Precolostral serology in calves born from Neospora-seropositive mothers.
The present study was designed to exploratively determine (a) how many healthy calves, born from seropositive mothers, were also precolostrally seropositive; (b) how many precolostrally negative calves became postcolostrally positive; and (c) in these calves, how the IgG1/IgG2 situation developed pre- and postcolostrally. All calves were born from mothers that were determined to be seropositive in a conventional Neospora caninum-ELISA and by immunoblotting. When the diagnostic performance of the conventional ELISA was compared with that of immunoblotting and an IgG1/IgG2-ELISA in the calves, the latter two exhibited a higher sensitivity: From a total of 15 precolostral calf sera, 7 were positive in the conventional ELISA (diagnostic sensitivity 47%) compared to 15 that were positive by immunoblotting (diagnostic sensitivity 100%) and 12 that were positive by the IgG1/IgG2-ELISA (diagnostic sensitivity 80%). With regard to IgG1/IgG2 findings in the dams, IgG2 appeared as the dominant subclass in the humoral immune response of adult cattle, while in calves, IgG1 appeared as the main prenatally/precolostrally reactive antibody isotype. Provided that precolostral seropositivity reflects postnatal persistent infection with N. caninum, we then postulate that, basically, all of our study calves born form N. caninum-seropositive mothers were prenatally infected with the parasite, and may, thus, all become members of the next transmitting generation.
Institute of Parasitology, Vetsuisse Faculty, University of Bern, Laenggass-Strasse 122, CH-3012, Bern, Switzerland.
Daniela
D
Staubli
Heinz
H
Sager
Corinne
C
Haerdi
Michael
M
Haessig
Bruno
B
Gottstein
D000818:Animals; D000831:Animals, Newborn / Q000097:blood / Q000469:parasitology*; D000953:Antigens, Protozoan; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology*; D003048:Coccidiosis / Q000276:immunology / Q000635:transmission / Q000662:veterinary*; D003126:Colostrum / Q000502:physiology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D018445:Infectious Disease Transmission, Vertical / Q000662:veterinary*; D018688:Neospora / Q000276:immunology / Q000302:isolation & purification*; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic; D012698:Serologic Tests
D000953:Antigens, Protozoan