Results of epidemic simulation modeling to evaluate strategies to control an outbreak of foot-and-mouth disease.
OBJECTIVE
To assess estimated effectiveness of control and eradication procedures for foot-and-mouth disease (FMD) in a region of California.


METHODS
2,238 herds and 5 sale yards in Fresno, Kings, andTulare counties of California.


METHODS
A spatial stochastic model was used to simulate hypothetical epidemics of FMD for specified control scenarios that included a baseline eradication strategy mandated by USDA and supplemental control strategies of slaughter or vaccination of all animals within a specified distance of infected herds, slaughter of only high-risk animals identified by use of a model simulation, and expansion of infected and surveillance zones.


RESULTS
Median number of herds affected varied from 1 to 385 (17% of all herds), depending on type of index herd and delay in diagnosis of FMD. Percentage of herds infected decreased from that of the baseline eradication strategy by expanding the designated infected area from 10 to 20 km (48%), vaccinating within a 50-km radius of an infected herd (41%), slaughtering the 10 highest-risk herds for each infected herd (39%), and slaughtering all animals within 5 km of an infected herd (24%).


CONCLUSIONS
Results for the model provided a means of assessing the relative merits of potential strategies for control and eradication of FMD should it enter the US livestock population. For the study region, preemptive slaughter of highest-risk herds and vaccination of all animals within a specified distance of an infected herd consistently decreased size and duration of an epidemic, compared with the baseline eradication strategy.
Bates
Thomas W
TW
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
Thurmond
Mark C
MC
Carpenter
Tim E
TE
D000818:Animals; D002140:California / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000517:prevention & control; D003140:Communicable Disease Control; D003198:Computer Simulation; D004196:Disease Outbreaks / Q000517:prevention & control* / Q000662:veterinary*; D005536:Foot-and-Mouth Disease / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control*; D029544:Foot-and-Mouth Disease Virus / Q000276:immunology; D015511:Goat Diseases / Q000453:epidemiology / Q000517:prevention & control; D006041:Goats; D015994:Incidence; D012757:Sheep Diseases / Q000453:epidemiology / Q000517:prevention & control; D013269:Stochastic Processes; D013553:Swine Diseases / Q000453:epidemiology / Q000517:prevention & control; D014611:Vaccination / Q000662:veterinary; D014765:Viral Vaccines / Q000276:immunology
D014765:Viral Vaccines