Etiology, pathogenesis and future prospects for developing improved vaccines against bluetongue virus: A Review

Abstract

Bluetongue is a viral disease that primarily affects sheep, occasionally goats and deer and, very rarely, cattle. The disease is caused by an icosahedral, non-enveloped, double-stranded RNA (dsRNA) virus within the Orbivirus genus of the family Reoviridae. It is non-contagious and is only transmitted by insect vectors. BTV serotypes are known to occur in Africa, Asia, South America, North America, Middle East, India, and Australia generally between latitudes 35°S and 50°N. It occurs around the Mediterranean in summer, subsiding when temperatures drop in winter. The replication phase of the bluetongue virus (BTV) infection cycle is initiated when the virus core is delivered into the cytoplasm of a susceptible host cell. The 10 segments of the viral genome remain packaged within the core throughout the replication cycle, helping to prevent the activation of host defense mechanisms that would be caused by direct contact between the dsRNA and the host cell cytoplasm. This review presents comprehensive information on etiology, pathogenesis, prevention and control of the disease.

Key words: Bluetongue, orbivirus, pathogenesis, prevention.