title: Increased risk of abortion following Neospora caninum abortion outbreaks: a retrospective and prospective cohort study in four dairy herds.
abstract: Explosive abortion outbreaks in 4 Dutch dairy herds during 1992 to 1994 are reported. In 50 of 51 fetuses submitted during the first 3 wk of the outbreaks characteristic histological lesions compatible for infection with Neospora caninum were seen. Diagnosis of infection was confirmed by immunohistochemistry in 40 fetuses (78%). No evidence for other abortifacients was found. The abortion risk of the herds was investigated in a prospective and retrospective cohort study. The prospective study showed that cows aborting during the outbreaks and N. caninum seropositive nonaborting cows had a two- to three-fold increased risk of abortion compared with N. caninum seronegative cows. Retrospective examination showed that seropositive nonaborting cows had an increased risk of abortion before the outbreaks, which may indicate that these animals were infected with N. caninum prior to the outbreaks. It is concluded that serostatus can be used for selective culling of cows to decrease future risk of abortion in dairy herds.
authors.affiliation: Institute of Animal Science, Wageningen Agricultural University, The Netherlands.
authors.forename: A R
authors.initials: AR
authors.lastname: Moen
authors.forename: W
authors.initials: W
authors.lastname: Wouda
authors.forename: M F
authors.initials: MF
authors.lastname: Mul
authors.forename: E A
authors.initials: EA
authors.lastname: Graat
authors.forename: T
authors.initials: T
authors.lastname: van Werven
mesh_terms: D000034:Abortion, Veterinary / Q000453:epidemiology* / Q000469:parasitology; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000469:parasitology; D003048:Coccidiosis / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D015331:Cohort Studies; D004196:Disease Outbreaks / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D007150:Immunohistochemistry; D016015:Logistic Models; D018688:Neospora / Q000472:pathogenicity*; D009426:Netherlands / Q000453:epidemiology; D011247:Pregnancy; D011446:Prospective Studies; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D016036:Seroepidemiologic Studies
chemical_list: D000913:Antibodies, Protozoan