Detection and genetic characterization of canine distemper virus isolated in civets in Vietnam

Canine distemper (CD), caused by the canine distemper virus (CDV), is a lethal systemic disease to a wide range of wild and domestic carnivorous hosts, including civets. In this study, a possible CD outbreak in a backyard farm with 32 diseased civets (Viverricula indica) in Hanoi, Vietnam, was investigated. The sick civets showed CD-like clinical signs such as anorexia, sedentary behavior, diarrhea, dermatitis, nasal, and footpad hyperkeratosis. Various tissue samples collected from the dead civets were utilized for molecular screening of CDV and histo-pathological examination. The genetic detection and characterization confirmed that samples collected from dead civets tested positive for CDV. The phylogenetic analysis based on the full-length H gene sequences indi-cated that all CDV strains isolated from civets belonged to the Asia-1 lineage and were closely related to the CDV strains previously reported from dogs in Thailand, China, and Vietnam. Histopathological examination showed severe interstitial pneumonia, hemorrhagic alveolar septa, necrotic alveolar epithelial cells, necrotic, degen-erated, or lost Purkinje cells, eosinophilic intracytoplasmic inclusion bodies, edema, and perivascular cuff. This study confirmed the detection of CDV in civets for the first time in Vietnam.

Automated summary

This study investigated a possible canine distemper (CD) outbreak in a backyard farm in Hanoi, Vietnam, where 32 diseased civets were found. These civets showed clinical signs similar to CD, and samples collected from dead civets confirmed the presence of CDV. Phylogenetic analysis revealed that the CDV strains isolated from the civets belonged to the Asia-1 lineage, closely related to strains from dogs in Thailand, China, and Vietnam. Histopathological examination showed severe pneumonia and other pathological changes. This study is the first to detect CDV in civets in Vietnam.