{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T00:34:26Z","timestamp":1792024466775,"version":"4.4.0"},"reference-count":0,"publisher":"Cambridge University Press (CUP)","issue":"5","license":[{"start":{"date-parts":[[1999,11,1]],"date-time":"1999-11-01T00:00:00Z","timestamp":941414400000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Parasitology"],"published-print":{"date-parts":[[1999,11]]},"abstract":"<jats:p>In Denmark, Finland, Iceland, Norway and Sweden, 413 sow herds were randomly selected for sampling. Faeces from \npigs of 7 age groups\/categories were examined for helminth eggs (11233 individual samples), and an accompanying \nquestionnaire was completed at each visit. In total, 1138 pigs on 230 farms were found to be positive for <jats:italic>Ascaris suum<\/jats:italic>. \nConsiderable differences in the occurrence of <jats:italic>A. suum<\/jats:italic> could be observed directly for several of 20 independent variables \nat the herd or category level. However, given that univariate analyses may be severely affected by confounding of covariates \nresulting in spurious inference, additional multivariate analyses were undertaken. An ordinary logistic regression on \n<jats:italic>Ascaris<\/jats:italic> positive\/negative farms showed that Denmark had the highest frequency of infected herds, while Iceland and \nFinland had the lowest frequencies and that herds using \u2018late weaning\u2019 and \u2018Class 2\u2019 drugs (pyrantel, levamisole) were most \noften infected. Because many herds were found to be totally negative for <jats:italic>A. suum<\/jats:italic>, mixed hierarchical logistic-normal \nregression models (both the penalized quasi-likelihood and the Markov Chain Monte Carlo methods) were developed for \nboth a full (all herds) and a reduced (the 230 infected herds) data set using either a cut-off of &gt;0 eggs per gram (epg) or \n&gt;200 epg to counter for false-positive egg counts. Estimates for identical models, but where the animal level variance was \nconstrained to the binomial assumption, were also calculated. Significant covariates were robust to model development \nwith \u2018Age group\u2019, \u2018Country\u2019, \u2018Weaning age\u2019, \u2018Water system\u2019 and simple interactions between the latter two and \u2018Age \ngroup\u2019 being significantly associated with the occurrence of <jats:italic>A. suum<\/jats:italic>, while all variables concerning anthelmintic drug, \nanthelmintic strategy, floor type, bedding, dung removal, washing and disinfection were not. These findings are discussed \nin the light of the complex relationship between <jats:italic>A. suum<\/jats:italic> and its pig host.<\/jats:p>","DOI":"10.1017\/s0031182099004941","type":"journal-article","created":{"date-parts":[[2002,7,27]],"date-time":"2002-07-27T09:30:22Z","timestamp":1027762222000},"page":"521-534","source":"Crossref","is-referenced-by-count":27,"title":["Intestinal parasites in swine in the Nordic countries: \nmultilevel modelling of <i>Ascaris suum<\/i> infections in relation \nto production factors"],"prefix":"10.1017","volume":"119","author":[{"given":"A.","family":"ROEPSTORFF","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"O.","family":"NILSSON","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C. J.","family":"O'CALLAGHAN","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"OKSANEN","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"B.","family":"GJERDE","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S. H.","family":"RICHTER","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"E. \u00d6.","family":"ORTENBERG","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D.","family":"CHRISTENSSON","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P.","family":"NANSEN","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L.","family":"ERIKSEN","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"G. F.","family":"MEDLEY","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"56","published-online":{"date-parts":[[1999,11,1]]},"container-title":["Parasitology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0031182099004941","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,5,9]],"date-time":"2019-05-09T15:58:57Z","timestamp":1557417537000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S0031182099004941\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1999,11]]},"references-count":0,"journal-issue":{"issue":"5","published-print":{"date-parts":[[1999,11]]}},"alternative-id":["S0031182099004941"],"URL":"https:\/\/doi.org\/10.1017\/s0031182099004941","relation":{},"ISSN":["0031-1820","1469-8161"],"issn-type":[{"value":"0031-1820","type":"print"},{"value":"1469-8161","type":"electronic"}],"subject":[],"published":{"date-parts":[[1999,11]]}}}