Simulation study of the mechanisms underlying outbreaks of clinical disease caused by Actinobacillus pleuropneumoniae in finishing pigs
Autor: | Klinkenberg, D, Tobias, T J, Bouma, A, van Leengoed, L A M G, Stegeman, J A, FAH SIB, Sub GZ Varken/Pluimvee, LS GZ Landbouwhuisdieren, Sub Junior Docenten, Strategic Infection Biology |
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Přispěvatelé: | FAH SIB, Sub GZ Varken/Pluimvee, LS GZ Landbouwhuisdieren, Sub Junior Docenten, Strategic Infection Biology |
Jazyk: | angličtina |
Rok vydání: | 2014 |
Předmět: |
Swine
Disease Models Biological Disease Outbreaks Actinobacillus Infections Mathematical model medicine Animals Transmission Computer Simulation Actinobacillus pleuropneumoniae Swine Diseases General Veterinary biology Transmission (medicine) Mechanism (biology) Prevention Outbreak Clinical disease medicine.disease biology.organism_classification Virology Pleuropneumonia Animal Science and Zoology Pneumonia (non-human) |
Zdroj: | Veterinary Journal, 202(1), 99. Bailliere Tindall Ltd |
ISSN: | 1532-2971 |
Popis: | Actinobacillus pleuropneumoniae is a major cause of respiratory disease in pigs. Many farms are endemically infected without apparent disease, but occasionally severe outbreaks of pleuropneumonia occur. To prevent and control these outbreaks without antibiotics, the underlying mechanisms of these outbreaks need to be understood. Outbreaks are probably initiated by a trigger (common risk factor) changing the host-pathogen interaction, but it is unclear whether this trigger causes all cases directly (trigger mechanism), or whether the first case starts a transmission chain inducing disease in the infected contacts (transmission mechanism). The aim of this study was to identify conditions under which these mechanisms could cause A. pleuropneumoniae outbreaks, and to assess means for prevention and control. Outbreaks were first characterised by data from a literature review, defining an average outbreak at 12 weeks of age, affecting 50% of animals within 4 days. Simple mathematical models describing the two mechanisms can reproduce average outbreaks, with two observations supporting the trigger mechanism: (1) disease should be transmitted 50 times faster than supported by literature if there is a transmission chain; and (2) the trigger mechanism is consistent with the absence of reported outbreaks in young pigs as they have not yet been colonised by the bacterium. In conclusion, outbreaks of A. pleuropneumoniae on endemic farms are most likely caused by a trigger inducing pneumonia in already infected pigs, but more evidence is needed to identify optimum preventive interventions. |
Databáze: | OpenAIRE |
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