Detection of bovine herpesvirus 4 (BoHV-4) in dairy herds in Uruguay

Abstract

Bovine herpesvirus type 4 (BoHV-4) is a gammaherpesvirus worldwide distributed. It has been isolated in healthy and unhealthy animals with respiratory infections, vulvovaginitis, mastitis, abortions and endometritis. The persistent infection of BoHV-4 happens in monocytic cells and tissues that are part of peripherical and/or central nervous system. The reduced reproductive efficiency and the low index of procreation are the main problems in the Uruguayan breeding cattle. Reproductive tract infections include two main viruses identified in the country, infectious bovine rhinotracheitis (IBR) virus (bovine herpesvirus type 1, BoHV-1) and bovine viral diarrhea virus (BVDV). In some countries of the region have been evidenced the presence of BoHV-4 and its possible relationship with reproductive problems. Thus, the main aim of this study is to detect the presence of BoHV-4 in Uruguayan dairy herds. Commercial ELISA were used to detected BoHV-4, BoHV-1 and BVDV antibodies. PCR was used to detect the presence of BoHV-4 DNA and the products were confirmed by Sanger sequencing. Were used 597 samples of Holstein cattle from Florida, Durazno and Tacuarembó provinces. A total of 195 (32.7%) were positive to BoHV-4, 285 (47.7%) to BoHV-1 and 564 (94.4%) to BVDV antibodies. To BoHV-4 DNA, 13 of 17 samples were positives. The alignment to phylogenetic analysis showed a high degree of similarity (97.2%) among Uruguayan and worldwide strains. This is the first diagnosis of the presence of BoHV-4 in Uruguay. Future studies must evaluate the dissemination of the virus in the bovine population and the likely impact it has in the dairy healthy and national milk production.