scholarly journals The feasibility of field collected pig oronasal secretions as specimens for the virologic surveillance of Japanese encephalitis virus

2021 ◽  
Vol 15 (12) ◽  
pp. e0009977
Author(s):  
Shyan-Song Chiou ◽  
Jo-Mei Chen ◽  
Yi-Ying Chen ◽  
Min-Yuan Chia ◽  
Yi-Chin Fan
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Encephalitis Virus ◽  
Mosquito Vector ◽  
Rt Pcr ◽  
Viral Rnas ◽  
Epidemic Area ◽  
Route Of Transmission ◽  
Pig Farm ◽  
Blood Specimens

Virologic surveillance of Japanese encephalitis virus (JEV) relies on collecting pig blood specimens and adult mosquitoes in the past. Viral RNAs extracted from pig blood specimens suffer from low detecting positivity by reverse transcription PCR (RT-PCR). The oronasal transmission of the virus has been demonstrated in experimentally infected pigs. This observation suggested oronasal specimens could be useful source in the virus surveillance. However, the role of this unusual route of transmission remains unproven in the operational pig farm. In this study, we explore the feasibility of using pig oronasal secretions collected by chewing ropes to improve the positivity of detection in commercial pig farms. The multiplex genotype-specific RT-PCR was used in this study to determine and compare the positivity of detecting JEV viral RNAs in pig’s oronasal secretions and blood specimens, and the primary mosquito vector. Oronasal specimens had the overall positive rate of 6.0% (95% CI 1.3%–16.6%) (3/50) to 10.0% (95% CI 2.1%–26.5%) (3/30) for JEV during transmission period despite the negative results of all blood-derived specimens (n = 2442). Interestingly, pig oronasal secretions and female Culex tritaeniorhynchus mosquito samples collected from the same pig farm showed similar viral RNA positive rates, 10.0% (95% CI 2.1%–26.5%) (3/30) and 8.9% (95% CI 2.5%–21.2%) (4/45), respectively (p> 0.05). Pig oronasal secretion-based surveillance revealed the seasonality of viral activity and identified closely related genotype I virus derived from the mosquito isolates. This finding indicates oronasal secretion-based RT-PCR assay can be a non-invasive, alternative method of implementing JEV surveillance in the epidemic area prior to the circulation of virus-positive mosquitoes.

scholarly journals Experimental Evaluation of the Role of Ecologically-Relevant Hosts and Vectors in Japanese Encephalitis Virus Genotype Displacement

Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 32 ◽  
Author(s):  
Ajit K. Karna ◽  
Richard A. Bowen
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Experimental Evaluation ◽  
Encephalitis Virus ◽  
Viral Fitness ◽  
Avian Host ◽  
Mosquito Vector ◽  
Virus Genotype ◽  
Southern Asia

Japanese encephalitis virus (JEV) is a flavivirus that is maintained via transmission between Culex spp. mosquitoes and water birds across a large swath of southern Asia and northern Australia. Currently JEV is the leading cause of vaccine-preventable encephalitis in humans in Asia. Five genotypes of JEV (G-I–G-V) have been responsible for historical and current outbreaks in endemic regions, and G-I and G-III co-circulate throughout Southern Asia. While G-III has historically been the dominant genotype worldwide, G-I has gradually but steadily displaced G-III. The objective of this study was to better understand the phenomenon of genotype displacement for JEV by evaluating both avian host and mosquito vector susceptibilities to infection with representatives from both G-I and G-III. Since ducks and Culex quinquefasciatus mosquitoes are prevalent avian hosts and vectors perpetuating JEV transmission in JE endemic areas, experimental evaluation of virus replication in these species was considered to approximate the natural conditions necessary for studying the role of host, vectors and viral fitness in the JEV genotype displacement context. We evaluated viremia in ducklings infected with G-I and G-III, and did not detect differences in magnitude or duration of viremia. Testing the same viruses in mosquitoes revealed that the rates of infection, dissemination and transmission were higher in virus strains belonging to G-I than G-III, and that the extrinsic incubation period was shorter for the G-I strains. These data suggest that the characteristics of JEV infection of mosquitoes but not of ducklings, may have play a role in genotype displacement.

scholarly journals A dataset of distribution and diversity of mosquito-associated viruses and their mosquito vectors in China

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Evans Atoni ◽  
Lu Zhao ◽  
Cheng Hu ◽  
Nanjie Ren ◽  
Xiaoyu Wang ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Mosquito Species ◽  
Encephalitis Virus ◽  
Health Concern ◽  
Mosquito Vector ◽  
Mosquito Vectors ◽  
Culex Flavivirus ◽  
Conference Papers

Abstract Mosquito-borne viruses such as Zika virus, Japanese Encephalitis virus and Dengue virus present an increasing global health concern. However, in-depth knowledge of the distribution and diversity of mosquito-associated viruses and their related vectors remains limited, especially for China. To promote their understanding, we present the first comprehensive dataset of the distribution and diversity of these viruses and their related vectors in China (including Taiwan, Hong Kong and Macau). Data was drawn from peer-reviewed journal articles, conference papers and thesis publications in both English and Chinese. Geographical data on mosquito-associated viruses’ occurrence and related mosquito vector species was extracted, and quality-control processes employed. This dataset contains 2,428 accounts of mosquito-associated viruses’ and mosquito species geo-referenced occurrences at various administrative levels in China. The prevalent mosquito-associated virus includes Japanese encephalitis virus, Dengue virus, Banna virus and Culex flavivirus, whereas the abundant mosquito vectors are Culex tritaeryohynchus, Aedes albopictus and Culex pipiens pallens. This geographical dataset delivers a distribution and diversity outline of mosquito-associated viruses in China, and also applicable in various spatial and risk-assessment analysis.

Development and field evaluation of a nested RT-PCR kit for detecting Japanese encephalitis virus in mosquitoes

2011 ◽  
Vol 171 (1) ◽  
pp. 248-252 ◽  
Author(s):  
Young Eui Jeong ◽  
Min Ju Jeon ◽  
Jung Eun Cho ◽  
Myung Guk Han ◽  
Hwan Ju Choi ◽  
...  
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Field Evaluation ◽  
Encephalitis Virus ◽  
Rt Pcr

scholarly journals Molecular epidemiology of Japanese Encephalitis Virus in pig population of Odisha, Assam and Manipur states of India

2019 ◽  
Author(s):  
Ankita Datey ◽  
Leichombam Mohindro Singh ◽  
Uttam Rajkhowa ◽  
Birendra Kumar Prusty ◽  
Tanuja Saswat ◽  
...  
Keyword(s):  
Molecular Epidemiology ◽  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Human Population ◽  
Case Fatality ◽  
Encephalitis Virus ◽  
Effective Control ◽  
Single Mutation ◽  
Rt Pcr ◽  
Geographical Regions

AbstractJapanese encephalitis virus (JEV) comes under the family Flaviviridae and genus flavivirus. It predominantly infects the children under the age of 10 years and the case fatality rate can stretch out as high as 30%. Pigs act as reservoir and amplifying intermediate host for JEV. Recent report suggested longer persistence of JEV in tonsil than in circulation of experimentally infected pigs. The current investigation was conducted to understand the prevalence and molecular epidemiology of JEV infection in pigs in three different geographical sites in India (Odisha, Assam and Manipur). Serum samples were tested by ELISA and RT-PCR for detection of JEV, while only RT-PCR was done in case of tonsils tissues collected from pigs slaughtered in abattoir. Prevalence of JEV was highest in Manipur (25.45% in serum and 10.08% in tonsil) but lower in Assam (3.75% in serum and 0% in tonsils) and Odisha (1.49% in serum and 3.7% in tonsils). The percentage of sero-positivity was found to be 3.75% of IgM and 9.9% of IgG in Assam and Odisha respectively. Genotype III (GIII) of JEV was the dominant genotype and sporadic mutations of S83G, H76P, E78Q, C55S, and S64W along with two consistent mutations V46S and V51I were observed in all the GIII strains. Analysis of the E gene sequence revealed a single mutation, S118N in the GI strain. Older pigs (above 7 months) were found to be infected relatively more (8.6%) than younger pigs (age group 3-7 months). 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.Author summaryJapanese encephalitis is one of the contributing factors in acute encephalitis syndrome cases reported across India as well as Asia. Primarily young naive human population are affected with JEV. The death rate can be as high as 30% and in about 30%-50% surviving population paralysis, brain damage or other serious permanent sequelae may be observed. The viral load gets amplified in pigs and thus plays a crucial role in transmitting the infection in human communities living in close proximity to pig dwelling. The current study was conducted to demonstrate prevalence of JEV in pig population of three geographical regions of India viz. the States of Odisha, Assam and Manipur that have reported JE outbreaks in human population. The current study demonstrates that the rate of infection is 3.28% among pigs in Manipur followed by Assam and Odisha. GIII was found to be the most predominant JEV genotype, while only one GI genotype strain was detected from Odisha region. These findings suggested the need of continuous surveillance of this virus in pigs and proper implementation of human and animal vaccination programme to control the infection.

scholarly journals Sensitive and specific detection of strains of Japanese encephalitis virus using a one-step TaqMan RT-PCR technique

2004 ◽  
Vol 74 (4) ◽  
pp. 589-596 ◽  
Author(s):  
Jau-Ling Huang ◽  
Hui-Tsu Lin ◽  
Yu-Ming Wang ◽  
Ming-Hui Weng ◽  
Da-Der Ji ◽  
...  
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Encephalitis Virus ◽  
Rt Pcr ◽  
Specific Detection ◽  
One Step

scholarly journals Mosquito Vector Competence for Japanese Encephalitis Virus

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1154
Author(s):  
Heidi Auerswald ◽  
Pierre-Olivier Maquart ◽  
Véronique Chevalier ◽  
Sebastien Boyer
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Vector Competence ◽  
Mosquito Species ◽  
Encephalitis Virus ◽  
Control Measures ◽  
Local Context ◽  
Mosquito Vector ◽  
Vector Species ◽  
Local Climate

Japanese encephalitis virus (JEV) is a zoonotic pathogen mainly found in East and Southeast Asia and transmitted by mosquitoes. The objective of this review is to summarize the knowledge on the diversity of JEV mosquito vector species. Therefore, we systematically analyzed reports of JEV found in field-caught mosquitoes as well as experimental vector competence studies. Based on the investigated publications, we classified 14 species as confirmed vectors for JEV due to their documented experimental vector competence and evidence of JEV found in wild mosquitoes. Additionally, we identified 11 mosquito species, belonging to five genera, with an experimentally confirmed vector competence for JEV but lacking evidence on their JEV transmission capacity from field-caught mosquitoes. Our study highlights the diversity of confirmed and potential JEV vector species. We also emphasize the variety in the study design of vector competence investigations. To account for the diversity of the vector species and regional circumstances, JEV vector competence should be studied in the local context, using local mosquitoes with local virus strains under local climate conditions to achieve reliable data. In addition, harmonization of the design of vector competence experiments would lead to better comparable data, informing vector and disease control measures.

scholarly journals Genotype 1 Japanese encephalitis virus predominates in nature in China

2019 ◽  
Author(s):  
Nan Shao ◽  
Shihong Fu ◽  
Fan Li ◽  
Weijia Zhang ◽  
Qianying Wang ◽  
...  
Keyword(s):  
Japanese Encephalitis Virus ◽  
Real Time ◽  
Japanese Encephalitis ◽  
Mosquito Species ◽  
Encephalitis Virus ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Principal Vector ◽  
Asian Pacific Region ◽  
Asian Pacific

AbstractIntroductionJapanese encephalitis virus (JEV), in the genus Flavivirus, family Flaviviridae, is the leading cause of viral encephalitis in the Asian-Pacific region. JEV has a wide range of vector hosts, including mosquitoes, swine, and wading birds. Culex species, especially Culex tritaeniorhynchus, are the main vectors for JEV transmission. JEV has been classified into five genotypes (G1–G5). JEV G1, G3, and G5 isolates have been found in China.MethodsMore than 200,000 mosquitoes collected in 14 provinces in China from 2004 to 2016 were examined for JEV using a TaqMan real-time RT-PCR assay. The JEV envelope (E) gene was sequenced from positive pools. The nucleic acid sequences were analyzed and aligned using ClustalX ver. 2.0. Representative JEV envelope (E) gene sequences were downloaded from GenBank and compared with the newly obtained JEV sequences. MEGA 5.05 was used to generate a phylogenetic tree based on the JEV sequences.ResultsMore than 200,000 mosquitoes were divided into 3107 pools to test for JEV. Of the pools, 9.04% (281/3107) were positive. The JEV obtained from mosquitoes included three genotypes (G1, G3, and G5). JEV G1 was detected from different provinces during 2004–2016. G1 was the dominant genotype circulating in nature, comprising 98.93% (278/281). JEV G3 was detected in Yunnan and Chongqing Provinces before 2010; JEV G5 was detected only in Tibet. No pools were positive for JEV G2 and G4. C. tritaeniorhynchus was the major mosquito species and the principal vector for transmitting JEV in China. The results of the TaqMan real-time RT-PCR assay and phylogenetic analysis consistently indicated that all 50 newly identified JEV sequences belonged to JEV G1.ConclusionG1 is the main genotype of JEV circulating in nature in China. Some G3 and G5 were found, but no G2 or G4.Author summaryJapanese encephalitis virus (JEV) is a member of the genus Flavivirus, family Flaviviridae and is the major pathogen agent of Japanese encephalitis (JE) in the Asian-Pacific region. The fatality rate of JE is 20–30%. JEV consists of five genotypes (G1-G5). The predominant genotype was G3 before the 20thcentury. G1 and G3 co-circulated in China at the end of the 20thand early 21stcentury. JEV G1 is the youngest genotype and has gradually been found in many areas worldwide. Using a sensitive TaqMan real-time RT-PCR assay, this study examined 3107 pools of mosquito. The main genotype of Japanese encephalitis virus in China was G1, with some G3 and G5, but no G2 or G4. C. tritaeniorhynchus was the major mosquito species and the principal vector for transmitting JEV in China. TaqMan real-time RT-PCR assay and phylogenetic analysis consistently indicated that all 50 newly identified JEV sequences belonged to JEV G1.

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