Occurrence of respiratory disease outbreaks in fattening pigs: Relation with the features of a densely and a sparsely populated pig area in France

Abstract

-A survey was carried out in France in 1999 in a Densely Populated Pig Area (DPPA) and a Sparsely Populated Pig Area (SPPA) from which 80 and 55 pig farms were respectively investigated. The two areas were compared regarding the number of respiratory disease outbreaks in fattening pigs on each farm per year with a multiple correspondence analysis and hierarchical clustering. The two areas exhibited different typologies: in the DPPA, high density was associated with a high proportion of finishing-pig units resulting in much moving of piglets within the area. Farrow-to-finish farms located in the DPPA had many contacts with external vehicles; this was associated with more than two respiratory disease outbreaks per farm per year. There also was a lack of biosecurity measures implemented on these farms. Conversely, the good health situation of the farms located in the SPPA was associated with few external contacts and good biosecurity measures. In a second step, risk factors for the occurrence of more than 2 respiratory outbreaks per year were studied. Having more than 4 pig farms within a 2 km radius area, more than 30 incoming rendering trucks per year, and storage of the carcasses of dead animals within the farmyard perimeter increased the risk of occurrence of more than 2 respiratory disease outbreaks per year on the farm. This risk was also increased when there were more than 2 animal-transport lorries entering the farm per month and more than 1 veterinarian's or technician's vehicle coming in every 2 months. These results were discussed because of possible bias due to the retrospective design of the survey and the sampling scheme (randomisation within two areas). (33) 296 016 253; e-mail: n.rose@ploufragan.afssa.fr des élevages (nombre d'épisodes de type grippal en engraissement) au moyen d'une analyse factorielle des correspondances multiples suivie d'une classification ascendante hiérarchique. Les deux zones présentaient une typologie différente : en zone FD, la forte densité était associée à un nombre d'élevages plus important de type engraisseur, impliquant une circulation des porcelets plus importante. La forte fréquentation des élevages naisseur-engraisseurs situés dans cette zone par les véhicu-les extérieurs, peut être interprétée en tant que cause ou conséquence d'une situation sanitaire difficile (nombre de syndromes grippaux en engraissement > 2 par an), exacerbée par le manque de précau-tions sanitaires prises par ces mêmes élevages. En zone BD, la bonne situation sanitaire des élevages à l'égard de la pathologie cible, était associée à une faible fréquentation par les véhicules extérieurs et à la mise en place de mesures de biosécurité. Dans un second temps, les facteurs de risque de l'expression clinique de plus de 2 syndromes grippaux par an ont été recherchés. Le modèle de régression logistique a permis de mettre en évidence que la densité d

Occurrence and spread of influenza A(H1N1)pdm09 virus infection in Norwegian pig herds based on active serosurveillance from 2010 to 2014

“…Higher density pig-farming counties also mean larger quantities of virus shed into the environment which increases the probability of transmission to susceptible hosts. Other studies have also shown that higher pig-density areas also have higher rates of respiratory diseases [36, 37]. …”

Prevalence and risk factors for swine influenza virus infection in the English pig population

“…Although this approach was based on an understanding of English pig herds and the dynamics of disease within these, it is subjective in nature, and therefore could result in bias. Other statistical techniques which could have been used for the identification of different pig herd types include scoring systems [36], multiple correspondence analysis [37], multiple factor analysis and hierarchal cluster analysis [38] [39], and multiblock redundancy analysis. These approaches were not used here as the presence of missing data for some of the variables would have led to the exclusion of a substantial number of farms.…”

Evaluation of suitable reference genes for gene expression studies in porcine alveolar macrophages in response to LPS and LTA

“…Swine respiratory diseases, which has been described world-wide, affects swine of all ages and has a serious impact on economy, ecology and animal welfare in the pig rearing industry [2]. Both Gram-positive and Gram-negative bacteria are causing respiratory disease in pigs [3].…”