Methodological approach for substantiating disease freedom in a heterogeneous small population. Application to ovine scrapie, a disease with a strong genetic susceptibility

Autor: Didier Calavas, Christian Ducrot, Marie-José Martinez, Benoit Durand
Přispěvatelé: Unité de recherche d'Épidémiologie Animale (UEA), Institut National de la Recherche Agronomique (INRA), Modelling and Inference of Complex and Structured Stochastic Systems (MISTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut National Polytechnique de Grenoble (INPG), Laboratoire de Lyon, Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES), Unité de Recherche d'Épidémiologie Animale (UR EpiA), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Lyon [ANSES], Université de Lyon-Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES)
Jazyk: angličtina
Rok vydání: 2010
Předmět:
Male
040301 veterinary sciences
MESH: Probability
Population
MESH: Sheep
Scrapie
Biology
MESH: Risk Assessment
Risk Assessment
Statistical power
0403 veterinary science
POPULATION HETEROGENEITY
03 medical and health sciences
DISEASE FREEDOM
Food Animals
HYPERGEOMETRIC DISTRIBUTION
Statistics
Prevalence
Genetic predisposition
Animals
Genetic Predisposition to Disease
MESH: Animals
education
MESH: Prevalence
Probability
030304 developmental biology
0303 health sciences
education.field_of_study
Sheep
[SDV.BA.MVSA]Life Sciences [q-bio]/Animal biology/Veterinary medicine and animal Health
MESH: Genetic Predisposition to Disease
Sampling (statistics)
04 agricultural and veterinary sciences
Confidence interval
Hypergeometric distribution
MESH: Male
Relative risk
MESH: Scrapie
MESH: Sentinel Surveillance
Female
Animal Science and Zoology
[SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie
Sentinel Surveillance
MESH: Female
[STAT.ME]Statistics [stat]/Methodology [stat.ME]
Zdroj: Preventive Veterinary Medicine
Preventive Veterinary Medicine, Elsevier, 2010, 95 (1-2), pp.108-114. ⟨10.1016/j.prevetmed.2010.02.017⟩
Preventive Veterinary Medicine, 2010, 95 (1-2), pp.108-114. ⟨10.1016/j.prevetmed.2010.02.017⟩
ISSN: 0167-5877
DOI: 10.1016/j.prevetmed.2010.02.017⟩
Popis: International audience; Demonstrating disease freedom is becoming important in different fields including animal disease control. Most methods consider sampling only from a homogeneous population in which each animal has the same probability of becoming infected. In this paper, we propose a new methodology to calculate the probability of detecting the disease if it is present in a heterogeneous population of small size with potentially different risk groups, differences in risk being defined using relative risks. To calculate this probability, for each possible arrangement of the infected animals in the different groups, the probability that all the animals tested are test-negative given this arrangement is multiplied by the probability that this arrangement occurs. The probability formula is developed using the assumption of a perfect test and hypergeometric sampling for finite small size populations. The methodology is applied to scrapie, a disease affecting small ruminants and characterized in sheep by a strong genetic susceptibility defining different risk groups. It illustrates that the genotypes of the tested animals influence heavily the confidence level of detecting scrapie. The results present the statistical power for substantiating disease freedom in a small heterogeneous population as a function of the design prevalence, the structure of the sample tested, the structure of the herd and the associated relative risks.
Databáze: OpenAIRE