Classical Swine Fever in Wild Hog: Report of its Prevalence in Northeast India

Classical swine fever virus (CSFV) is the causative agent of a highly contagious disease, hog cholera in pigs. The disease is endemic in many parts of the world and vaccination is the only way to protect the animals from CSFV infection. Wild hogs belong to the species Sus Scrofa Cristatus under the family Suidae are quite susceptible to CSFV infection. The epidemiological role concerning classical swine fever (CSF) in India is largely unknown. We report here the three isolated cases of CSF in wild hogs from three National parks, namely Kaziranga National Park, Manas National Park and Jaldapara National Park, from north-east part of India. The post-mortem and histopathological findings were clearly indicative for CSFV infection. The presence of CSFV genome was demonstrated in several organs and tissues collected from hogs died due to viral infection. In addition, CSF-specific antibodies were detected in two wild hogs as well as in eighteen feral pigs from the same locations. The phylogenetic analysis of the partial E2 protein gene and 5' untranslated region of CSFV isolates from the wild hog showed identities with genotype 2.2 of the Indian isolates. Occurrence of CSF in wild hogs may pose a potent threat in the epidemiology of the virus in Northeast part of India. To the best of our knowledge, the report presented in the manuscript is the first comprehensive report on CSF in wild hogs form Northeast India. The findings reported would help us to understand the epidemiology and biology of CSFV in wild animals.