Transmission and pathogenicity of canine H3N2 influenza virus in dog and guinea pig models
Ratanaporn Tangwangvivat, Supassama Chaiyawong, Nutthawan Nonthabenjawan, Kamonpan Charoenkul, Taveesak Janethanakit, Kitikhun Udom, Sawang Kesdangsakonwut, Rachod Tantilertcharoen, Aunyaratana Thontiravong, Alongkorn Amonsin
Abstract
Abstract Background Influenza A virus causes respiratory disease in many animal species as well as in humans. Due to the high human-animal interface, the monitoring of canine influenza in dogs and the study of the transmission and pathogenicity of canine influenza in animals are important. Methods Eight-week-old beagle dogs (Canis lupus familaris) (n = 13) were used for the intraspecies transmission model. The dogs were inoculated intranasally with 1 ml of 10 6 EID 50 per ml of canine H3N2 influenza virus (A/canine/Thailand/CU-DC5299/2012) (CIV-H3N2). In addition, 4-week-old guinea pigs ( Cavia porcellus) (n = 20) were used for the interspecies transmission model. The guinea pigs were inoculated intranasally with 300 µl of 10 6 EID 50 per ml of CIV-H3N2. Results For the Thai CIV-H3N2 challenged in the dog model, the incoculated and direct contact dogs developed respiratory signs at 2 dpi. The dogs shed the virus in the respiratory tract at 1 dpi and developed an H3-specific antibody against the virus at 10 dpi. Lung congestion and histopathological changes in the lung were observed. For the Thai CIV-H3N2 challenge in the guinea pig model, the incoculated, direct contact and aerosol-exposed guinea pigs developed fever at 1–2 dpi. The guinea pigs shed virus in the respiratory tract at 2 dpi and developed an H3-specific antibody against the virus at 7 dpi. Mild histopathological changes in the lung were observed. Conclusion The result of this study demonstrated evidence of intraspecies and interspecies transmission of CIV-H3N2 in a mammalian model.