Risk factors for the reinfection of specific pathogen-free pig breeding herds with enzootic pneumonia
Stärk, K.D.; Keller, H.; Eggenberger, E.
Veterinary Record 131(23): 532-535
1992
ISSN/ISBN: 0042-4900 PMID: 1475897 Document Number: 388158
A case control study was designed to determine the risk factors for the reinfection of Swiss specific pathogen-free (SPF) pig herds with enzootic pneumonia. Detailed housing, management and environmental data were collected from 42 case farms and 50 control farms by questionnaire. Factors with a significantly asymmetrical frequency distribution among the 2 groups were considered to be possibly associated with reinfection; they included the distance to the nearest non-SPF pig herd, the size of that herd, the density of the pig population in the area, the distance to the next road regularly carrying pig transporters and differences in topography. The results tended to support the hypothesis of the airborne transmission of enzootic pneumonia. Using a formula considering the main risk factors, it was possible to classify farms as high or low risk with an 84% specificity and 74% sensitivity.