Nationwide seroprevalence of Neospora caninum among dairy cattle in Japan.
Serum samples from 2420 clinically healthy dairy cattle, randomly selected from stored sera in 18 districts of Japan, were tested for the presence of Neospora caninum antibodies using an indirect fluorescent antibody test (titer > or =1:200). Nationwide seroprevalence is estimated at 5.7% (139/2420). Seropositive cattle were detected in all surveyed districts despite the evidence of confirmed case reports of bovine neosporosis, showing that N. caninum is widely distributed throughout Japan. Age-specific seroprevalence did not increase with cattle age, suggesting that Neospora infection is likely to be transmitted vertically rather than horizontally in Japan. Considering that N. caninum seropositive cows are thought to be more likely to abort, substantial fetal losses may be induced by N. caninum infection in Japan. Devising strategies are needed to reduce the economic impact on the Japanese dairy industry. This is the first study to investigate the nationwide seroprevalence of N. caninum in cattle in Asia.
Koiwai
Masahiro
M
Department of Diagnosis and Research, Animal Quarantine Service, Ministry of Agriculture, Forestry and Fisheries, Haramachi 11-1, Yokohama 235-0008, Japan. koiwama@maff-aqs.go.jp
Hamaoka
Takafumi
T
Haritani
Makoto
M
Shimizu
Shinya
S
Zeniya
Yumie
Y
Eto
Mariko
M
Yokoyama
Rieko
R
Tsutsui
Toshiyuki
T
Kimura
Kumiko
K
Yamane
Itsuro
I
D017677:Age Distribution; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000469:parasitology; D003048:Coccidiosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D003612:Dairying; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect / Q000662:veterinary; D007564:Japan / Q000453:epidemiology; D018688:Neospora / Q000276:immunology* / Q000302:isolation & purification; D016036:Seroepidemiologic Studies
D000913:Antibodies, Protozoan