Detection of bovine herpesvirus 1 in genital organs of naturally infected cows.

Bovine herpesvirus 1 (BoHV-1) is a causative agent of respiratory diseases in cattle, and infection with BoHV-1 can cause reproductive failure. There are few studies regarding infections in natural conditions in the reproductive organs of bovine animals. In this context, this study investigated the presence of BoHV-1 in the uterus, oviducts, and ovarian tissues of naturally infected cows. The three genital structures were evaluated for the presence or absence of BoHV-1 by immunofluorescence assay using confocal scanning laser microscopy. Blood and genital organ samples of 75 cows unvaccinated against BoHV-1 were used. Fragments of uterus, oviduct, and ovarian tissue were processed and analyzed by confocal scanning laser microscopy. Neutralization by antibodies was observed in 54.7% (41/75) of the serum samples tested. BoHV-1 were detected in the uterus of all the seropositive cows. The oviducts contained BoHV-1 in 73.2% of the samples and the ovaries contained BoHV-1 in 58.5% of the samples from seropositive animals. The presence of the virus was not observed in any of the genital organs of seronegative animals. There was no correlation between the antibody titer and the detection of BoHV-1 in positive tissue in the different genital organs or with the number of infected structures per animal. The detection of BoHV-1 in 100% of the uterus samples from seropositive cows suggests that this organ may be a source of infection for the fetus, resulting in abortion. Further studies on the mechanism by which BoHV-1 infects the fetus via the uterine route should be performed.