Research funded by the Swine Health Information Center at North Carolina State University shows it is possible to develop accurate forecasts of porcine epidemic diarrhea virus spread within a decision-making timeframe. Results also show predictability of this forecasting depends on the stage of the spread within the region. By forecasting outbreaks before they occur, specific control strategies can be tailored to farms, thereby offering an opportunity to prevent infection.
The objective of the study was to develop a way to forecast PEDV outbreaks by generating weekly high-resolution maps to track spread and identify current and future PEDV high risk areas. Within the outbreak models, the researchers then tested a combination of strategies that might reduce between-farm transmission, knowing this is key to maintain control of outbreaks while minimizing production disruptions.
Three epidemiological transmission models were compared in this work:
- A novel epidemiological framework called PigSpread developed specifically to model disease movement in swine populations
- SimInf, a program that models disease spread as a more random event
- PoPS (Pest or Pathogen Spread), a framework for modeling the spread of pests or pathogens across a landscape
The models were calibrated on true weekly PEDV outbreaks from three spatially related swine companies within the study region. Model outputs had general agreement with observed outbreaks throughout the study period with some variability between models. The analysis estimates of the combined strategies of herd closure, feedback and reinforcement of on-farm biosecurity reduced the incidence of outbreaks in sow farms by 14% and in gilt development units by 20% when deployed weekly in sow and GDU farms located in risk areas.
As the world deals with the COVID-19 pandemic, SHIC continues to focus efforts on prevention, preparedness and response to novel and emerging swine disease for the benefit of U.S. swine health. SHIC is funded by America's pork producers to fulfill its mission to protect and enhance the health of the U.S. swine herd.