A Habitat-Based Model for the Spread of Hantavirus between Reservoir and Spillover Species

Texas Tech University, Department of Mathematics and Statistics, Lubbock, TX 79409, USA.
Journal of Theoretical Biology (Impact Factor: 2.12). 08/2009; 260(4):510-22. DOI: 10.1016/j.jtbi.2009.07.009
Source: PubMed


New habitat-based models for spread of hantavirus are developed which account for interspecies interaction. Existing habitat-based models do not consider interspecies pathogen transmission, a primary route for emergence of new infectious diseases and reservoirs in wildlife and man. The modeling of interspecies transmission has the potential to provide more accurate predictions of disease persistence and emergence dynamics. The new models are motivated by our recent work on hantavirus in rodent communities in Paraguay. Our Paraguayan data illustrate the spatial and temporal overlaps among rodent species, one of which is the reservoir species for Jabora virus and others which are spillover species. Disease transmission occurs when their habitats overlap. Two mathematical models, a system of ordinary differential equations (ODE) and a continuous-time Markov chain (CTMC) model, are developed for spread of hantavirus between a reservoir and a spillover species. Analysis of a special case of the ODE model provides an explicit expression for the basic reproduction number, R(0), such that if R(0)<1, then the pathogen does not persist in either population but if R(0)>1, pathogen outbreaks or persistence may occur. Numerical simulations of the CTMC model display sporadic disease incidence, a new behavior of our habitat-based model, not present in other models, but which is a prominent feature of the seroprevalence data from Paraguay. Environmental changes that result in greater habitat overlap result in more encounters among various species that may lead to pathogen outbreaks and pathogen establishment in a new host.

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    • "Cross-species transmission is a significant process during spread, emergence, and evolution of RNA viruses [22]. Hantavirus spillover is more likely to occur with host populations inhabiting sympatric or syntopic regions, and cross-species transmission would presumably have greater chances of success if the host species are closely related [23]. "
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    • "The understanding of viral transmission proves to be far more complex when species other than the main reservoir host are incorporated in the model. In fact, recent studies have shown that higher hosts species diversity is correlated with lower infection prevalence in North America for P. maniculatus [177], in Central America for O. fulvescens (reservoir of Choclo virus) and Zygodontomys brevicauda (reservoir of Calabazo virus) [178], and in South America for Akodon montensis (reservoir of Jabora virus) [162]. Contact rates vary according to the spatial distribution of populations and seem to be strongly influenced by landscape structure. "
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    • "tact, thus facilitating ''hostjumping'' and/or genetic reassortment (Chu et al. 2009; McCormack and Allen 2006, 2007b). As demonstrated by our study, of particular importance will be mathematical models that explicitly incorporate spatial and habitat variability and are capable of investigating these phenomena at multiple spatial scales (Goodin et al. 2006, 2009)."
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