Cost and sensitivity of on-farm versus slaughterhouse surveys for prevalence estimation and substantiating freedom from disease.
Within the framework of Swiss surveillance for epizootic diseases, dairy cattle are sampled using bulk tank milk while non-dairy cattle are sampled on the farm. The latter method is costly, time-demanding and dangerous for the personnel. However, slaughterhouses could be an alternative sampling point for this population. To assess the cost-effectiveness and sensitivity of such an approach, surveillance using slaughterhouse sampling was modelled with data from the 2012 Swiss animal movement database (AMD). We simulated a cross-sectional study for bluetongue (BT), and surveillance programmes to substantiate freedom from infectious bovine rhinotracheitis (IBR) and enzootic bovine leucosis (EBL) (combined) to compare the outcome of random on-farm sampling versus slaughterhouse sampling. We found that, under Swiss conditions, slaughterhouse sampling results in low herd-level sensitivities because animals are sent by owners to slaughter individually and not in large groups, restricting the number of samples per herd. This makes slaughterhouse sampling inappropriate for prevalence surveys at the herd-level. However, for prevalence surveys at the animal-level and for substantiation of freedom from disease, slaughterhouse surveillance is equally or more cost-efficient than on-farm sampling.
Veterinary Public Health Institute, University of Berne, Berne, Switzerland. Electronic address: sara.schaerrer@vetsuisse.unibe.ch.
Sara
S
Schärrer
Food Safety and Veterinary Office, Berne, Switzerland.
Heinzpeter
H
Schwermer
Veterinary Public Health Institute, University of Berne, Berne, Switzerland.
Patrick
P
Presi
National Veterinary Institute, Uppsala, Sweden.
Ann
A
Lindberg
Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland.
Jakob
J
Zinsstag
Food Safety and Veterinary Office, Berne, Switzerland.
Martin
M
Reist
D000003:Abattoirs / Q000191:economics / Q000706:statistics & numerical data; D000818:Animals; D001819:Bluetongue / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000191:economics / Q000453:epidemiology*; D003362:Cost-Benefit Analysis; D003430:Cross-Sectional Studies; D003612:Dairying / Q000191:economics / Q000706:statistics & numerical data; D016583:Enzootic Bovine Leukosis / Q000453:epidemiology; D005260:Female; D007241:Infectious Bovine Rhinotracheitis / Q000453:epidemiology; D008297:Male; D011159:Population Surveillance / Q000379:methods; D015995:Prevalence; D012680:Sensitivity and Specificity; D013557:Switzerland / Q000453:epidemiology
Animal movement database; Cross-sectional study; Simulation; Slaughterhouse surveillance; Substantiate freedom from disease