title: [The occurrence of hardjo-positive dairy cows in the Northern Netherlands. A prospective serological survey].
abstract: More than 5000 lactating cows from 82 farms, in the northern part of the Netherlands, were serologically examined for antibodies to Leptospira hardjo. Hardjo-positive cows were found on 52% of the farms with a mean incidence of 23% positive animals. Considerable differences were observed in the percentages hardjo-positive cows per region (7-30%), as well as in the percentages positive cows per positive farm (22-46%). With the exception of one region (14%) the percentages of hardjo-positive farms per region hardly differed (average 58%). In addition to the animal survey 488 sera of men working and/or living on cattle-farms were also examined. Twenty-six persons were hardjo-positive. Most of these persons (circa 90%) milked regularly. All seropositive persons were found on farms with hardjo-positive cattle. Results from an inquiry on circa 200 farms indicated, that hardjo-infections probably occur with a higher frequency on larger farms. Finally the results from this survey confirm the observation in the literature, that symptoms of hardjo-infections are more frequently found in the autumn.
authors.affiliation: Afdeling Immunologie, Central Diergeneeskundig Instituut, Lelystad.
authors.forename: B A
authors.initials: BA
authors.lastname: Bokhout
authors.forename: D J
authors.initials: DJ
authors.lastname: Peterse
authors.forename: P L
authors.initials: PL
authors.lastname: Koger
authors.forename: W J
authors.initials: WJ
authors.lastname: Terpstra
mesh_terms: D000372:Agglutination Tests; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D002417:Cattle / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D006801:Humans; D007921:Leptospira interrogans / Q000276:immunology*; D009426:Netherlands; D011159:Population Surveillance; D011446:Prospective Studies
chemical_list: D000907:Antibodies, Bacterial
vernacular_title: Het voorkomen van hardjo-positieve melkrunderen in Noord-Nederland. Een oriënterend serologisch onderzoek.