598 |
[29] | A. Andò, S. De Reggi, D. Liessi, F. Scarabel, A pseudospectral method for investigating the stability of linear population models with two physiological structures, Math. Biosci. Eng., 20 (2023), 4493–4515. https://doi.org/10.3934/mbe.2023208 doi: 10.3934/mbe.2023208 |
[30] | D. Breda, S. De Reggi, R. Vermiglio, A numerical method for the stability analysis of linear age-structured models with nonlocal diffusion, SIAM J. Sci. Comput., In press. Available from: https://arXiv.org/abs/2304.10835v2. |
[31] | F. Scarabel, D. Breda, O. Diekmann, M. Gyllenberg, R. Vermiglio, Numerical bifurcation analysis of physiologically structured population models via pseudospectral approximation, Vietnam J. Math., 49 (2021), 37–67. https://doi.org/10.1007/s10013-020-00421-3 doi: 10.1007/s10013-020-00421-3 |
[32] | F. Scarabel, O. Diekmann, R. Vermiglio, Numerical bifurcation analysis of renewal equations via pseudospectral approximation, J. Comput. Appl. Math., 397 (2021), 113611. https://doi.org/10.1016/j.cam.2021.113611 doi: 10.1016/j.cam.2021.113611 |
[33] | S. De Reggi, F. Scarabel, R. Vermiglio, On the convergence of the pseudospectral approximation of reproduction numbers for age-structured models, in preparation. |
[34] | H. Inaba, On the definition and the computation of the type-reproduction number $T$ for structured populations in heterogeneous environments, J. Math. Biol., 66 (2013), 1065–1097. https://doi.org/10.1007/s00285-012-0522-0 doi: 10.1007/s00285-012-0522-0 |
[35] | P. van den Driessche, Reproduction numbers of infectious disease models, Infect. Dis. Model., 2 (2017), 288–303. https://doi.org/10.1016/j.idm.2017.06.002 doi: 10.1016/j.idm.2017.06.002 |
[36] | K. J. Engel, R. Nagel, One-Parameter Semigroups for Linear Evolution Equations, no. 194 in Grad. Texts in Math., Springer, New York, 2000. https://doi.org/10.1007/b97696 |
[37] | D. Breda, S. Maset, R. Vermiglio, Approximation of eigenvalues of evolution operators for linear retarded functional differential equations, SIAM J. Numer. Anal., 50 (2012), 1456–1483. https://doi.org/10.1137/100815505 doi: 10.1137/100815505 |
[38] | J. P. Boyd, Chebyshev and Fourier Spectral Methods, 2nd edition, Dover, Mineola, NY, 2001, reprint of the Springer, Berlin, 1989 edition. |
[39] | L. N. Trefethen, Approximation Theory and Approximation Practice, Society for Industrial and Applied Mathematics, Philadelphia, 2013. |
[40] | K. Xu, The Chebyshev points of the first kind, Appl. Numer. Math., 102 (2016), 17–30. https://doi.org/10.1016/j.apnum.2015.12.002 doi: 10.1016/j.apnum.2015.12.002 |
[41] | O. Diekmann, F. Scarabel, R. Vermiglio, Pseudospectral discretization of delay differential equations in sun-star formulation: results and conjectures, Discrete Contin. Dyn. Syst. S, 13 (2020), 2575–2602. https://doi.org/10.3934/dcdss.2020196 doi: 10.3934/dcdss.2020196 |
[42] | H. Inaba, Endemic threshold analysis for the Kermack-McKendrick reinfection model, Josai Math. Monogr., 9 (2016), 105–133. https://doi.org/10.20566/13447777_9_105 doi: 10.20566/13447777_9_105 |
[43] | G. Mastroianni, G. V. Milovanović, Interpolation Processes: Basic Theory and Applications, Springer, Berlin, 2008. https://dx.doi.org/10.1007/978-3-540-68349-0 |
[44] | C. W. Clenshaw, A. R. Curtis, A method for numerical integration on an automatic computer, Numer. Math. (Heidelb), 2 (1960), 197–205. https://doi.org/10.1007/BF01386223 doi: 10.1007/BF01386223 |
[45] | L. N. Trefethen, Is Gauss quadrature better than Clenshaw–Curtis?, SIAM Rev., 50 (2008), 67–87. https://doi.org/10.1137/060659831 doi: 10.1137/060659831 |
[46] | F. Scarabel, L. Pellis, N. H. Ogden, J. Wu, A renewal equation model to assess roles and limitations of contact tracing for disease outbreak control, R. Soc. Open Sci., 8 (2021), 202091. https://doi.org/10.1101/2020.12.27.20232934 doi: 10.1101/2020.12.27.20232934 |
[47] | C. E. Overton, H. B. Stage, S. Ahmad, J. Curran-Sebastian, P. Dark, R. Das et al., Using statistics and mathematical modelling to understand infectious disease outbreaks: COVID-19 as an example, Infect. Dis. Model., 5 (2020), 409–441. https://doi.org/10.1016/j.idm.2020.06.008 doi: 10.1016/j.idm.2020.06.008 |
[48] | L. Ferretti, C. Wymant, M. Kendall, L. Zhao, A. Nurtay, L. Abeler-Dörner et al., Quantifying SARS-CoV-2 transmission suggests epidemic control with digital contact tracing, Science, 368 (2020), eabb6936. https://doi.org/10.1126/science.abb6936 doi: 10.1126/science.abb6936 |
[49] | Z. Qiu, X. Li, M. Martcheva, Multi-strain persistence induced by host age structure, J. Math. Anal. Appl., 391 (2012), 595–612. https://doi.org/10.1016/j.jmaa.2012.02.052 doi: 10.1016/j.jmaa.2012.02.052 |
[50] | C. Castillo-Chavez, H. W. Hethcote, V. Andreasen, S.A. Levin, W. M. Liu, Epidemiological models with age structure, proportionate mixing, and cross-immunity, J. Math. Biol., 27 (1989), 233–258. https://doi.org/10.1007/bf00275810 doi: 10.1007/bf00275810 |
[51] | C. Barril, À. Calsina, S. Cuadrado, J. Ripoll, Reproduction number for an age of infection structured model, Math. Model. Nat. Phenom., 16 (2021), 42. https://doi.org/10.1051/mmnp/2021033 doi: 10.1051/mmnp/2021033 |
[52] | Center for Disease Control and Prevention (CDC), Rubella (German Measles, Three-Day Measles), 2020. Available from: https://www.cdc.gov/rubella/about/index.html. |
[53] | World Health Organization (WHO), Rubella, 2019. Available from: https://www.who.int/en/news-room/fact-sheets/detail/rubella |
[54] | R. M. Anderson, B. T. Grenfell, Quantitative investigations of different vaccination policies for the control of congenital rubella syndrome (CRS) in the United Kingdom, Epidemiol. Infect., 96 (1986), 305–333. https://doi.org/10.1017/s0022172400066079 doi: 10.1017/s0022172400066079 |
[55] | R. M. Anderson, R. M. May, Vaccination against rubella and measles: quantitative investigations of different policies, Epidemiol. Infect., 90 (1983), 259–325. https://doi.org/10.1017/s002217240002893x doi: 10.1017/s002217240002893x |
[56] | R. M. Anderson, R. M. May, Age-related changes in the rate of disease transmission: implications for the design of vaccination programmes, Epidemiol. Infect., 94 (1985), 365–436. https://doi.org/10.1017/s002217240006160x doi: 10.1017/s002217240006160x |
[57] | H. Kang, X. Huo, S. Ruan, On first-order hyperbolic partial differential equations with two internal variables modeling population dynamics of two physiological structures, Ann. di Mat. Pura ed Appl., 200 (2021), 403–452. https://doi.org/10.1007/s10231-020-01001-5 doi: 10.1007/s10231-020-01001-5 |
[58] | G. Webb, Dynamics of populations structured by internal variables, Math. Zeitschrift, 189 (1985), 319–335. https://doi.org/10.1007/BF01164156 doi: 10.1007/BF01164156 |
[59] | À. Calsina, O. Diekmann, J. Z. Farkas, Structured populations with distributed recruitment: from PDE to delay formulation, Math. Methods Appl. Sci., 39 (2016), 5175–5191. https://doi.org/10.1002/mma.3898 doi: 10.1002/mma.3898 |
[60] | M. Gyllenberg, F. Scarabel, R. Vermiglio, Equations with infinite delay: Numerical bifurcation analysis via pseudospectral discretization, Appl. Math. Comput., 333 (2018), 490–505. https://doi.org/10.1016/j.amc.2018.03.104 doi: 10.1016/j.amc.2018.03.104 |
[61] | F. Scarabel, R. Vermiglio, Equations with infinite delay: pseudospectral discretization for numerical stability and bifurcation in an abstract framework, arXiv preprint arXiv: 2306.13351. |
[62] | M. Iannelli, Mathematical Theory of Age-Structured Population Dynamics, Giardini Editori e Stampatori, Pisa, 1995. |