Seroepidemiology of beef and dairy herds and fetal study of Neospora caninum in Argentina.
The purpose of the present work was to study the epidemiology of Neospora caninum in beef and dairy herds in the Humid Pampas of Argentina. The seroprevalence of N. caninum was evaluated in 2414 serum samples of cows from beef and dairy farms. An indirect fluorescent antibody test (IFAT) was used to determine specific antibodies. The sera was screened at a dilution >or=1:200 and >or=1:600 in cows with reproductive disease antecedents and without them, respectively. Cows without history of reproductive diseases from nine beef and fifteen dairy farms were grouped according to the percentage (> or <or= to 50%) of seropositive dogs. Additionally, the seroprevalence in beef and dairy cattle cohabiting in the same farm with these dogs was compared. Microscopic studies were performed in 188 aborted fetuses and/or their placentas. Formalin-fixed fetal tissues with microscopic lesions compatible with N. caninum were processed by immunohistochemistry (IHC). The seroprevalence in cows without reproductive diseases was 4.7% (19/400) for beef cattle and 16.6% (174/1048) for dairy cattle. The seroprevalence of N. caninum in dairy cattle was higher (P<0.05) in farms grouped according to the percentage (> or <or= to 50%) of seropositive dogs. The analysis of 966 serum samples from aborted cows, demonstrated positive 18.9% (41/216) and 43.1% (323/750) from beef and dairy herds, respectively. Microscopic lesions compatible with N. caninum were observed in 43 of 188 (22.8%) fetuses and/or placentas evaluated. The protozoan was identified in 29 of 43 (67.4%) aborted specimens, being the largest number of positive results in dairy fetuses. The results obtained demonstrate a high association between neosporosis and dairy herds, however, our data also reveals that N. caninum is an important risk factor for reproductive losses in the extensively farmed beef cattle in the Humid Pampas of Argentina.
Moore
Dadín Prando
DP
Consejo Nacional de Investigaciones Cienti;ficas y Técnicas (CONICET), Buenos Aires, Argentina.
Campero
Carlos Manuel
CM
Odeón
Anselmo Carlos
AC
Posso
María Adela
MA
Cano
Dora
D
Leunda
María Rosa
MR
Basso
Walter
W
Venturini
María Cecilia
MC
Späth
Ernesto
E
D037881:Aborted Fetus / Q000469:parasitology*; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D001118:Argentina / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000453:epidemiology* / Q000469:parasitology; D003048:Coccidiosis / Q000097:blood / Q000453:epidemiology / Q000662:veterinary*; D004283:Dog Diseases / Q000469:parasitology / Q000635:transmission; D004285:Dogs; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect / Q000662:veterinary; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male; D018688:Neospora / Q000276:immunology; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000453:epidemiology / Q000662:veterinary*; D016036:Seroepidemiologic Studies; D012698:Serologic Tests / Q000662:veterinary
D000913:Antibodies, Protozoan