A Meta-Population Model of Potential Foot-and-Mouth Disease Transmission, Clinical Manifestation, and Detection Within U.S. Beef Feedlots
Open Access
- 23 September 2020
- journal article
- research article
- Published by Frontiers Media SA in Frontiers in Veterinary Science
- Vol. 7, 527558
- https://doi.org/10.3389/fvets.2020.527558
Abstract
Foot-and-mouth disease (FMD) has not been reported in the U.S. since 1929. Recent outbreaks in previously FMD-free countries raise concerns about potential FMD introductions in the U.S. Mathematical modeling is the only tool for simulating infectious disease outbreaks in non-endemic territories. In the majority of prior studies, FMD virus (FMDv) transmission on-farm was modeled assuming homogenous animal mixing. This assumption is implausible for U.S. beef feedlots which are divided into multiple home-pens without contact between home-pens except fence line with contiguous home-pens and limited mixing in hospital pens. To project FMDv transmission and clinical manifestation in a feedlot, we developed a meta-population stochastic model reflecting the contact structure. Within a home-pen, the dynamics were represented assuming homogenous animal mixing by a modified SLIR (susceptible-latent-infectious-recovered) model with four additional compartments tracing cattle with subclinical or clinical FMD and infectious status. Virus transmission among home-pens occurred via cattle mixing in hospital-pen(s), cowboy pen rider movements between home-pens, airborne, and for contiguous home-pens fence-line and via shared water-troughs. We modeled feedlots with a one-time capacity of 4,000 (small), 12,000 (medium), and 24,000 (large) cattle. Common cattle demographics, feedlot layout, endemic infectious and non-infectious disease occurrence, and production management were reflected. Projected FMD-outbreak duration on a feedlot ranged from 49 to 82 days. Outbreak peak day (with maximum number of FMD clinical cattle) ranged from 24 (small) to 49 (large feedlot). Detection day was 4–12 post-FMD-introduction with projected 28, 9, or 4% of cattle already infected in a small, medium, or large feedlot, respectively. Depletion of susceptible cattle in a feedlot occurred by day 23–51 post-FMD-introduction. Parameter-value sensitivity analyses were performed for model outputs. Detection occurred sooner if there was a higher initial proportion of latent animals in the index home-pen. Shorter outbreaks were associated with a shorter latent period and higher bovine respiratory disease morbidity (impacting the in-hospital-pen cattle mixing occurrence). This first model of potential FMD dynamics on U.S. beef feedlots shows the importance of capturing within-feedlot cattle contact structure for projecting infectious disease dynamics. Our model provides a tool for evaluating FMD outbreak control strategies.Keywords
This publication has 63 references indexed in Scilit:
- Estimation of the Infection Window for the 2010/2011 Korean Foot-and-Mouth Disease OutbreakOsong Public Health and Research Perspectives, 2013
- Epidemiology of the Foot-and-Mouth Disease Serotype O Epidemic of November 2010 to April 2011 in the Republic Of KoreaTransboundary and Emerging Diseases, 2013
- Associations between the distance traveled from sale barns to commercial feedlots in the United States and overall performance, risk of respiratory disease, and cumulative mortality in feeder cattle during 1997 to 20091Journal of Animal Science, 2012
- Modeling the spread and control of foot-and-mouth disease in Pennsylvania following its discovery and options for controlPreventive Veterinary Medicine, 2012
- Associations between weather conditions during the first 45 days after feedlot arrival and daily respiratory disease risks in autumn-placed feeder cattle in the United States1Journal of Animal Science, 2012
- Parameterization of the duration of infection stages of serotype O foot-and-mouth disease virus: an analytical review and meta-analysis with application to simulation modelsVeterinary Research, 2010
- Transmission risks and control of foot-and-mouth disease in The Netherlands: Spatial patternsEpidemics, 2010
- Modelling foot and mouth diseasePreventive Veterinary Medicine, 2009
- Modelling vaccination strategies against foot-and-mouth diseaseNature, 2002
- Spatial Heterogeneity in Epidemic ModelsJournal of Theoretical Biology, 1996