Pathology and Molecular Detection of Rabies Virus in Ferret Badgers Associated With a Rabies Outbreak in Taiwan

Abstract

Until Rabies virus (RABV) infection in Taiwan ferret badgers (TWFB; Melogale moschata subaurantiaca) was diagnosed in mid-June 2013, Taiwan had been considered rabies free for >50 yr. Although rabies has also been reported in ferret badgers in China, the pathologic changes and distribution of viral antigens of ferret badger-associated rabies have not been described. We performed a comprehensive pathologic study and molecular detection of rabies virus in three necropsied rabid TWFBs and evaluated archival paraffin-embedded tissue blocks of six other TWFBs necropsied during 2004 and 2012. As in other RABV-infected species, the characteristic pathologic changes in TWFBs were nonsuppurative meningoencephalomyelitis, ganglionitis, and the formation of typical intracytoplasmic Negri bodies, with the brain stem most affected. There was also variable spongiform degeneration, primarily in the perikaryon of neurons and neuropil, in the cerebral cortex, thalamus, and brain stem. In nonnervous system tissues, representative lesions included adrenal necrosis and lymphocytic interstitial sialadenitis. Immunohistochemical staining and fluorescent antibody test demonstrated viral antigens in the perikaryon of the neurons and axonal or dendritic processes throughout the nervous tissue and in the macrophages in various tissues. Similar to raccoons (Procyon lotor) and skunks (Mephitidae), the nervous tissue of rabid TWFBs displayed widely dispersed lesions, RABV antigens, and large numbers of Negri bodies. We traced the earliest rabid TWFB case back to 2004.

Indigenous Wildlife Rabies in Taiwan: Ferret Badgers, a Long Term Terrestrial Reservoir

“…The recent study performed the pathologic and molecular detection of rabies virus in three Taiwan FBs and found that the earliest infected case could be traced back to 2004. In these FBs nonnervous system tissues, representative lesions included adrenal necrosis and lymphocytic interstitial sialadenitis [9]. The higher seroprevalence of rabies infection in FBs reported in Mainland China [3] also implied that FBs may be less capable reservoir animals in comparison to other wild carnivores for rabies transmission.…”

Sequencing and sequence analysis of partial nucleoprotein (N) gene and phylogenetic analysis of rabies virus field isolates from Gujarat state, India

“…2). Chiou et al [5] found 97-99% nucleotide identity of the N gene of rabies virus within three isolates from Taiwan Ferret Badgers. Jamil et al [8] revealed 98-100% nucleotide identity between N gene sequences of rabies virus from seven brain samples.…”

Risk Modeling of Bat Rabies in the Caribbean Islands

“…For example, Taiwan had been globally recognized as rabies-free since 1961. However, in 2011, the disease surveillance program was expanded to include native wildlife, and in 2013 three dead ferret badgers (Melogale moschata) tested positive for rabies virus by fluorescent antibody testing [60,61]. This new detection indicated that despite the lack of dog or human cases, rabies virus had silently remained in circulation within the wildlife population of Taiwan.…”