Persistent Viral Shedding during Asymptomatic Aleutian Mink Disease Parvoviral Infection in a Ferret

Abstract

Abstract.A 2-year-old domestic ferret that appeared clinically healthy was repeatedly seropositive for Aleutian mink disease parvovirus (ADV) over a 2-year observation period. Antibody titers, determined by counter-immunoelectrophoresis, ranged from 1024 to 4096. Viral DNA also was identified in serum, urine, feces, and blood cell fractions by polymerase chain reaction analysis. Ultimately, DNA in situ hybridization revealed ADV DNA in histologic sections of various tissues and organs. These data indicate that this asymptomatic ferret was persistently infected with ADV.Key words: Aleutian disease virus; counter-immunoelectrophoresis; PCR; in situ hybridization. Aleutian mink disease parvovirus (ADV) is naturally occurring parvovirus that infects mustelids such as mink and ferrets. 3,7,8 The disease was first described in Aleutian mink, which have an increased susceptibility to disease resulting from a Chediak-Higashi-like defect in lysosomal membrane function and reduced cell-mediated immune responses necessary for combating viral infections. 4 Normal or wild-type mink are asymptomatic or have mild to moderate clinical signs of disease, chronically elevated antibody titers, and no detectable viremia or transient viremia depending on the strain of ADV. 6 Experimental infections of ferrets with minkderived strains of ADV have resulted in clinical scenarios similar to that of mink with dark coat colors. 6,15 Natural ADV outbreaks in ferret shelters and multiple ferret households have been increasingly reported. 11,14 Common clinical signs associated with ADV infection in ferrets include chronic progressive weight loss, cachexia, malaise, and melena. Ataxia leading to posterior paralysis, tremors, and convulsions has also been observed. 11,14 Little is known about the pathogenesis of natural ADV infection in ferrets or the route by which viral shedding occurs.Serum from a clinically normal, 2-year-old, male, sable point ferret was sent to the University of Georgia College of Veterinary Medicine to test for ADV. After an initial positive test result, serum samples from the ferret were submitted intermittently for anti-ADV antibody testing over a period of 1.5 years. Counter-immunoelectrophoresis was performed to determine an endpoint antibody titer within the range of 1:4 through 1:16,384. Nine serum samples were consistently positive for anti-ADV antibodies with a titer Ն1024 over a period of 1.5 years (Fig. 1). Serum was also tested for the presence of ADV DNA by using a polymerase chain reaction (PCR)-based assay. 12 Eight of nine serum samples assayed yielded the appropriately sized band (Fig. 2).Additional testing of anticoagulated whole blood was done to determine which fractions were associated with viral DNA. A 1:1 mixture of PBS-diluted, heparinized blood was separated into 3 layers by using gradient centrifugation. a A commercial kit b was used to extract and purify DNA from the erythrocytes, buffy coat, and plasma fractions. These DNA samples were evaluated by PCR analysis to detect ADV. The acellular pla...

Full genetic characterization and epidemiology of a novel amdoparvovirus in striped skunk (Mephitis mephitis)

“…2 However, because of the wide range of potentially susceptible hosts, these viruses have also raised major concerns outside of the fur industry as they represent a serious risk for wild animals and pose a threat to endangered species. 7, 8 The presence of asymptomatic individuals, whose existence has already been proven among mink and ferrets, 34, 35 certainly facilitates viral dispersion, making new hosts more accessible. The vast majority of the skunks that were sources or viruses for this study presented with an apparently sub-clinical infection, 10 consistent with a presumed role of these animals as amdoparvovirus carriers and natural reservoir hosts, as already postulated by others.…”

Novel Amdovirus in Gray Foxes

“…Parvoviridae; it can infect diverse breeds of farmed and feral mink, in addition to other mustelids (e.g., ferrets, otters), raccoons, and foxes (1,2). AMDV has an ≈5-kb single-stranded DNA genome and, like other parvoviruses, replicates through a rolling-hairpin mechanism (3).…”

High molecular polymorphism of the hypervariable region in the VP2 gene of Aleutian mink disease virus

“…The sequence encoding the VP2 capsid protein contains a hypervariable region. Mutations in the nucleotide sequence encoding the capsid protein (VP1 and VP2) determine the pathogenicity (Pennick et al, 2005). McKenna et al (1999) confirmed that this localization may play an important role in tissue tropism and pathogenicity as well as in antigenic properties, as a strain-specific epitope may be situated in this region.…”