• Model predicts cross-species contaminati

    From ScienceDaily@1:317/3 to All on Monday, March 14, 2022 22:30:40
    Model predicts cross-species contamination risk for livestock

    Date:
    March 14, 2022
    Source:
    North Carolina State University
    Summary:
    Biosecurity efforts focused on the top 3% of farms in a particular
    contact network may significantly cut back cross-species disease
    dissemination.



    FULL STORY ==========================================================================
    A new mathematical model from researchers at North Carolina State
    University reveals the high risk of cross-species disease spread on farms
    with more than one type of livestock. According to the model, biosecurity efforts focused on the top 3% of farms in a particular contact network
    may significantly cut back cross-species disease dissemination.


    ========================================================================== "Most disease-prevention programs focus control and prevention measures
    on one species; however, it is well known that cross-species transmissions occur," says Gustavo Machado, assistant professor of population health and pathobiology at NC State and corresponding author of a paper describing
    the work. "For example, foot-and-mouth disease can be transmitted among
    all ungulate species.

    And all of these farms are connected -- they sell and share animals all
    the time." Machado and postdoctoral researcher Nicolas Cardenas created
    a stochastic mathematical model that described the "connectedness" of
    farms in one area of Southern Brazil. The model included three years'
    worth of data for a population of 90 million animals and traced over
    1.6 million animal movements between farms, such as animal sales and grow-finishing movements.

    The model simulated disease outbreaks that began in cattle, swine,
    and small ruminants (i.e., sheep or goats), respectively, in order to
    determine the likelihood of cross-species contamination in each case. They
    ran 1,000 distinct simulations 100 times each to identify all possible
    outbreak routes.

    "It doesn't matter where the outbreak starts, the entire farm -- and the
    larger farm network in a community -- is at risk," Cardenas says. "We
    ran simulations with diseases that are transmitted by direct contact,
    and modeled outbreaks that started on both single-species and multi-host
    farms to see if there was a difference in outcome, and there wasn't."
    However, Cardenas says, knowing how farms interact with each other and
    focusing biosecurity and prevention efforts on the most interconnected
    farms does have an impact.

    "The model allowed us to construct a contact network between all of
    the farms in the study," Cardenas says. "The farms with the greatest
    numbers of contacts, or hub farms -- regardless of how many animals
    move between them -- are the focal points for disease transmission."
    The researchers found that identifying the top 3% of hub farms and
    focusing biosecurity efforts there dramatically reduced the number of secondarily infected farms.

    "The model shows us a number of interesting points," Machado says. "First,
    it shows us that we cannot look only at the immediately affected species
    during an outbreak, as all of the animals are at risk. Second, if you
    target biosecurity efforts toward the top ~3% of the most networked
    farms you can reduce transmission on those farms and protect other
    species as well.

    "We hope that this model can help public health officials and
    farmers target disease counteraction efforts more efficiently and cost-effectively." The work appears in Veterinary Research and was
    supported by the Fundo de Desenvolvimento e Defesa Sanita'ria Animal (FUNDESA-RS) under award number 2021-1318.


    ========================================================================== Story Source: Materials provided by
    North_Carolina_State_University. Original written by Tracey Peake. Note: Content may be edited for style and length.


    ========================================================================== Journal Reference:
    1. Nicolas C. Cardenas, Abagael L. Sykes, Francisco P. N. Lopes,
    Gustavo
    Machado. Multiple species animal movements: network
    properties, disease dynamics and the impact of targeted
    control actions. Veterinary Research, 2022; 53 (1) DOI:
    10.1186/s13567-022-01031-2 ==========================================================================

    Link to news story: https://www.sciencedaily.com/releases/2022/03/220314154413.htm

    --- up 2 weeks, 10 hours, 50 minutes
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)