Discovery and Preliminary Characterization Including Viral Shedding Patterns of a New Amdoparvovirus Infection in a Group of Red Pandas (Ailurus fulgens)
Using metagenomics, we discovered a novel amdoparvovirus tentatively named red panda amdoparvovirus (RpAPV) in red pandas. The virus, while phylogenetically related, is distinct from Aleutian mink disease virus (Carnivore amdoparvovirus 1) and other recently described amdoparvoviruses in foxes and skunks. Using histology, PCR, in situ hybridization and electron microscopy, we analyzed the prevalence, shedding patterns, tissue distribution, and disease association of RpAPV in a group of six red pandas from a single zoological collection. A six-month fecal shedding survey in four animals found that 32 of 34 samples contained virus and 3 animals shed at all collection time points. This was followed by a separate 8-week shedding survey of two pandas during their arrival into quarantine and movement into the exhibit during which frequent intermittent shedding was documented. Full-length RpAPV strains from two animals had 12% sequence divergence, demonstrating genetic diversity even among in-contact animals. In a retrospective analysis, RpAPV was also detected in tissues of four animals, housed at the same exhibit and necropsied over a twelve-year span. RpAPV was associated with clinical sequelae in one geriatric animal that had viral-associated peritonitis, pancreatitis, and myocarditis. Three other necropsied animals had detectable low-level viral nucleic acid in lymph nodes and oral or intestinal epithelium. RpAPV is a persistent and productive infection among this cohort of red pandas with variable clinical expression. Work in progress includes a fecal survey to determine the prevalence of viral shedding throughout the North American SSP population and uncovering any association with other carnivore APVs.
The authors would like to thank staff of the Sacramento Zoo for care of the red pandas and collection of the samples.