Molecular Detection and Genetic Characterization of Japanese Encephalitis Virus in Animals from 11 Provinces in China

Abstract

Japanese encephalitis virus (JEV), which uses a mosquito primary vector and swine as a reservoir host, poses a significant risk to human and animal health. JEV can be detected in cattle, goats and dogs. A molecular epidemiological survey of JEV was conducted in 3105 mammals from five species, swine, fox, racoon dog, yak and goat, and 17,300 mosquitoes from 11 Chinese provinces. JEV was detected in pigs from Heilongjiang (12/328, 3.66%), Jilin (17/642, 2.65%), Shandong (14/832, 1.68%), Guangxi (8/278, 2.88%) and Inner Mongolia (9/952, 0.94%); in goats (1/51, 1.96%) from Tibet; and mosquitoes (6/131, 4.58%) from Yunnan. A total of 13 JEV envelope (E) gene sequences were amplified in pigs from Heilongjiang (5/13), Jilin (2/13) and Guangxi (6/13). Swine had the highest JEV infection rate of any animal species, and the highest infection rates were found in Heilongjiang. Phylogenetic analysis indicated that the predominant strain in Northern China was genotype I. Mutations were found at residues 76, 95, 123, 138, 244, 474 and 475 of E protein but all sequences had predicted glycosylation sites at ′N154. Three strains lacked the threonine 76 phosphorylation site from non-specific (unsp) and protein kinase G (PKG) site predictions; one lacked the threonine 186 phosphorylation site from protein kinase II (CKII) prediction; and one lacked the tyrosine 90 phosphorylation site from epidermal growth factor receptor (EGFR) prediction. The aim of the current study was to contribute to JEV prevention and control through the characterization of its molecular epidemiology and prediction of functional changes due to E-protein mutations.

A scoping review of evidence of naturally occurring Japanese encephalitis infection in vertebrate animals other than humans, ardeid birds and pigs

“…Studies were published from 1947 [37] to 2023 [38] and were mainly conducted in Asia (n = 55; Figure S1), with the highest number in Japan (n = 17), followed by India (n = 11), and China (n = 8). Three studies were conducted in locations outside the current known distribution of JEV circulation: North America (n = 1; United States [39]) and Europe (n = 2; Italy [40, 41]).…”

“…(2022), sampled bats had appeared healthy. Japanese encephalitis virus was also detected in other mammals including farmed Caprinae and Suidae in China (each with prevalence 2% in a survey which also included fox [Vulpes vulpes], racoon dog [Nyctereutes procyonoides] and yak [Bos grunniens] in which no direct evidence of JEV infection was detected [57]), a single Thoroughbred racehorse in Hong Kong (Equus caballus [42]), cattle in Japan [43,45], and two pet meerkats in Thailand (S. suricatta [46]). The racehorse had shown signs of severe neurological disease and viral RNA consistent with both Genotype I and II JEV strains was detected in spinal cord tissue by RT-PCR targeting the NS5 and E genes.…”

Rapid Generation of Recombinant Flaviviruses Using Circular Polymerase Extension Reaction

“…JEV is a clinically important arthropod-borne zoonotic flavivirus circulating between humans and vertebrate hosts via mosquito bites. Domestic pigs are the main source of JEV in a zoonotic cycle for their ability to amplify JEV to high titers and their close proximity to humans [ 17 , 18 ]. JEV poses a huge threat to domestic pig farms and causes economic damage [ 18 ].…”

“…Domestic pigs are the main source of JEV in a zoonotic cycle for their ability to amplify JEV to high titers and their close proximity to humans [ 17 , 18 ]. JEV poses a huge threat to domestic pig farms and causes economic damage [ 18 ]. JEV infection in humans causes clinical presentations ranging from febrile illness to viral encephalitis.…”