Seroprevalence of bovine leukemia virus (BLV) infection in dairy cattle in Isfahan Province, Iran.
Bovine leukemia virus (BLV), the causative agent of enzootic bovine leukosis (EBL) is an exogenous C-type oncovirus in the Retroviridae family. It causes significant economic losses associated with the costs of control and eradication programs due to carcass condemnation at slaughter and restrictions of export of cattle and semen to importing countries. The main objective of this research was to determine the seroprevalence of BLV infection in cattle herds in central region of Iran (Isfahan province) using a commercial enzyme-linked immunosorbent assay (ELISA) to detect serum antibodies against BLV. Samples of blood serum were collected from 403 female dairy cattle (Holstein-Friesian) from 21 livestock farms and 303 animals (81.9%) were BLV seropositive. A significant association was found between age as a potential risk factor and BVL seroprevalence with animals ≥ 4 years (86.6%) having a significantly (χ(2) = 35.6, p < 0.001) higher seroprevalence compared to those < 4 years (54.2%). We found no significant statistical association between seroprevalence and pregnancy, lactation status and farming systems as potential risk factors in this study (p > 0.1). It is concluded that BLV infection is a very common problem in the study area. Hence, control measures should be instituted to combat the disease and further studies are required to investigate the impact of this disease on dairy production in the country.
Quality Control Management, Razi Vaccine and Serum Research Institute, PO Box 311975-148, Karaj, Iran. h.morovati@rvsri.ir
Hassan
H
Morovati
Edris
E
Shirvani
Vahid
V
Noaman
Mohsen
M
Lotfi
Morteza
M
Kamalzadeh
Alireza
A
Hatami
Masoume
M
Bahreyari
Zahra
Z
Shahramyar
Mohammad H
MH
Morovati
Mahmoud
M
Azimi
Davoud
D
Sakhaei
D000367:Age Factors; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002417:Cattle; D003612:Dairying; D016583:Enzootic Bovine Leukosis / Q000453:epidemiology* / Q000821:virology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D007492:Iran / Q000453:epidemiology; D001909:Leukemia Virus, Bovine; D011247:Pregnancy; D016036:Seroepidemiologic Studies
D000914:Antibodies, Viral