Molecular epidemiology of Japanese encephalitis virus in pig population of Odisha, Assam and Manipur states of India

Ankita Datey,Leichombam Mohindro Singh,Uttam Rajkhowa,Birendra Kumar Prusty,Tanuja Saswat,Prabhudutta Mamidi,Luit Moni Barkalita,Rupam Dutta,K Chandradev Sharma,Dinabandhu Sahoo,Probodh Borah,Sarangthem Indira Devi,Soma Chattopadhyay

doi:10.1016/j.meegid.2020.104325

Abstract

Japanese encephalitis virus (JEV) comes under the family Flaviviridae and genus flavivirus. Pigs act as reservoir and amplifying intermediate host for JEV. The current investigation was conducted to understand the prevalence of JEV infection in pigs in three different geographical sites in India (Odisha, Assam and Manipur). Total 857 serum samples were tested by ELISA and RT-PCR, while only RT-PCR was performed in case of 275 tonsils tissues for detection of JEV. It was observed that JEV prevalence was highest in Manipur (positive 39, 25.5% in serum and 10% in tonsil) but lower in Assam (positive 15, 3.8% in serum and 0% in tonsils) and Odisha (positive 7, 1.5% in serum and 3.7% in tonsils). Genotype III (GIII) of JEV was the dominant genotype. Further, analysis of E gene revealed sporadic mutations of S83G, H76P, E78Q, C55S, and S64W along with two consistent mutations V46S and V51I in GIII. Whereas, a single mutation S118N was observed in the GI strain. In conclusion, the high JE virus infection rate of pig in the current locations suggests the need for continuous surveillance of this virus in pigs which will ultimately help to adopt an effective control strategy to prevent the spread of JE infection to human.

Highlights

Flaviviruses are important human and animal pathogens with worldwide distribution.Japanese encephalitis virus (JEV), belonging to this family affects the children below 10 years and the mortality rate can be upto 30% [1] and about 30%-50% of survivors develop permanent neurologic disorder or psychiatric sequelae [2]
Japanese encephalitis is one of the contributing factors in acute encephalitis syndrome cases reported across India as well as Asia
Young naive human population are affected with JEV

Summary

Introduction

Japanese encephalitis virus (JEV), belonging to this family affects the children below 10 years and the mortality rate can be upto 30% [1] and about 30%-50% of survivors develop permanent neurologic disorder or psychiatric sequelae [2]. JEV maintains its life cycle between vectors and reservoir hosts such as pigs, wading birds and bats [2] from where the virus is transmitted to the dead end hosts such as humans and horses which do not develop high viremia to infect mosquito hosts [9, 10]. Evidence for the occurrence of Japanese encephalitis virus genotype I and III infection associated with acute encephalitis in patients of West Bengal, India, 2010. The dynamics of Japanese encephalitis virus circulation in sentinel pigs between a rural and a peri-urban setting in Cambodia. Pathogenic and Fulmali PV, Sapkal GN, Athawale S, Gore MM, Mishra AC, Bondre VP

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