An outbreak of Japanese encephalitis caused by genotype Ib Japanese encephalitis virus in China, 2018: A laboratory and field investigation

Wenjing Liu; Shihong Fu; Xuemin Ma; Xiaojing Chen; Dan Wu; Liwei Zhou; Qikai Yin; Fan Li; Ying He; Wenwen Lei; Yixing Li; Songtao Xu; Huaqing Wang; Zhenhai Wang; Huanyu Wang; Hong Yu; Guodong Liang

doi:10.1371/journal.pntd.0008312

An outbreak of Japanese encephalitis caused by genotype Ib Japanese encephalitis virus in China, 2018: A laboratory and field investigation

PLoS Negl Trop Dis. 2020 May 26;14(5):e0008312. doi: 10.1371/journal.pntd.0008312. eCollection 2020 May.

Authors

Wenjing Liu^{1

2

3}, Shihong Fu^{2

3}, Xuemin Ma⁴, Xiaojing Chen^{2

3

5}, Dan Wu⁶, Liwei Zhou⁴, Qikai Yin^{2

3}, Fan Li^{2

3}, Ying He^{2

3}, Wenwen Lei^{2

3}, Yixing Li⁶, Songtao Xu^{2

3}, Huaqing Wang⁶, Zhenhai Wang⁷, Huanyu Wang^{2

3}, Hong Yu¹, Guodong Liang^{2

3}

Affiliations

¹ Department of Pathogenic Biology, School of Basic Medicine, Qingdao University, Qingdao, People's Republic of China.
² Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
³ State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
⁴ Ningxia Hui Autonomous Region Center for Disease Control and Prevention, People's Republic of China.
⁵ Department of Epidemiology, School of Medicine, Jinan University, Guangzhou, People's Republic of China.
⁶ National Immunization Programme, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
⁷ Center for Neurology, General Hospital of Ningxia Medical University, Ningxia, People's Republic of China.

Abstract

Although Japanese encephalitis virus genotype Ib (JEV GIb) has replaced JEV GIII as the dominant genotype in endemic areas of Asia, no JEV GIb has been isolated from JE cases and natural mosquitoes at the same time in an outbreak of JE. In this study, we conducted virological and molecular biological laboratory tests on JE case samples (serum/cerebrospinal fluid) and locally collected mosquito samples from the 2018 JE outbreak in Ningxia, China. The result of JEV IgM antibody detection showed that 96% (67/70) of the suspected cases were laboratory-confirmed JE cases. Of the mosquitoes collected from local environments, 70% (17400/24900) were Culex tritaeniorhynchus of which 4.6% (16 /348 of the pools tested) were positive for JEV, other mosquitoes were negative. JEVs isolated from both the human cases and C. tritaeniorhynchus specimens belong to JEV GIb and are in the same evolutionary clade according to molecular evolution analyses. JEV GIb was detected simultaneously from specimens of JE cases and mosquito samples collected in nature in this study, suggesting that the JE outbreak that occurred in Ningxia in 2018 was due to infection of JEV GIb.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Antibodies, Neutralizing
Antibodies, Viral / blood
Antibodies, Viral / cerebrospinal fluid
China / epidemiology
Disease Outbreaks*
Encephalitis Virus, Japanese / classification*
Encephalitis Virus, Japanese / genetics
Encephalitis, Japanese / blood
Encephalitis, Japanese / cerebrospinal fluid
Encephalitis, Japanese / epidemiology*
Encephalitis, Japanese / virology*
Female
Genotype*
Humans
Immunoglobulin M / blood
Male
Phylogeny
West Nile Fever / epidemiology
West Nile Fever / virology
Young Adult

Substances

Antibodies, Neutralizing
Antibodies, Viral
Immunoglobulin M

Grants and funding

This work was supported by grants from the National Key Research and Development Program (2016YFD0500401)(SC,HW); the National Science and Technology Major Project of China (2018ZX10711001)(SW,HW), (2018ZX10101-002)(WW,YH);Study on etiology, pathogenic mechanism and prevention and control of epidemic Japanese encephalitis in ningxia region, key research project of ningxia science and technology in 2019(2019BCG01003)(ZW,HW);National Natural Science Foundation of China(31900156)(FL);the Development Grant of State Key Laboratory of Infectious Disease Prevention and Control (2014SKLID103)(GL)and(015SKLID505)(HW). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.