Source: UNIV OF CALIFORNIA (VET-MED) submitted to NRP
THE VALUE OF ANIMAL MOVEMENT TRACKING: A CASE STUDY SIMULATING THE SPREAD OF FOOT-AND-MOUTH DISEASE (FMD) IN CALIFORNIA
Sponsoring Institution
Cooperating Schools of Veterinary Medicine
Project Status
COMPLETE
Funding Source
Reporting Frequency
Annual
Accession No.
0217138
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Jul 1, 2007
Project End Date
May 25, 2009
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UNIV OF CALIFORNIA (VET-MED)
(N/A)
DAVIS,CA 95616
Performing Department
MEDICINE AND EPIDEMIOLOGY
Non Technical Summary
The California Department of Food and Agriculture (CDFA), the agency responsible for managing statewide animal health programs, is working with the United States Department of Agriculture (USDA) Veterinary Services to implement NAIS in California. As NAIS matures, state agencies like CDFA will assume responsibility for the maintenance of the premises registration system, assis with intrastate movement compliance, and continue to serve as a first line of defense during animal health related incidents. These responsibilities demand that CDFA properly plan and budget for future needs of the Department. Through this project proposal, CDFA will assess the effectiveness of current and NAIS type systems for conducting mock disease traceback and traceforward exercises. Simulated disease outbreaks using models that simulate the FMD transmissions are very informative for animal health officials and scientists. These models provide animal health officials information when actual data are unavailable. The information and experience gained from a simulated disease traceability exercise will address several questions raised by animal health officials, livestock producers, and critics about the effectiveness of the NAIS. Using this information, animal health officials and researchers of contagious disease can improve their efforts to properly plan for major disease outbreaks, assess eradication strategies for a contagious disease and document potential costs associated with these events.
Animal Health Component
40%
Research Effort Categories
Basic
20%
Applied
40%
Developmental
40%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
31133991170100%
Knowledge Area
311 - Animal Diseases;

Subject Of Investigation
3399 - Beef cattle, general/other;

Field Of Science
1170 - Epidemiology;
Goals / Objectives
This project will address the following problems and questions regarding implementation of NAIS: 1) Can the NAIS ID system be used for the purposes of tracebacks and or traceforwards in the face of a Foot-and-Mouth Disease (FMD) outbreak 2) Is the use of the NAIS animal ID system more efficient in the face of a simulated outbreak of FMD than on farm investigations and paper records at identifying potentially infected premises/animals 3) Can the NAIS ID system and paper records be used in an established FMD simulation model to predict potential disease spread and epidemic duration 4) Which data system is more efficient/accurate in helping to predict the outcome of the FMD outbreak as evaluated by the simulation model 5) What are the resource costs of performing tracebacks and traceforwards under both data systems
Project Methods
FIELD EXERCISES: CDFA and UC Davis will conduct field exercises for a mock FMD disease tracing exercise. Using the simulated exercise, investigators will compare and contrast three categories of disease tracing including: an NAIS-type system with full traceability, a paper-based tracing method, and a mixed system of partial NAIS level tracing and on paper-based methods. During the disease exercise, field staff will m onitor resources (personnel, supplies, etc.) needed to conduct the simulated tracing even tusing the three previously mentioned methods. Additionally, they will monitor and record the number of leads and distinguish the number of informative vs. false leads. CDFA will supply UC Davis with the current tracing data from the Southwest Pilot project to assist with the disease tracing exercise and provide a foundation of actual tracing information. CDFA field staff will execute the disease tracing exercises in collaboration with UC Davis by providing staff to conduct the simulated exercise. The plan for the mock disease tracing exercise will be refined closer to the event date. This plan will involve staff from both UC Davis and CDFA and may require modification to meet the objectives of the project. DISEASE SIMULATIONS: CDFA will provide traceback and traceforward finding for each method tested to CADMS and the data will be entered into a simulation model. Using the available data, UC Davis will conduct simulated FMD disease outbreaks. UC Davis will record the duration of the disease event, the number of premises involved, and the number of infected animals. Each tracing method (e.g., NAIS with full traceability vs. paper records) will be run separately for 1,000 iterations. From these iterations, median, mean and 95% probability intervals will be calculated and the results for epidemic duration and spread for each method will be statistically compared.

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: Additions were made to the existing Davis Animal Disease Simulation (DADS) model so that movements of animals can now be traced between two facilities which both participate in a tracing scheme. A survey of experts in animal health with experience in performing disease tracing was performed. PARTICIPANTS: PI managed the project Analyst made changes to the DADS model and assisted with data analysis Analyst collected and analyzed survey data Analyst assisted in coordination of the project and writing of the final report. TARGET AUDIENCES: Results were presented to the California Department of Food and Agriculture, Animal Health Branch (AHB), State Meeting with animal health partners, USDA APHIS VS and the California Animal Health and Food Safety Laboratory (CAHFSL). Results were also presented to USDA animal health workers and other attendees at the USAHA annual meeting in San Diego in October 2009. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Results from this study show that the ability to rapidly trace all animal movements to and from a dairy farm diagnosed with FMD is key to reducing the duration and impact of an epidemic. Alternatively, if paper-based animal movement tracing could be expedited, substantial benefits could be obtained, although they would be less those expected from the proposed electronic system. Results presented here showed that larger premises would require a longer tracing time than smaller premises. Therefore the types of facilities that are infected will impact the speed with which movements can be traced and in turn the relative success at reducing the spread of the epidemic. This knowledge could be used to place an emphasis on larger herds when recruiting farms to participate in the electronic tracing system. Focusing on the larger herds would have a greater impact on reducing disease spread than smaller herds, which would see a smaller benefit, in terms of reduced tracing time, if an electronic tracing system were in place. Perhaps the most interesting finding in this study, relating to length of tracing time, is the importance of expertise on the part of the personnel performing the tracings. Our results show that in general, the most experienced tracers (experts) indicated that time to trace all shipments would be significantly less, than less experienced tracers; however, while the most experienced experts showed some disagreement between their estimates, the estimated minimum tracing times were always shorter than estimates from less experienced tracers, when evaluating alternative herd size and weeks since diagnosis. In general, moderate-level experts' predictions fell between those of the levels the more and less experienced experts. Due to the differences between expert levels it was not possible to create a single-combined probabilistic function to estimate the time to conduct tracings. Thus, mean values for tracing were determined, considering this hierarchical expertise structure. These finding have serious implications in the face of a large disease epidemic, where a large number of personnel would be needed and therefore a greater number of personnel with fewer years of tracing experience would be utilized. Based on model output, a 30-35% reduction in numbers of infected herds was expected if one-day's worth of animal shipments from an infected premises could be traced in a single 8 hour day. This would result in an average reduction of 232 and 383 infected herds for outbreaks starting in large and small dairies, respectively. The findings from this study were presented at the The California Department of Food and Agriculture, Animal Health Branch (AHB), State Meeting with their animal health partners, USDA APHIS VS and the California Animal Health and Food Safety Laboratory (CAHFSL). Results were also presented at the USAHA annual meeting in October 2009 in San Diego.

Publications

  • No publications reported this period


Progress 07/01/07 to 05/25/09

Outputs
OUTPUTS: This project terminated prior to this reporting period and as such there is nothing to report. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
This project terminated prior to this reporting period and as such there is nothing to report.

Publications

  • No publications reported this period