MBI Publications

MBI Publications for Suzanne Robertson (7)

  • S. Robertson and I. Hamilton
    Habitat selection under the risk of infectious disease
    (Under Revision)

    Abstract

  • S. Robertson and J. Cushing
    Spatial segregation in stage-structured populations with an application to Tribolium
    Journal of Biological DynamicsVol. 5 No. 5 (2011) pp. 398-409

    Abstract

  • S. Robertson and J. Cushing
    A bifurcation analysis of stage-structured density dependent integrodifference equations
    Journal of Mathematical Analysis and ApplicationsVol. 388 (1) (2011) pp. 490-499

    Abstract

  • S. Robertson and I. Hamilton
    Ideal free habitat selection under the risk of infectious disease transmission
    (2011) (Submitted)

    Abstract

  • M. Eisenberg, S. Robertson and J. Tien
    Identifiability and estimation of multiple transmission pathways in waterborne disease
    (2011) (Under Revision)

    Abstract

  • J. Cushing, R. Costantino and S. Robertson
    Life stages: interactions and spatial patterns
    Bulletin of Mathematical BiologyVol. 74 (2012) pp. 491-508

    Abstract

  • M. Eisenberg, S. Robertson and J. Tien
    Identifiability and estimation of multiple transmission pathways in cholera and waterborne disease.
    Journal of theoretical biologyVol. 324 (2013) pp. 84-102

    Abstract

    Cholera and many waterborne diseases exhibit multiple characteristic timescales or pathways of infection, which can be modeled as direct and indirect transmission. A major public health issue for waterborne diseases involves understanding the modes of transmission in order to improve control and prevention strategies. An important epidemiological question is: given data for an outbreak, can we determine the role and relative importance of direct vs. environmental/waterborne routes of transmission? We examine whether parameters for a differential equation model of waterborne disease transmission dynamics can be identified, both in the ideal setting of noise-free data (structural identifiability) and in the more realistic setting in the presence of noise (practical identifiability). We used a differential algebra approach together with several numerical approaches, with a particular emphasis on identifiability of the transmission rates. To examine these issues in a practical public health context, we apply the model to a recent cholera outbreak in Angola (2006). Our results show that the model parameters-including both water and person-to-person transmission routes-are globally structurally identifiable, although they become unidentifiable when the environmental transmission timescale is fast. Even for water dynamics within the identifiable range, when noisy data are considered, only a combination of the water transmission parameters can practically be estimated. This makes the waterborne transmission parameters difficult to estimate, leading to inaccurate estimates of important epidemiological parameters such as the basic reproduction number (R0). However, measurements of pathogen persistence time in environmental water sources or measurements of pathogen concentration in the water can improve model identifiability and allow for more accurate estimation of waterborne transmission pathway parameters as well as R0. Parameter estimates for the Angola outbreak suggest that both transmission pathways are needed to explain the observed cholera dynamics. These results highlight the importance of incorporating environmental data when examining waterborne disease.

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