A novel mutation (S227T) in domain II of the envelope gene of Japanese encephalitis virus circulating in North India.

Japanese encephalitis (JE) is an important arboviral infection of public health concern. There is a significant variation in mortality (10-30%) in JE viral infection. Epidemics of JE have become regular features in the northern states of India. The recent resurgence of the A226V mutation leading to a widespread Chikungunya epidemic motivated the investigators to search for any such mutational occurrence with Japanese encephalitis virus (JEV) isolated from this region. This study looked for mutation of clinical strains at amino-acid positions 176, 177, 227, 244, 264 and 279. A novel mutation S227T was detected corresponding to the loop region of domain II, E gene of JEV in comparison to Indian and other isolates from different parts of the world. Genotype III was found to be circulating in this geographical area. Further studies are required to ascertain its role in JE pathogenesis and vector competency.