title: Proportion of abortions due to neosporosis among dairy cattle in Japan.
abstract: A retrospective cohort study was conducted to clarify the association between seropositive reactions to Neospora caninum and subsequent reproductive disorders among dairy cattle in Japan. A statistically significant association between Neospora seropositive reactions and abortions was observed (P=0.016), and seropositive cattle were 6.1 times more likely to abort compared to seronegative cows. No significant differences were observed between seropositive reactions and other reproductive disorders such as conception failure, perinatal death and calf mortality. As indicated by estimation of the attributable fraction, 83.6% of abortions in Neospora seropositive animals may be attributed to N. caninum. Considering seroprevalence of N. caninum in the cattle which aborted in Japan, 21.8% of abortions were estimated to be caused by neosporosis in Japan.
authors.affiliation: Department of Diagnosis and Research, Animal Quarantine Service, Ministry of Agriculture, Forestry and Fisheries, Kanagawa, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Koiwai
authors.forename: Takafumi
authors.initials: T
authors.lastname: Hamaoka
authors.forename: Makoto
authors.initials: M
authors.lastname: Haritani
authors.forename: Shinya
authors.initials: S
authors.lastname: Shimizu
authors.forename: Kumiko
authors.initials: K
authors.lastname: Kimura
authors.forename: Itsuro
authors.initials: I
authors.lastname: Yamane
mesh_terms: D000034:Abortion, Veterinary / Q000453:epidemiology / Q000209:etiology / Q000662:veterinary*; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology*; D003048:Coccidiosis / Q000150:complications / Q000453:epidemiology / Q000662:veterinary*; D015331:Cohort Studies; D005260:Female; D007564:Japan / Q000453:epidemiology; D018688:Neospora; D011247:Pregnancy; D012189:Retrospective Studies; D016036:Seroepidemiologic Studies