The primary objective of this study was to evaluate risk\u00a0factors for incidence cases of reported PCVAD.\u00a0A time-matched case-control study was used as a study design approach, and conditional logistic\u00a0regression as the analytical method. Briefly, 278 herds located in southern Ontario were\u00a0included in this study initially using two different sampling\u00a0mechanisms: (i) sampling of herds positive for porcine\u00a0reproductive and respiratory syndrome virus\u00a0(PRRSv) using data from a diagnostic laboratory (Animal\u00a0Health Laboratory, University of Guelph, Guelph, ON,\u00a0Canada), based on rtPCR-positive diagnostic findings,\u00a0and (ii) sampling of PRRSv-negative herds, based on\u00a0assessment of a herd veterinarian. Herds were classified\u00a0into PCVAD-positive and negative herds on the basis of\u00a0producers\u2019 assessments, and results obtained during\u00a0exploratory spatial analysis were used to guide the\u00a0design of this case-control study.\u00a0In conclusion, the spread of PCVAD due to high-risk\u00a0local exposure was primarily driven by herd ownership.\u00a0It was therefore impossible to distinguish local spread\u00a0from common direct or indirect sources that contributed\u00a0to the emergence of disease concurrently in different\u00a0premises under the same ownership. Surprisingly, frequency\u00a0of direct or indirect contacts did not differ\u00a0between case and control herds. This also applies to frequency\u00a0of feed delivery, which, although statistically significant,\u00a0was driven by a single highly influential point,\u00a0which in itself did not align with a biological rationale\u00a0for spread through feed deliveries. Two risk factors that\u00a0remained stable were herd PRRSv status and directional\u00a0spread in a western direction.<\/p>\n","protected":false},"excerpt":{"rendered":"
The primary objective of this study was to evaluate risk\u00a0factors for incidence cases of reported PCVAD.\u00a0A time-matched case-control study was used as a study design approach, and conditional logistic\u00a0regression as the analytical method. Briefly, 278 herds located in southern Ontario were\u00a0included in this study initially using two different sampling\u00a0mechanisms: (i) sampling of herds positive for […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[18120,19],"tags":[640,46,7816,4181,35],"class_list":["post-15016","post","type-post","status-publish","format-standard","hentry","category-ontario-pork","category-pork-insight-articles","tag-animal","tag-feed","tag-pcv","tag-prrs","tag-swine"],"_links":{"self":[{"href":"https:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/15016","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/comments?post=15016"}],"version-history":[{"count":1,"href":"https:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/15016\/revisions"}],"predecessor-version":[{"id":15018,"href":"https:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/15016\/revisions\/15018"}],"wp:attachment":[{"href":"https:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/media?parent=15016"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/categories?post=15016"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/tags?post=15016"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}