Experimental Infection of Reindeer with Cervid Herpesvirus 2

Abstract

Cervid herpesvirus 2 (CvHV2) has been isolated from reindeer (Rangifer tarandus tarandus), and serological data indicate that in reindeer this virus is endemic in Fennoscandia, Alaska, Canada, and Greenland. CvHV2 has been described as a cause of subclinical genital infections in reindeer, but little information on primary infections exists. In this study, six seronegative and presumably pregnant reindeer were allocated to one of two groups. Two animals were inoculated with CvHV2 intratracheally, and two animals intravaginally, with one control animal in each group receiving sterile water. Mild hyperthermia and serous discharges from the vagina and nose were observed. No abortions were recorded, but one calf died shortly after birth. Inoculated animals seroconverted and had neutralizing antibodies after days 7 to 10 postinfection. CvHV2 was detected by PCR in nasal and vaginal swabs from animals in both groups but could be isolated only from nasal swabs in the respiratory group and from vaginal swabs in the genital group. CvHV2 was detected by PCR in various organs and tissues postmortem. In control animals, the virus could not be isolated in spite of PCR-positive nasal and vaginal swab samples and some degree of positive immunostaining. One of the animals that were inoculated intratracheally developed a hemorrhagic, necrotizing bronchopneumonia, which was CvHV2 positive by PCR and immunohistochemistry. We conclude that CvHV2 can cause systemic infection, that both genital and respiratory inoculations can lead to virus shedding, and that the virus can infect the fetus in utero.

Cervid herpesvirus 2 and not Moraxella bovoculi caused keratoconjunctivitis in experimentally inoculated semi-domesticated Eurasian tundra reindeer

“…This is in line with previous inoculation experiments in reindeer with CvHV2 [36], in which a humoral immune response generally was not evident until days 8–10 p.i. Thus, the rapid onset of clinical signs after inoculation of CvHV2 in the conjunctiva indicates that a primary specific immune response will develop too late to be protective against disease in previously unexposed animals.…”

Are we facing new health challenges and diseases in reindeer in Fennoscandia?

“…Recent reports have revealed that latent infections might be activated by glucocorticosteroids, and that infections are associated to mucosal lesions in the gastro-intestinal tract. Further, CvHV2 can be transferred from mother to the foetus, can cause abortion and also possibly serve as the contagious component in the disease etiology of infectious keratoconjunctivitis (IKC) (Das Neves et al, 2009b;Tryland et al, 2009). CvHV2 infections may gain increased importance if animal density and general stress load of animals increases (Das Neves et al, 2009a).…”

Ocular Histopathological Findings in Semi-Domesticated Eurasian Tundra Reindeer (Rangifer tarandus tarandus) with Infectious Keratoconjunctivitis after Experimental Inoculation with Cervid Herpesvirus 2

“…In a previous experimental infection with CvHV2 in reindeer, where the animals were inoculated intratracheally or intravaginally [29], immunohistochemistry for CvHV2 of lung and uterine tissues showed strong positive staining of goblet cells of the respiratory epithelium and basal cells of endometrial glands. Positive virus staining was also observed in leukocytes.…”

“…This virus tropism is consistent with the severe epithelial and glandular damage described in the eye tissues in the present study, and with our observation of enveloped viral particles and viral capsids in the necrotic eye tissue, and viral capsids inside a neutrophil, by electron microscopy ( Figure 5). Unfortunately, the monoclonal antibodies used in the study by das Neves et al [29] are no longer available.…”