This study presents, as a proof-of-concept, a mathematical model describing the transmission dynamics of cystic echinococcosis. This neglected zoonosis is caused by the larval stage of Echinococcus granulosus s.l. involving dogs and sheep as definitive hosts and sheep as intermediate hosts. The model incorporates the dual role of humans as final hosts and as active participants in the parasite's transmission cycle through practices such as feeding dogs with infected viscera. A system of nine ordinary differential equations represents human subpopulations (children and adults) and the concentration of viable parasite eggs. The basic reproductive number ($ R_0 $) was computed via the next-generation matrix approach, and bifurcation analysis indicated a forward bifurcation at $ R_{0} = 1, $ confirming that $ R_{0} < 1 $ ensures disease control. Global sensitivity analysis using Sobol indices identified the infestation rate ($ \beta $) and adult transmission rate ($ \beta_{AG} $) as the most influential parameters, explaining 35.9% and 29.9% of $ R_0 $ variance, respectively. These findings highlight that interventions reducing $ \beta $ and $ \beta_{AG} $ may effectively decrease human infection rates.
Citation: Richard Lagos, Andrei González-Galeano, Jaleydi Cárdenas-Poblador, Álvaro Mella-Parra, María Esther Leyva-Borges. Impact of human behavior on the perpetuation of the Echinococcus granulosus life cycle: A mathematical approach[J]. Mathematical Biosciences and Engineering, 2026, 23(3): 776-798. doi: 10.3934/mbe.2026030
This study presents, as a proof-of-concept, a mathematical model describing the transmission dynamics of cystic echinococcosis. This neglected zoonosis is caused by the larval stage of Echinococcus granulosus s.l. involving dogs and sheep as definitive hosts and sheep as intermediate hosts. The model incorporates the dual role of humans as final hosts and as active participants in the parasite's transmission cycle through practices such as feeding dogs with infected viscera. A system of nine ordinary differential equations represents human subpopulations (children and adults) and the concentration of viable parasite eggs. The basic reproductive number ($ R_0 $) was computed via the next-generation matrix approach, and bifurcation analysis indicated a forward bifurcation at $ R_{0} = 1, $ confirming that $ R_{0} < 1 $ ensures disease control. Global sensitivity analysis using Sobol indices identified the infestation rate ($ \beta $) and adult transmission rate ($ \beta_{AG} $) as the most influential parameters, explaining 35.9% and 29.9% of $ R_0 $ variance, respectively. These findings highlight that interventions reducing $ \beta $ and $ \beta_{AG} $ may effectively decrease human infection rates.
| [1] |
T. Mohammed, S. L. Ezzat, H. S. Abdullah, S. J. Qadir, A. K. Hamad, S. A. Faraj, et al., Echinococcus granulosus in environmental samples: A cross-sectional molecular study, Barw Med. J., 3 (2025), 9–14. https://doi.org/10.58742/bmj.vi.200 doi: 10.58742/bmj.vi.200
|
| [2] |
G. Acosta-Jamett, F. Tamarozzi, N. Castro, S. J. Santivanez, R. E. Laurente, C. Mazzi, et al., Community risk of environmental-borne cystic echinococcosis transmission in South America: Results from the multistep cross-sectional and case-control PERITAS study, PLoS Negl. Trop. Dis., 19 (2025), 1–14. https://doi.org/10.1371/journal.pntd.0013382 doi: 10.1371/journal.pntd.0013382
|
| [3] |
E. Serra, G. Masu, V. Chisu, S. Cappai, G. Masala, F. Loi, et al., Environmental contamination by Echinococcus spp. eggs as a risk for human health in educational farms of Sardinia, Italy, Vet. Sci., 9 (2022), 143. https://doi.org/10.3390/vetsci9030143 doi: 10.3390/vetsci9030143
|
| [4] |
C. A. Alvarez, A. Mathis, P. Deplazes, Assessing the contamination of food and the environment with Taenia and Echinococcus eggs and their zoonotic transmission, Curr. Clin. Microbiol. Rep., 5 (2018), 154–163. https://doi.org/10.1007/s40588-018-0091-0 doi: 10.1007/s40588-018-0091-0
|
| [5] |
K. Federer, M. T. Armua-Fernandez, F. Gori, S. Hoby, C. Wenker, P. Deplazes, Detection of taeniid (Taenia spp., Echinococcus spp.) eggs contaminating vegetables and fruits sold in European markets and the risk for metacestode infections in captive primates, Int. J. Parasitol.: Parasites Wildl., 5 (2016), 249–253. https://doi.org/10.1016/j.ijppaw.2016.07.002 doi: 10.1016/j.ijppaw.2016.07.002
|
| [6] |
Z. Valieva, N. Sarsembaeva, A. Valdovska, A. E. Ussenbayev, Impact of Echinococcosis on quality of sheep meat in the south eastern Kazakhstan, Asian-Australas. J. Anim. Sci., 27 (2014), 391–397. https://doi.org/10.5713/ajas.2013.13386 doi: 10.5713/ajas.2013.13386
|
| [7] |
E. Larrieu, G. Mujica, C. G. Gauci, K. Vizcaychipi, M. Seleiman, E. Herrero, et al., Pilot field trial of the EG95 vaccine against ovine cystic Echinococcosis in Rio Negro, Argentina: Second study of impact, PLoS Negl. Trop. Dis., 9 (2015), 1–10. https://doi.org/10.1371/journal.pntd.0004134 doi: 10.1371/journal.pntd.0004134
|
| [8] | Manual para el diagnóstico, tratamiento, prevención y control de la Hidatidosis en Chile, 2015. Available from: https://diprece.minsal.cl/wrdprss_minsal/wp-content/uploads/2016/02/Manual-Hidatidosis.pdf. |
| [9] |
M. Reza, S. Mohammad, M. Ali, S. Nasibi, S. Shamsaddini, F. Mollaee, et al., Surface water contamination with Echinococcus granulosus eggs in southeast of iran: Significance and public health implications, J. Water Health, 23 (2025), 981–990. https://doi.org/10.2166/wh.2025.244 doi: 10.2166/wh.2025.244
|
| [10] |
R. Barosi, G. Umhang, Presence of Echinococcus eggs in the environment and food: A review of current data and future prospects, Parasitology, 13 (2024), 1416–1431. https://doi.org/10.1017/s0031182024000945 doi: 10.1017/s0031182024000945
|
| [11] |
J. F. Alvarez, R. Ruiz, J. Ríos, C. A. Alvarez, Molecular detection of Echinococcus granulosus sensu stricto in environmental dog faecal samples from the Magallanes region, Patagonia, Chile, Parasitologia, 1 (2021), 238–246. https://doi.org/10.3390/parasitologia1040025 doi: 10.3390/parasitologia1040025
|
| [12] |
R. Lagos, J. P. Gutiérrez-Jara, B. Cancino-Faure, L. Y. Lara-Díaz, Sensitivity analysis of a mathematical model for the transmission of cystic echinococcosis, J. Phys. Conf. Ser., 3117 (2025), 012011. https://doi.org/10.1088/1742-6596/3117/1/012011 doi: 10.1088/1742-6596/3117/1/012011
|
| [13] |
R. Lagos, J. P. Gutiérrez-Jara, B. Cancino-Faure, L. Y. Lara-Díaz, A. González-Galeano, Breaking the cycle of Echinococcosis: A mathematical modeling approach, Trop. Med. Infect. Dis., 10 (2025), 101. https://doi.org/10.3390/tropicalmed10040101 doi: 10.3390/tropicalmed10040101
|
| [14] |
R. Lagos, J. P. Gutiérrez-Jara, B. Cancino-Faure, L. Y. Lara-Díaz, A. Coronel, The role of host mobility in the transmission and spread of Echinococcus granulosus: A Chile-based mathematical modeling approach PLoS Negl. Trop. Dis., 19 (2025), e0012948. https://doi.org/10.1371/journal.pntd.0012948 doi: 10.1371/journal.pntd.0012948
|
| [15] |
J. A. M. Atkinson, G. M. Williams, L. Yakob, A. C. A. Clements, T. S. Barnes, D. McManus, et al., Synthesising 30 years of mathematical modelling of Echinococcus transmission, PLoS Negl. Trop. Dis., 7 (2013), e2386. https://doi.org/10.1371/journal.pntd.0002386 doi: 10.1371/journal.pntd.0002386
|
| [16] |
G. B. Birhan, J. M. W. Munganga, A. S. Hassan, Mathematical modeling of Echinococcosis in humans, dogs, and sheep, J. Appl. Math., 2020 (2020), 8482696. https://doi.org/10.1155/2020/8482696 doi: 10.1155/2020/8482696
|
| [17] |
K. Wang, X. Zhang, Z. Jin, H. Ma, Z. Teng, L. Wang, Modeling and analysis of the transmission of Echinococcosis with application to Xinjiang Uygur autonomous region of China, J. Theor. Biol., 333 (2013), 78–90. https://doi.org/10.1016/j.jtbi.2013.04.020 doi: 10.1016/j.jtbi.2013.04.020
|
| [18] |
C. S. Chacha, M. A. Stephano, J. I. Irunde, J. A. Mwasunda, Cystic echinococcosis dynamics in dogs, humans and cattle: Deterministic and stochastic modeling, Results Phys., 51 (2023), 106697. https://doi.org/10.1016/j.rinp.2023.106697 doi: 10.1016/j.rinp.2023.106697
|
| [19] |
L. Wu, B. Song, W. Du, J. Lou, Mathematical modelling and control of echinococcus in Qinghai province, China, Math. Biosci. Eng., 10 (2013), 425–444. https://doi.org/10.3934/mbe.2013.10.425 doi: 10.3934/mbe.2013.10.425
|
| [20] |
B. Getachew, J. M. W. Munganga, A. S. Hassan, Mathematical modelling of echinococcosis in human, dogs and sheep with intervention, J. Biol. Dyn., 16 (2022), 439–463. https://doi.org/10.1080/17513758.2022.2081368 doi: 10.1080/17513758.2022.2081368
|
| [21] |
A. González-Galeano, I. Barradas, J. Villavicencio, Beyond R0: Exploring new approaches, Rev. Modelamiento Mat. Sistemas Biol., 3 (2023), e23R08. https://doi.org/10.58560/rmmsb.v03.n02.023.09 doi: 10.58560/rmmsb.v03.n02.023.09
|
| [22] |
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
|
| [23] |
W. Wang, Backward bifurcation of an epidemic model with treatment, Math. Biosci., 201 (2006), 58–71. https://doi.org/10.1016/j.mbs.2005.12.022 doi: 10.1016/j.mbs.2005.12.022
|
| [24] |
J. G. Villavicencio, J. I. Barradas, J. C. Hernández, A basic backward Bifurcation model in epidemiology, Appl. Math. Sci., 7 (2013), 5327–5340. https://doi.org/10.12988/AMS.2013.36324 doi: 10.12988/AMS.2013.36324
|
| [25] |
C. Castillo-Chavez, B. Song, Dynamical models of tuberculosis and their applications, Math. Biosci. Eng., 1 (2004), 361–404. https://doi.org/10.3934/mbe.2004.1.361 doi: 10.3934/mbe.2004.1.361
|
| [26] | The MathWorks, MATLAB and simulink for engineered systems, 2023. Available from: https://www.mathworks.com. |
| [27] | B. J. Bogitsh, C. E. Carter, T. N. Oeltmann, Human Parasitology, 5$^{th}$ edition, Academic Press, 2019. https://doi.org/10.1016/C2016-0-00382-0 |
| [28] | A. Saltelli, M. Ratto, T. Andres, F. Campolongo, J. Cariboni, D. Gatelli, et al., Global Sensitivity Analysis: The Primer, John Wiley & Sons, Chichester, 2008. https://doi.org/10.1002/9780470725184 |
| [29] |
C. Alvarez, F. Fredes, M. Torres, G. Acosta-Jamett, J. Alvarez, C. Pavletic, et al., First meeting "Cystic echinococcosis in Chile, update in alternatives for control and diagnostics in animals and humans", Parasites Vectors, 9 (2016), 502. https://doi.org/10.1186/s13071-016-1792-y doi: 10.1186/s13071-016-1792-y
|