{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,23]],"date-time":"2026-01-23T10:51:50Z","timestamp":1769165510109,"version":"3.49.0"},"reference-count":30,"publisher":"Cambridge University Press (CUP)","issue":"3","license":[{"start":{"date-parts":[[2009,4,6]],"date-time":"2009-04-06T00:00:00Z","timestamp":1238976000000},"content-version":"unspecified","delay-in-days":8345,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Parasitology"],"published-print":{"date-parts":[[1986,6]]},"abstract":"<jats:title>SUMMARY<\/jats:title><jats:p>The numerical distributions of <jats:italic>Echinococcus granulosus<\/jats:italic> in an experimental dog population are described. At all dose rates of protoscoleces from 10 to 175000 the distribution of worms was over-dispersed. Host age had no effect. There was a direct proportionality between the infective-stage density and rate of infection, and between the latter and the index of clumping. The worm burdens were significantly higher in the proximal than distal portions of the small intestine. Lengths of the 3- and 4-segmented worms increased from 4 to 10 and 4 to 8 weeks of age, respectively. Thereafter apolysis was asynchronous and could not be determined. Eggs were first detected in the faeces at 6 weeks and the mean age at oogenesis was 7\u00b726 weeks. Retarded growth of the whole population of worms was observed in some dogs. For the first few infections, worm burdens varied widely in the same dog, but by the 6th infection 50% of the dog population had developed a relative insusceptibility to infection. Growth or oogenesis of the worms were not affected. A short-acting immune response was artificially induced in some dogs following the parenteral injection of activated embryos of <jats:italic>E. granulosus, Taenia hydatigena, T. ovis, T. multiceps, T. pisiformis<\/jats:italic> and <jats:italic>T. serialis<\/jats:italic>. The response affected either the number of worms established, growth or oogenesis or all three parameters. There was a strong positive correlation between numbers and lengths of worms in dogs with acquired and induced immunity, indicating that no \u2018crowding\u2019 effects were involved. In sheep populations the mean number of cysts which established was directly proportional to the number of eggs given, implying that there was no negative feedback mechanism operating at this stage of the life-cycle. The distribution of the larval population in sheep was over-dispersed and the index of clumping increased with the size of the egg dose from 25 to 2500 eggs. Protoscoleces were first observed in cysts at 2 years and the proportion producing them increased with age, with an estimate of 50% of cysts containing protoscoleces at 6 years. No deaths were observed in dogs or sheep even when high parasite burdens were present, implying that <jats:italic>E. granulosus<\/jats:italic> does not regulate the population of its hosts.<\/jats:p>","DOI":"10.1017\/s0031182000065483","type":"journal-article","created":{"date-parts":[[2009,6,5]],"date-time":"2009-06-05T16:20:46Z","timestamp":1244218846000},"page":"599-620","source":"Crossref","is-referenced-by-count":97,"title":["Population dynamics in echinococcosis and cysticercosis: biological parameters of <i>Echinococcus granulosus<\/i> in dogs and sheep"],"prefix":"10.1017","volume":"92","author":[{"given":"M. A.","family":"Gemmell","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"J. R.","family":"Lawson","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M. G.","family":"Roberts","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"56","published-online":{"date-parts":[[2009,4,6]]},"reference":[{"key":"S0031182000065483_ref026","volume-title":"The Physiology of Cestodes","author":"Smyth","year":"1969"},{"key":"S0031182000065483_ref020","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182000052847"},{"key":"S0031182000065483_ref017","doi-asserted-by":"publisher","DOI":"10.1016\/0014-4894(77)90104-7"},{"key":"S0031182000065483_ref008","doi-asserted-by":"publisher","DOI":"10.1016\/0035-9203(72)90083-1"},{"key":"S0031182000065483_ref024","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182000065495"},{"key":"S0031182000065483_ref007","doi-asserted-by":"publisher","DOI":"10.2307\/3677"},{"key":"S0031182000065483_ref030","volume-title":"Immunology of Parasitic Infections","author":"Williams","year":"1982"},{"key":"S0031182000065483_ref022","doi-asserted-by":"publisher","DOI":"10.2307\/3934"},{"key":"S0031182000065483_ref018","doi-asserted-by":"publisher","DOI":"10.1016\/S0065-308X(08)60531-X"},{"key":"S0031182000065483_ref028","volume-title":"Ecological Methods","author":"Southwood","year":"1978"},{"key":"S0031182000065483_ref001","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182000049398"},{"key":"S0031182000065483_ref009","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182000071420"},{"key":"S0031182000065483_ref003","first-page":"303","volume-title":"Parasites\u2013Their World and Ours","author":"Anderson","year":"1982"},{"key":"S0031182000065483_ref010","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182000079890"},{"key":"S0031182000065483_ref004","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182000055347"},{"key":"S0031182000065483_ref005","doi-asserted-by":"publisher","DOI":"10.2307\/3933"},{"key":"S0031182000065483_ref006","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182000049386"},{"key":"S0031182000065483_ref011","doi-asserted-by":"publisher","DOI":"10.1111\/j.1751-0813.1952.tb13436.x"},{"key":"S0031182000065483_ref012","first-page":"495","article-title":"Natural and acquired immunity factors interfering with development during the rapid growth phase of Echinococcus granulosus in dogs","volume":"5","author":"Gemmell","year":"1962","journal-title":"Immunology"},{"key":"S0031182000065483_ref014","first-page":"57","article-title":"Screening of drugs and their assessment for use against the strobilate phase of Echinococcus","volume":"39","author":"Gemmell","year":"1968","journal-title":"Bulletin of the World Health Organization"},{"key":"S0031182000065483_ref015","first-page":"122","article-title":"Safe handling of infected definitive hosts and eggs of Echinococcus spp","volume":"39","author":"Gemmell","year":"1968","journal-title":"Bulletin of the World Health Organization"},{"key":"S0031182000065483_ref016","first-page":"333","volume-title":"Immunology of Human Parasite infections","author":"Gemmell","year":"1976"},{"key":"S0031182000065483_ref019","doi-asserted-by":"publisher","DOI":"10.1016\/0020-7519(77)90081-9"},{"key":"S0031182000065483_ref021","first-page":"646","article-title":"Invasionsversuchedurch Scolices Echinococcus granulosus bei Hunden","volume":"28","author":"L\u00fcbke","year":"1973","journal-title":"Tier\u00e4rztliche Umschau"},{"key":"S0031182000065483_ref025","volume-title":"Minitab Reference Manual","author":"Ryan","year":"1982"},{"key":"S0031182000065483_ref027","volume-title":"Statistical Methods","author":"Snedecor","year":"1980"},{"key":"S0031182000065483_ref029","doi-asserted-by":"publisher","DOI":"10.2307\/3280271"},{"key":"S0031182000065483_ref013","first-page":"325","article-title":"Immunological responses of the mammalian host against tapeworm infections. 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Species specificity of hexacanth embryos against Echinococcus granulosus","volume":"11","author":"Gemmell","year":"1966","journal-title":"Immunology"},{"key":"S0031182000065483_ref023","volume-title":"The Biology of Cestodes","author":"Rickard","year":"1983"},{"key":"S0031182000065483_ref002","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182000047739"}],"container-title":["Parasitology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0031182000065483","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,5,22]],"date-time":"2019-05-22T05:53:22Z","timestamp":1558504402000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S0031182000065483\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1986,6]]},"references-count":30,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1986,6]]}},"alternative-id":["S0031182000065483"],"URL":"https:\/\/doi.org\/10.1017\/s0031182000065483","relation":{},"ISSN":["0031-1820","1469-8161"],"issn-type":[{"value":"0031-1820","type":"print"},{"value":"1469-8161","type":"electronic"}],"subject":[],"published":{"date-parts":[[1986,6]]}}}