Objective: Japanese encephalitis virus infection (JEV) remains a leading cause of neurological infection in Asia, largely involving individuals living in remote areas with limited access to treatment centres and diagnostic facilities. Laboratory confirmation is fundamental for the justification and implementation of vaccination programmes. We sought to review the literature on historical developments and current diagnostic capability worldwide, to identify knowledge gaps and instil urgency to address them.
Methods: Searches were performed in Web of Science and PubMed using the text word term 'Japanese encephalitis' up to 13th October 2019. Studies reporting laboratory-confirmed symptomatic JE cases in humans were included, and data on details of diagnostic tests were extracted. A JE case was classified according to confirmatory levels (1-4), where level 1 represented the highest level of confidence.
Findings: 20,212 published JE cases were identified from 205 studies. 15,167 (75%) of these positive cases were confirmed with the lowest confidence diagnostic test (level 3 or 4, or level 4). Only 109 (53%) of the studies reported contemporaneous testing for dengue-specific antibodies.
Conclusion: A fundamental pre-requisite for the control of JE is lacking --- that of a simple and specific diagnostic procedure that can be adapted for point-of-care tests and readily used throughout JE endemic regions of the world.
Keywords: Flavivirus; Japanese encephalitis; Neurological infection; Public Health; Vaccination.
Copyright © 2020. Published by Elsevier Ltd.
Cellular Immune Responses to Live Attenuated Japanese Encephalitis (JE) Vaccine SA14-14-2 in Adults in a JE/Dengue Co-Endemic Area.PLoS Negl Trop Dis. 2017 Jan 30;11(1):e0005263. doi: 10.1371/journal.pntd.0005263. eCollection 2017 Jan. PLoS Negl Trop Dis. 2017. PMID: 28135273 Free PMC article. Clinical Trial.
Epidemiology of Japanese encephalitis in the Philippines: a systematic review.PLoS Negl Trop Dis. 2015 Mar 20;9(3):e0003630. doi: 10.1371/journal.pntd.0003630. eCollection 2015 Mar. PLoS Negl Trop Dis. 2015. PMID: 25794009 Free PMC article. Review.
Allergic reactions to Japanese encephalitis vaccine.Immunol Allergy Clin North Am. 2003 Nov;23(4):665-97. doi: 10.1016/s0889-8561(03)00102-4. Immunol Allergy Clin North Am. 2003. PMID: 14753386 Review.
Comparing the immunogenicity and safety of 3 Japanese encephalitis vaccines in Asia-Pacific area: A systematic review and meta-analysis.Hum Vaccin Immunother. 2015;11(6):1418-25. doi: 10.1080/21645515.2015.1011996. Hum Vaccin Immunother. 2015. PMID: 25915588 Free PMC article. Review.
Japanese encephalitis circulation pattern in swine of northern Vietnam and consequences for swine's vaccination recommendations.Transbound Emerg Dis. 2018 Dec;65(6):1485-1492. doi: 10.1111/tbed.12885. Epub 2018 May 8. Transbound Emerg Dis. 2018. PMID: 29740970