Serum and Milk Levels of Antibodies to Bovine Viral Diarrhoea Virus, Bovine Herpesvirus-1 and -4, and Circulation of Different Bovine Herpesvirus-4 Genotypes in Dairy Cattle with Clinical Mastitis.

Introduction: Bovine viral diarrhoea virus (BVDV) and bovine herpesvirus (BoHV)-1 and -4 are important causes of respiratory diseases and reproductive disorders of dairy cattle worldwide. Material and Methods: Investigation of BVDV and BoHV-1 and -4 antibody levels in the serum and milk of dairy cattle in a group with clinical mastitis and a healthy group was undertaken using an indirect ELISA, and identification of the BoHV-4 genotypes in clinical mastitis cases was attempted by PCR and sequencing. Results: Antibodies specific to BVDV, BoHV-1 and BoHV-4 were detected in the serum and milk of all dairy cattle with clinical mastitis. The cut-off values for BVDV and BoHV-1 in the sera and milk were extremely high in both healthy and mastitic animals. However, BoHV-4 antibodies were detected only in the clinically mastitic cattle, and BoHV-4 levels were higher in milk than in sera among these animals. Genotypes I and II of BoHV-4 were detected in the milk samples of four seropositive cows with clinical mastitis from the same herd. Conclusion: The results of this investigation demonstrate that clinical mastitis cases in the same herd may have aetiology in different BoHV-4 genotypes.

Prevalence of equine herpesvirus-1 and equine herpesvirus-4 infections in equidae species in Turkey as determined by ELISA and multiplex nested PCR.

In this report we examined the presence of specific antibodies against equine herpesvirus type 1 (EHV-1), and equine herpesvirus type 4 (EHV-4) in several equidae, including mules, donkeys, horses. The presence of EHV-1 and EHV-4 in respiratory diseases of equids, and ability of multiplex nested polymerase chain reaction (PCR) screening in simultaneous diagnosis of horses acutely infected by EHV-1 and EHV-4 were also investigated. Sera from 504 horses, mules and donkeys sampled were tested for the presence of EHV-1 and EHV-4 specific antibodies. Blood samples taken from 21 symptomatic horses and nasal swabs taken from 40 symptomatic horses were tested for the presence of EHV-1 and EHV-4 by a multiplex nested PCR. A total of 14.3% (3/21) of buffy coat samples and 32.5% (13/40) nasal swab samples were found to contain EHV-1 DNA, while 19% (4/21) buffy coat samples and 22.5% (9/40) nasal swab samples were found to be positive for EHV-4 DNA. By species, 14.5% of horses, 37.2% of mules and 24.2% of donkeys tested were EHV-1 seropositive. EHV-4 specific antibodies were detected in 237 (81.7%) of 290 horse sera tested. Results from this investigation demonstrate that EHV-1 and EHV-4 are prevalent throughout the equid population, and that donkeys and mules might also represent an important source of infection for other equids. We also showed that the multiplex nested PCR assay might be useful for diagnosis of mixed respiratory infections in horses due to EHV-1 and EHV-4.