Experimental Infection of White-Tailed Deer Fawns (Odocoileus Virginianus) With Bovine Viral Diarrhea Virus Type-1 Isolated From Free-Ranging White-Tailed Deer

Abstract

ABSTRACT:The objective of the current study was to elucidate the within-host dynamics of bovine viral diarrhea virus (BVDV) type-1 infection to better understand how this virus could be maintained in white-tailed deer (Odocoileus virginianus, WTD) populations. The BVDV type-1 used in this study was originally isolated from a free-ranging WTD in Indiana. Four fawns were intranasally inoculated with 2 ml BVDV type-1 strain 544 WTD at a 10 6 tissue culture infectious dose (TCID 50 )/ml. Two fawns were inoculated with sham inoculum (negative controls). Animals were bled on days 27, 0, 1, 7, and 14 postinoculation (PID) for a complete blood count, chemistry panel, buffy coat (BC), real-time RT-PCR, and virus neutralization (VN). On days 7 and 14 PID, nasal and rectal swabs were obtained for RT-PCR and two of the virus-inoculated fawns and one of the negative controls fawns were euthanized. At necropsy, multiple samples were obtained for histopathology and in situ hybridization (ISH). Quantitative RT-PCR was performed on serum, BC, nasal, and rectal swabs. All animals tested negative for BVDV type 1 neutralizing antibodies on day 0 and animals in the control group remained seronegative throughout the study. No gross lesions were observed at necropsy. BVDV was isolated from lung and pooled lymph nodes from all BVDV-inoculated fawns on days 7 and 14 PID. Infected deer had lymphoid depletion, apoptosis, and lymphoid necrosis in the Peyer's patches and mesenteric lymph nodes. BVDV was detected in lymphoid tissues of infected animals by ISH. No lesions or virus were identified in control fawns. On day 7 PID, samples from two virus-inoculated fawns were positive for BVDV by virus isolation and RT-PCR from BC and nasal swab samples. One fawn was also positive on a rectal swab. Nasal and rectal swabs from all animals were negative on day 14. Results indicate that infection of WTD with BVDV is possible, and leads to histologic lesions in variety of tissues. In addition, virus shedding into the environment through feces and other secretions is likely.

Distribution of Bovine Viral Diarrhoea Virus Antigen in Persistently Infected White-Tailed Deer (Odocoileus virginianus)

“…Lower than expected antigen expression in lymphoid tissues likely resulted from the often severe lymphoid depletion observed in Peyer's patches, thymus and lymph nodes. Prominent lymphoid depletion was also detected in a previous description of PI white-tailed deer (Duncan et al, 2008a) and whitetailed deer fawns following acute experimental infection (Raizman et al, 2011). While decreases in circulating lymphocytes and lymphoid depletion are common in acutely infected cattle, lymphoid depletion is not a common feature in PI cattle, contrasting with the findings in deer (Walz et al, 2001;LieblerTenorio et al, 2002LieblerTenorio et al, , 2004.…”

“…Among freeranging species, BVDV infections of white-tailed deer have recently received much attention. The virus was identified in free-ranging white-tailed deer Duncan et al, 2008a;Passler et al, 2008;Pogranichniy et al, 2008) and experimental infections resulted in clinical signs analogous to those in cattle (Ridpath et al, 2007(Ridpath et al, , 2008Raizman et al, 2009). White-tailed deer can become persistently infected with BVDV and shed the virus at similar levels to cattle , which can result in efficient transmission to other deer (Passler et al, 2009a).…”

“…Clinical disease is reported in domesticated small ruminants, swine and camelids, and the health effects of BVDV-associated disease are similar to those in cattle with the most severe effects on reproductive health (Taylor et al, 1977;Stewart et al, 1980;Loken and Bjerkas, 1991;Hegazy et al, 1996;Goyal et al, 2002;Carman et al, 2005). Few reports of natural BVDV-associated disease in heterologous species exist, and the role of BVDV as the causative pathogen in some case reports is equivocal (Richards et al, 1956;Romvary, 1965;Brass et al, 1966;Nettleton et al, 1980;Neumann et al, 1980;Feinstein et al, 1987;Diaz et al, 1988). Among freeranging species, BVDV infections of white-tailed deer have recently received much attention.…”

Experimental Infection of Pregnant Pyrenean Chamois (Rupicapra Pyrenaica) With Border Disease Virus Subtype 4

“…In wild ruminants, pestivirus pathology is poorly known. Experimental infection with BVDV has been carried out in white-tailed deer (Odocoileus virginianus; Passler et al, 2007;Ridpath et al, 2007;Duncan et al, 2008;Raizman et al, 2009), elk (Cervus elaphus; Tessaro et al, 1999), and mule deer (Odocoileus hemionus; Van Campen et al, 1997). In most of these studies, no clinical signs were reported while abortion, fever, and lymphocyte depletion were described in others (Duncan et al, 2008;Raizman et al, 2009).…”

Monitoring for Bovine Viral Diarrhea Virus in Austrian Red Deer (Cervus elaphus elaphus) by using Ear-notch Samples

“…Persistent infection and histopathologic lesions have been well documented in wild ungulates, especially in mule and whitetailed deer fawns and adults (Duncan et al, 2008a, b;Ridpath et al, 2008;Passler et al, 2009;Raizman et al, 2009). However, in pregnant white-tailed deer the pathogenesis of transplacental BVDV infection is still incompletely understood.…”