|Ayala, Andrea - University Of Georgia|
|Hamal, Krishna - Us Food & Drug Administration (FDA)|
|Diel, Diego - South Dakota State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/28/2015
Publication Date: N/A
Technical Abstract: As emerging and persistent pathogens increase in prevalence, the agriculture-wildlife interface has been identified as a field requiring further research. Acceleration of wildlife urbanization, exotic species introductions, and habitat encroachment are disrupting barriers that once separated microbes from atypical hosts. The disintegration of the host-pathogen barriers allow rapidly-evolving microbes crucial pathways to opportunistically invade and persist in novel hosts. These “spillover events,” from which pathogens expand their range of susceptible species may irrupt into epidemics with regional or population-level consequences; for example, West Nile virus in the U.S. One pathogen exhibiting fluctuating epizootics at the agricultural-wildlife intersection is Newcastle disease virus (NDV); an RNA virus representing at least 18 genotypes with numerous isolates of varying pathogenicity. A wide body of literature attests to a diverse host range including free-ranging birds and poultry species, although primarily distinguished as a poultry disease agent. Laboratory studies in conjunction with surveillance data identified hundreds of wild bird species with the potential to seroconvert and/or shed NDV to birds of the same species or even among mixed-species flocks. Agricultural operations represent a unique habitat for NDV and peridomestic birds, including commonly found House Sparrows (HOSPs), which quickly adapted to foraging and roosting in accessible sites around human made structures, including poultry houses. Serology from poultry farms and experimental data on viral shedding determined that HOSPs are not only susceptible to NDV, but may transmit the virus to other sparrows, leading to the possibility that HOSPs may serve as NDV ‘reservoirs’ to poultry. To address the potential of bi-directionality of HOSPs NDV transmittal to poultry, we present a modified SEIR (Susceptible-Exposed-Infectious-Recovered) model incorporating behavior, environmental contamination, and waning immunity as covariates of disease risk. Numerical parameters such as HOSPs and poultry density, contact rates, and vaccine spillover to HOSPs resulting in poultry transmission disruption will undergo simulations varying the constants for these parameters. Ultimately, the primary objective is to assess the utility of NDV vaccination and of biosecurity measures by identifying the optimal interaction of these two intervention strategies in the event of an ND outbreak.