Abstract
Purpose of Review
Recent changes in Japanese encephalitis (JE) distribution, including its emergence in mainland Australia, call for a review of the epidemiology, diagnosis, treatment and prevention of this important disease.
Recent Findings
Climate change, urbanisation and changes in vector ecology have driven changes in JE epidemiology including expansion to new areas. Residents of and travellers to endemic areas face potential exposure risks. Surveillance gaps and diagnostic challenges lead to under-appreciation of the true disease burden. Treatment is supportive, but modern vaccines are safe and efficacious.
Summary
The recent emergence of JE in south-eastern Australia highlights its changing epidemiology and the threat this disease poses to other areas with largely naive human populations and with competent mosquito vectors and vertebrate hosts. Awareness of disease features and diagnostic approaches is critical to case detection in travellers and endemic populations, and preventive measures including vaccination should be advised for those with exposure risk.
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Introduction
Japanese encephalitis virus (JEV) is endemic throughout most of Asia and parts of the western Pacific and is the leading cause of viral encephalitis in Asia, causing an estimated 100,000 cases and 25,000 deaths per year [1•]. JEV is a zoonotic flavivirus transmitted primarily by Culex mosquitoes in an enzootic cycle involving water birds and pigs; humans are considered dead-end (incidental) hosts (Fig. 1) [2].
Prior to 2022, only sporadic reports of locally acquired human JEV infections had been reported in Australia, all in residents of Australia’s tropical far north [4,5,6•]. In 2022, an unprecedented outbreak of Japanese encephalitis (JE) occurred in Australia including the first known locally acquired human cases in temperate areas [7]. Ongoing seasonal transmission in south-eastern Australia is likely given the reporting of JE cases in two consecutive summers and ongoing La Niña weather patterns attracting waterbirds and providing conditions for increased mosquito breeding [2, 7].
This article reviews the history and epidemiology of JE in Australia and globally, the virus and vectors, the clinical features of infection, diagnostic tests and their limitations and the available options for prevention and treatment. We also discuss the implications of the changing epidemiology of this disease for clinical care and public health in Australia, including for those providing care to travellers.
The Virus and Vectors
JEV was first recovered in 1935 from an infected human in Tokyo, Japan. [8••] It is a neurotropic zoonotic flavivirus belonging to the Japanese encephalitis serogroup of viruses, which includes two other viruses endemic to Australia, namely, West Nile virus Kunjin subtype (WNV/KUNV) and Murray Valley Encephalitis Virus (MVEV) [9,10,11]. JEV includes five genotypes (GI-GV) that differ in their geographic distribution and disease [12•]. Genotypes I, II and III are the most prevalent, accounting for 98% of JEV strains isolated from 1935 to 2009, and are distributed throughout Asia [13]. Until recently, genotype IV was believed to be restricted to the Indonesia archipelago but is now documented to be circulating in Australia [6•, 14••]. Genotype V is older and more divergent than other genotypes and is rarely detected, although there have been reports regarding recent circulation in some parts of Asia [15, 16].
JEV is maintained in a natural transmission cycle between mosquitoes (primarily Culex spp.) and ardeid water birds, such as herons and egrets (reservoir hosts; Fig. 1). Feral and domestic pigs are important amplifying hosts of JEV as they have a high natural infection rate and develop high levels of viraemia [14••, 17]. Humans and horses are considered dead-end hosts as viraemia is not believed to reach levels that are infectious to mosquitoes [2]. JEV is transmitted to humans through mosquito bites. To date, there have only been rare case reports of human-to-human transmission via blood transfusion [18•] and liver transplantation. [19•] Screening of blood and organ donors is not routinely recommended [20, 21].
JEV has been isolated from over 30 mosquito species from the genera Aedes, Anopheles, Armigeres, Culex and Mansonia, although how many of these are competent vectors is unclear [22]. Culex tritaeniorhynchus, typically associated with rice production, is the primary mosquito vector in most endemic areas; its distribution is widespread across southeast Asia and extends into the Middle East, Africa, Europe and Australia [23, 24]. Many areas including the Pacific Islands, southern Europe, the United States and Africa remain receptive to JEV due to the presence of both competent mosquito vectors and vertebrate hosts [8••, 22, 25]. A case of apparent autochthonous JEV transmission has been reported in a febrile patient from Angola in Africa [26]. Culex annulirostris is considered the primary vector of JEV in Australia; however, at least six species from the subgenus Culex that are capable of vectoring JEV have been locally documented [15, 23]. All of these species are nocturnal in behaviour [27, 28].
Changing Epidemiology of JE, Including Emergence in Australia
Global Epidemiology
Epidemics of JEV (originally designated Japanese B encephalitis virus) were first described in Japan in the 1870s, with subsequent spread throughout large parts of Asia and part of the western Pacific [25, 29, 30]. Four billion people currently live in countries with endemic JEV transmission, with approximately 1.5 billion estimated to live in areas most suitable for transmission [31•]. Two distinct epidemiologic patterns of JEV are recognised: epidemic and endemic [32]. In temperate areas, such as in China, Japan, Nepal and northern India, cases typically follow a seasonal pattern with periodic large outbreaks every 2–15 years [25, 32, 33]. In tropical areas, such as southern Thailand, Indonesia and the Philippines, cases are more sporadic, but transmission is year-round, with peaks typically observed during the rainy season [25, 32]. Although JEV has historically been considered a rural disease, population growth and economic development have led to extending into new geographic areas and increased peri-urban transmission in many countries, including South Korea, China, Singapore, Taiwan and India [13, 30, 34].
The expansion of public health vaccination programs in endemic areas has led to dramatic reductions in the economic burden of human JE disease [25], with an estimated 45,000 JE cases averted in 2015 [1•]. As of 2020, 15 countries had national or subnational public health vaccination programs in JE-endemic areas, including Australia (outer Torres Strait Islands only), Malaysia (Sarawak only), Japan, Republic of Korea, Thailand, Cambodia, Lao PDR, Myanmar, Indonesia (Bali only), Philippines (three high-incidence regions), China, India (about 40–50% of districts), Nepal, Sri Lanka and Vietnam [35••]. Although JE incidence in many endemic countries is stable or declining, epidemic activity in some areas (such as India and Nepal) appears to be escalating, and the risk remains for unvaccinated individuals visiting or living in these areas due to ongoing enzootic JEV circulation [1•, 8••, 12•]. Due to diagnostic limitations and the low rate of clinical disease amongst those infected, human case surveillance data have limited ability to provide early signals of transmission; mosquito and animal surveillance are therefore important in monitoring JEV activity and informing control strategies to limit transmission [7]. Surveillance and diagnostic testing capacity vary across endemic areas, and under-reporting is likely to be substantial [36].
Japanese encephalitis (JE) has long been considered a disease of children in JE-endemic settings as immunity to JEV by natural infection is widespread by adulthood and likely lifelong in the context of natural boosting [9, 35••]. However, a shift in the epidemiology of clinical cases from children to adults, likely contributed to by childhood vaccination programs and potentially less intense transmission, has been documented in several countries, raising questions about the need for adult vaccination [35••, 37, 38]. The introduction of JEV into immunologically naive populations typically results in cases being reported across all age groups [9, 34, 39].
Epidemiology in Australia
Local transmission of JEV in Australia was first documented in April–May 1995, with a small outbreak of 3 human cases in the Torres Strait Islands in Australia’s tropical north [5]. Between 1995 and 2021, only two further locally acquired cases in the Torres Strait Islands and Cape York peninsula were recorded. In 2021, a fatal locally acquired case of JEV infection was documented in a patient from the Tiwi Islands, Northern Territory, now considered a sentinel case to the current outbreak on the basis of viral genomic data [6•]. Prior to 2022, JE vaccine recommendations in Australia were limited to laboratory workers, those living or working on the outer islands of the Torres Strait and travellers intending to spend a month or more in JE-endemic areas, leaving the population largely susceptible [40].
In early 2022, an outbreak of JEV was declared in south-eastern Australia, following the detection of JEV in stillborn and weak piglets at piggeries with subsequent detection of human cases, in keeping with a pattern documented in previous outbreaks in new geographic areas [2, 41, 42]. As of February 2023, 46 human JE cases have been reported, with 7 deaths, and the majority of cases have occurred in older adults [7]. This is the first major outbreak of JEV in mainland Australia, with cases widely distributed across five jurisdictions (Victoria, New South Wales, South Australia, Queensland and the Northern Territory) [14••, 43]. Most human cases have been acquired within the Murray-Darling Basin (a system of interconnected rivers and lakes including the Murray and Darling Rivers), which spans four affected jurisdictions in southeast Australia [7, 44]. Two recent voluntary serosurveys of NSW and Victorian residents living in the Murray-Darling Basin found evidence of exposure to JEV in 1 in 11 (80/917; 8.7%) and 1 in 30 (27/820; 3.3%) people, respectively [45, 46]. Detection of JEV in piggeries, mosquitoes and sentinel chickens, along with human JEV cases across two consecutive summer seasons in the Murray-Darling Basin may reflect the establishment of enzootic transmission [2, 7]. This outbreak has probably been driven in part by increased rainfall and flooding due to three consecutive La Niña weather events, which have attracted waterbirds and provided conditions for increased mosquito breeding [2]. Affected areas, recently mapped in another paper [7], closely mirror those of previous outbreaks of other neurotropic flaviviruses endemic to Australia associated with La Niña rainfall events (MVEV and WNV/KUNV) [14••]. Modelling studies indicate that competent vectors are widely distributed along the northern and eastern coastlines of the continent, inland regions within the Murray-Darling Basin and some areas of the southwestern coastline [44].
Epidemiology in Travellers
Previous JE risk estimates in travellers have ranged from 1 case per 400,000 trips to < 1 case per million trips to an endemic area [25]. Although these estimates suggest the risk of travel-related acquisition is low overall, it is important to note that these figures are based on clinical infections and are likely to substantially underestimate risk due to under-reporting and the frequency of mild or sub-clinical infections [25, 30]. Individual traveller risk is highly variable (depending on the traveller’s activities, season, location and duration of travel), and severe outcomes in travellers have been reported [25, 47]. A 1973–2008 case series of 55 published cases in travellers from non-endemic areas identified cases in travellers of all ages (range 1–91 years) and included cases resulting in death or severe sequelae [48]. While, historically, many travel-related cases occurred in military personnel [29], increased tourism to South-East Asia in past decades has led to more cases being identified amongst tourist travellers, with the most common countries of acquisition being Thailand and Indonesia [48, 49].
Published cases of travellers from non-endemic areas since 2008 are summarised in Table 1. Of these 21 cases, almost half (10/21; 48%) were in short-term (< 1 month) travellers, 5 (24%) were fatal, and 10 (48%) resulted in long-term sequelae, confirming the devastating consequences of JE from previous reports. Thailand (8/21; 38%) and Indonesia (4/21; 19%) remained the most common countries of acquisition for travellers.
Clinical Manifestations and Consequences
Most JEV infections are asymptomatic, with less than 1% of infections overall progressing to encephalitis [65,66,67,68]. However, the risk of clinical disease varies with age at first exposure, and for adults from non-endemic countries, it can be as high as 1 in 25 [25]. Reported outcomes vary widely, but recent reviews estimate the case fatality rate of reported JE cases to be 14–21%, with almost 50% of survivors having persistent neurological deficits at 1-year post hospital discharge [69••, 70].
Symptoms typically occur after an incubation period of 5–15 days (average 7 days) [71]. Neurologic symptoms typically follow a short, non-specific febrile prodrome [9]. Amongst symptomatic cases, the most commonly identified clinical syndrome is acute encephalitis, characterised by decreased or altered level of consciousness, headache, vomiting and often seizures (particularly amongst children) [70].Focal neurological signs are variable and reflect anatomical sites of involvement. Parkinsonian features, including mask-like facies, tremors and cogwheel rigidity reflect basal ganglia involvement and typically appear 1–4 weeks after illness onset [70,72,73]. Poliomyelitis-like flaccid paralysis reflects spinal cord involvement [63]. Cranial nerve signs include facial palsies, ptosis and abnormal eye movements. Ocular manifestations are rare, but chorioretinitis has been reported [62]. JEV has occasionally been associated with Guillain–Barre syndrome, as has been reported with other flaviviruses such as the Zika virus [74]. Although JEV is not usually considered to cause congenital infection, this may be because of high seropositivity rates among women of childbearing age in endemic countries [75]. Limited case reports suggesting potential for transplacental infection and adverse pregnancy outcomes, indicating that the risks of JEV infection in immune-naïve pregnant women, need better elucidation [75, 76].
During acute illness, abnormalities of routine peripheral blood tests are non-specific, with common findings including neutrophilia and sometimes hyponatremia [70]. Analysis of cerebrospinal fluid (CSF) typically shows a mild to moderate pleocytosis with a lymphocytic predominance, slightly elevated protein and a normal ratio of CSF-to-plasma glucose.
Diagnostic Challenges
Preliminary diagnosis relies on the individual’s clinical presentation and thorough exposure history, including recent travel and outdoor activities [77]. Clinical features may overlap with those of other neurotropic flaviviruses, including those that are endemic to Australia (see Table 2) [70, 72].
In patients presenting with a suspected flavivirus encephalitis, the diagnostic work-up should include cerebrospinal fluid (CSF) sampling and neuroimaging [77]. Where available, magnetic resonance imaging (MRI) is the preferred imaging modality as it provides better soft tissue contrast than computed tomography (CT); T2 and T2-FLAIR MRI sequences are considered most useful [83••, 84]. Thalamic lesions are the most common focal MRI finding in JE, occurring in around 74% of those presenting with encephalitis; however, such lesions are also described in encephalitis due to other flaviviruses (including dengue, MVEV and WNV/KUNV) and herpesviruses (e.g. Herpes Simplex Virus-1) and are, therefore, not pathognomonic [10, 78, 83••, 85, 86]. Basal ganglia and hippocampus lesions are reported much more frequently in JE than in dengue encephalitis and may be a more useful diagnostic clue in settings where these infections co-exist [83••].
Detection of JEV RNA in whole blood, CSF, urine or brain tissue by nucleic acid amplification testing (NAAT) confirms the diagnosis; prolonged JEV RNA detection out to 26 days in urine and 28 days in whole blood has been reported [59]. However, due to the typically low level and short duration of viraemia that occur in human JEV infection and the neurotropism of the virus, detection of JEV from clinical specimens is often unsuccessful [87••, 88]. Recent laboratory data from one Australian jurisdiction exemplify the low sensitivity of NAAT and the critical role of serology [43]. Viral culture is also diagnostic and may be attempted from CSF, whole blood, urine or brain tissue, but is time and resource intensive and requires a biosafety level 3 laboratory. [87••]. Metagenomic next-generation sequencing is a promising tool for cases of unexplained encephalitis where targeted investigations fail to yield a diagnosis and has assisted in recognising at least one unsuspected JEV infection in the current Australian outbreak, but largely remains a research tool in well-resourced settings [43, 87••].
Serology remains the cornerstone of diagnosis for JEV, but testing and interpretation are complex and require knowledge of patient demographics, the timing of potential exposure, and any prior vaccination against or infection with other flaviviruses [87••]. Australian guidelines promote universal pan-flavivirus serology in patients presenting with encephalitis in Australia, but uptake is generally low [89, 90]. The diagnostic criteria used to confirm JEV infection in the Australian setting have recently been revised [91]. Detection of anti-JEV IgM in CSF is generally considered to confirm the diagnosis of JE, with a sensitivity and specificity of > 95% by day 10 of illness, but the capacity for CSF collection may be limited in rural areas where cases often occur [35••, 87••]. Additionally, alternative diagnoses including dengue, tuberculosis and rickettsial infections have been identified through PCR or pathogen isolation in some patients with detectable anti-IgM in CSF in endemic settings [92]. Serum anti-JEV IgM has the greatest sensitivity in early illness (75% of patients have anti-JEV IgM by day 4 after illness onset), but results can be difficult to interpret in areas with other co-circulating flaviviruses due to cross-reactivity [87••, 93]. Additionally, anti-JEV IgM can persist for 30–90 days (or even longer) following acute infection and for one month or more following JEV vaccination, and therefore its detection may occasionally reflect recent infection or vaccination rather than acute infection [35••, 87••]. Anti-JEV IgG is detectable in serum and/or CSF in about 80% of patients by day 7 post illness onset and peaks around day 30 [87••]. The timing of testing in relation to clinical illness is an important consideration, and where possible, serology should be performed at presentation and repeated on day 10 of illness to assess for seroconversion or a four-fold or greater rise in antibody titres [90].
Treatment
Treatment focuses on supportive care, as no specific treatment options are currently available, although in endemic countries, optimising supportive care does improve outcomes [94, 95]. Previous double-blind, placebo-controlled, randomised clinical trials of dexamethasone, interferon alpha 2a, ribavirin, intravenous immunoglobulin (IVIG) and minocycline in patients with JE did not demonstrate detectable benefits on any clinical outcome measure, but the sample size may have been too small [70]. Pre-clinical studies have highlighted a number of compounds that are potentially suitable for treatment, but pragmatic human trials are needed [70, 96]. Given the evidence that JE pathogenesis is driven by both direct viral and immune-mediated effects, future trials should consider a combination of both anti-viral and immune-modulatory treatments [70].
Prevention
JE vaccines have been available for decades, but their introduction and uptake have been limited by high cost and (in some cases) multiple-dose regimens [35••]. Efficacy and safety concerns related to early inactivated mouse brain-derived vaccines have largely led to their replacement with three newer generation vaccine classes: inactivated Vero cell-derived, live attenuated (i.e. CD-JEV) and live recombinant (chimeric) vaccines (i.e. JE-CV), all of which are safe and immunogenic [97, 98••]. All licensed vaccine viruses are genotype III JEV but have been found to elicit protective levels of neutralising antibodies against genotypes I-IV [99]. Neutralising antibody data and differences between genotype V and III viruses suggest that current vaccines may not be as efficacious against genotype V virus [35••]. The World Health Organisation recommends the integration of JE vaccines into national immunisation schedules in all areas where JE is recognised as a public health priority [100]. Most current country-supported JE immunisation programs (including China and India) use CD-JEV; four use JE-CV (Australia, Malaysia, Thailand, Taiwan), three use Vero cell vaccines (Japan, South Korea and Taiwan); and one (Vietnam) continues to use mouse brain-derived vaccines but has plans to scale-up local production of an inactivated Vero cell-derived vaccine for broader use [35••, 101]. JE vaccine availability in non-endemic areas varies; the only vaccine available in Europe and North America is the inactivated Vero cell-derived vaccine IXIARO® (Valneva) [102].
Two JE vaccines are currently licensed and available in Australia: the live recombinant vaccine Imojev® (Sanofi Pasteur), licensed from 9 months of age; and the inactivated Vero cell-derived vaccine JEspect® (Valneva; marketed in other countries as Ixiaro®), licensed from 2 months of age [39, 103]. Both are well-tolerated, and their efficacy is comparable, but they differ in cost and the number of doses required [40, 98••]. The recommended primary schedule for JEspect® is two doses, given 28 days apart, whereas for Imojev®, it is a single dose. In Australia, a booster dose is recommended for those at ongoing risk of JE virus exposure if more than 1 year has passed since the primary schedule, regardless of which vaccine was received, except in people who received a dose of Imojev as an adult (≥ 18 years), where a booster dose is not required [104]. As no studies have examined the interchangeability of JEspect® and Imojev®, it is preferable to use the same vaccine for booster doses as was used for the primary course [104]. Provision of a booster dose of a newer generation class vaccine (e.g. JEspect® or Imojev®) to someone previously vaccinated with a mouse brain-derived vaccine has been shown to be effective and safe [105••]. Current data are insufficient to inform recommendations regarding the need for or timing of further booster doses in those at long-term, ongoing risk. Pooled seropositivity rates following a primary schedule plus booster dose (where indicated) are above 95% and appear to remain stable for up to 6 years [105••]. Imojev® is contraindicated in pregnant women and people who are immunocompromised [104]. Pregnant women at risk of acquiring JE are recommended to receive JEspect® [103]. No data on the safety or efficacy of JEspect® in immunocompromised persons are available [106]. As an inactivated vaccine, JEspect® is not expected to cause any safety concerns in immunocompromised persons, but vaccine responses may be diminished in this population [103, 106].
In Australia, constraints to vaccine supply have influenced the public health rollout of JE vaccination, with funded vaccine eligibility generally limited to people with relevant occupational risk and those who live or routinely work in affected areas and are regularly outdoors for long periods [7]. As vaccination campaigns with live recombinant JE vaccine may result in the unintentional vaccination of people with a contraindication or precaution to vaccination, such as pregnant women, ongoing post-marketing vaccine surveillance remains important. There is growing interest in the use of intradermal (ID) administration of live recombinant JE vaccine as a dose-sparing strategy, but comparative vaccine effectiveness and immunogenicity data are needed [107•, 108, 109]. Further studies are planned, including in Australia (see https://www.ncirs.org.au/clinical-research/japanese-encephalitis-vaccine-study).
JE vaccine guidance for travellers generally recommends vaccination for those spending a month or more in risk areas during the transmission season and suggests consideration of vaccination for those undertaking shorter-term travel with additional risk factors or those undertaking multiple short trips which cumulatively result in the potential for more than 4 weeks at risk [84, 87••, 90]. Currently, the vaccine is underutilised among travellers, with most travellers to endemic areas not receiving a vaccination, even if pre-travel advice is sought [30, 110, 111]. Given the unpredictable epidemiology of JE, its propensity to cause severe disease and death, expansion to new geographic areas, and recent reports of JE in short-term travellers (reported travel duration < 1 month for 10/21 published cases from 2008 to 2022; Table 1), there is a compelling case to consider more widespread vaccination, including in travellers [35••, 47].
Another key preventive strategy for those living in or visiting endemic areas is mosquito bite avoidance. Mosquitoes that transmit JEV are nocturnal in behaviour and the greatest risk period for bites is between dusk and dawn [22, 30]. Strategies to avoid bites include the use of insect repellents, wearing protective clothing (such as long-sleeved shirts and pants), treating clothing and gear with an insecticide such as permethrin, and sleeping in screened or air-conditioned rooms or under an insecticide-impregnated bed net [112-113].
Conclusion
JEV remains an important health threat in Asia and the Western Pacific, with significant morbidity and mortality. Experience from recent decades indicates that outbreaks are unpredictable, as has been exemplified in Australia, and are likely to continue to occur as urban growth, globalisation and climate change continue. Mosquito and animal surveillance is important since human case surveillance data may not provide early signals of transmission. Clinical features may overlap with those of other flaviviruses, and the interpretation of serology may be challenging. Treatment is supportive, as no treatment options with proven efficacy are available, and more highly powered clinical trials combining virus-directed and immune response-directed treatments are needed. Modern vaccines are safe and effective. Clinicians seeing those at risk, including in the pre-travel setting, should maintain best practice approaches around risk communication and give advice on insect bite precautions as well as vaccination based on individualised risk assessment.
Data Availability
All data generated or analysed during this study are included in this published article.
References
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance
• Quan TM, Thao TTN, Duy NM, Nhat TM, Clapham H. Estimates of the global burden of Japanese encephalitis and the impact of vaccination from 2000–2015. eLife. 2020;9:e51027. Mathematical modelling study estimating the global JE burden and impact of vaccination from 2000-2015 using methods to overcome some of the limitations of existing JE surveillance.
Mackenzie JS, Williams DT. Japanese encephalitis virus: an emerging and re-emerging virus in Australia. Microbiology Australia. 2022;43(4):150–5.
Mulvey P, Duong V, Boyer S, Burgess G, Williams DT, Dussart P, et al. The ecology and evolution of Japanese encephalitis virus. Pathogens. 2021;10(12):1534.
Hanna JN, Ritchie SA, Phillips DA, Lee JM, Hills SL, van den Hurk AF, et al. Japanese encephalitis in north Queensland, Australia, 1998. Med J Aust. 1999;170(11):533–6.
Hanna JN, Ritchie SA, Phillips DA, Shield J, Bailey MC, Mackenzie JS, et al. An outbreak of Japanese encephalitis in the Torres Strait, Australia, 1995. Med J Aust. 1996;165(5):256–60.
• Waller C, Tiemensma M, Currie BJ, Williams DT, Baird RW, Krause VL. Japanese encephalitis in Australia - a sentinel case. N Engl J Med. 2022;387(7):661–2. Case report of fatal JE case in a Northern Territory resident in February 2021, identified as a sentinel case to the current Australian outbreak on the basis of viral genomic data.
McGuinness SL, Lau CL, Leder K. The evolving Japanese encephalitis situation in Australia and implications for travel medicine. J Travel Med. 2023.
•• Pierson TC, Diamond MS. The continued threat of emerging flaviviruses. Nat Microbiol. 2020;5(6):796–812. Recent review of globally important flaviviruses, including JEV, with maps of their global distribution.
Solomon T. Flavivirus encephalitis. N Engl J Med. 2004;351(4):370–8.
Gray TJ, Burrow JN, Markey PG, Whelan PI, Jackson J, Smith DW, et al. West Nile virus (Kunjin subtype) disease in the northern territory of Australia–a case of encephalitis and review of all reported cases. Am J Trop Med Hyg. 2011;85(5):952–6.
Musso D, Rodriguez-Morales AJ, Levi JE, Cao-Lormeau VM, Gubler DJ. Unexpected outbreaks of arbovirus infections: lessons learned from the Pacific and tropical America. Lancet Infect Dis. 2018;18(11):e355–61.
• Kuwata R, Torii S, Shimoda H, Supriyono S, Phichitraslip T, Prasertsincharoen N, et al. Distribution of Japanese encephalitis virus, Japan and Southeast Asia, 2016–2018. Emerg Infect Dis. 2020;26(1):125–8. Surveillance study of pigs and mosquitoes in Japan, Thailand, the Philippines and Indonesia demonstrating indigenous maintenance of enzootic JEV transmission cycles in these settings.
Le Flohic G, Porphyre V, Barbazan P, Gonzalez J-P. Review of climate, landscape, and viral genetics as drivers of the Japanese encephalitis virus ecology. PLoS Negl Trop Dis. 2013;7(9): e2208.
•• Mackenzie JS, Williams DT, van den Hurk AF, Smith DW, Currie BJ. Japanese encephalitis virus: the emergence of genotype IV in Australia and its potential endemicity. Viruses. 2022;14(11). Overview of the emergence of JEV Genotype IV in Australia and the relevance of this virgin soil outbreak to the possible threat JEV may pose to other potentially JEV-receptive areas.
Gao X, Liu H, Li M, Fu S, Liang G. Insights into the evolutionary history of Japanese encephalitis virus (JEV) based on whole-genome sequences comprising the five genotypes. Virol J. 2015;12:43.
Lee AR, Song JM, Seo SU. Emerging Japanese encephalitis virus genotype V in Republic of Korea. J Microbiol Biotechnol. 2022;32(8):955–9.
Ladreyt H, Durand B, Dussart P, Chevalier V. How central is the domestic pig in the epidemiological cycle of Japanese encephalitis virus? A Review of Scientific Evidence and Implications for Disease Control. Viruses. 2019;11(10).
• Cheng VCC, Sridhar S, Wong SC, Wong SCY, Chan JFW, Yip CCY, et al. Japanese encephalitis virus transmitted via blood transfusion, Hong Kong, China. Emerg Infect Dis. 2018;24(1):49–57. Case report of transfusion-transmitted JEV, demonstrating that JEV can be transmitted via blood products.
• Qi ZL, Sun LY, Bai J, Zhuang HZ, Duan ML. Japanese encephalitis following liver transplantation: a rare case report. World J Clin Cases. 2020;8(2):337–42. Case report of human-to-human JEV transmission via organ transplantation.
Hoad VC, Kiely P, Seed CR, Viennet E, Gosbell IB. An outbreak of Japanese encephalitis virus in Australia; what is the risk to blood safety? Viruses. 2022;14(9).
Bansal SB, Ramasubramanian V, Prasad N, Saraf N, Soman R, Makharia G, et al. South Asian Transplant infectious disease guidelines for solid organ transplant candidates, recipients, and donors. Transplantation. 2023.
Pearce JC, Learoyd TP, Langendorf BJ, Logan JG. Japanese encephalitis: the vectors, ecology and potential for expansion. J Travel Med. 2018;25(suppl_1):S16-S26.
Lessard BD, Kurucz N, Rodriguez J, Carter J, Hardy CM. Detection of the Japanese encephalitis vector mosquito Culex tritaeniorhynchus in Australia using molecular diagnostics and morphology. Parasit Vectors. 2021;14(1):411.
Longbottom J, Browne AJ, Pigott DM, Sinka ME, Golding N, Hay SI, et al. Mapping the spatial distribution of the Japanese encephalitis vector, Culex tritaeniorhynchus Giles, 1901 (Diptera: Culicidae) within areas of Japanese encephalitis risk. Parasit Vectors. 2017;10(1):148.
Lindquist L. Recent and historical trends in the epidemiology of Japanese encephalitis and its implication for risk assessment in travellers. J Travel Med. 2018;25(suppl_1):S3-S9.
Simon-Loriere E, Faye O, Prot M, Casademont I, Fall G, Fernandez-Garcia MD, et al. Autochthonous Japanese encephalitis with yellow fever coinfection in Africa. N Engl J Med. 2017;376(15):1483–5.
Rohani A, Zamree I, Wan Mohamad Ali W, Abdul Hadi A, Asmad M, Lubim D, et al. Nocturnal man biting habits of mosquito species in Serian, Sarawak, Malaysia. Adv Entomol. 2013;1:42–29.
Van Den Hurk AF, Johansen CA, Zborowski P, Paru R, Foley PN, Beebe NW, et al. Mosquito host-feeding patterns and implications for Japanese encephalitis virus transmission in northern Australia and Papua New Guinea. Med Vet Entomol. 2003;17(4):403–11.
Gatus BJ, Rose MR. Japanese B encephalitis: epidemiological, clinical and pathological aspects. J Infect. 1983;6(3):213–8.
Connor B, Bunn WB. The changing epidemiology of Japanese encephalitis and new data: the implications for new recommendations for Japanese encephalitis vaccine. Trop Dis Travel Med Vaccines. 2017;3(1):14.
• Moore SM. The current burden of Japanese encephalitis and the estimated impacts of vaccination: combining estimates of the spatial distribution and transmission intensity of a zoonotic pathogen. PLoS Negl Trop Dis. 2021;15(10):e0009385. Mathematical modelling study estimating the global JE burden and impact of vaccination from 2010-2019 and identifying the countries that could benefit the most from the introduction or expansion of vaccination coverage.
Erlanger TE, Weiss S, Keiser J, Utzinger J, Wiedenmayer K. Past, present, and future of Japanese encephalitis. Emerg Infect Dis. 2009;15(1):1–7.
Kumari R, Joshi PL. A review of Japanese encephalitis in Uttar Pradesh, India. WHO South East Asia J Public Health. 2012;1(4):374–95.
Kumari R, Kumar K, Rawat A, Singh G, Yadav NK, Chauhan LS. First indigenous transmission of Japanese encephalitis in urban areas of national capital territory of Delhi. India Trop Med Int Health. 2013;18(6):743–9.
•• Vannice KS, Hills SL, Schwartz LM, Barrett AD, Heffelfinger J, Hombach J, et al. The future of Japanese encephalitis vaccination: expert recommendations for achieving and maintaining optimal JE control. npj Vaccines. 2021;6(1):82. Narrative review of the current state of JE vaccines, surveillance and control globally, including a summary of key discussion points and recommendations to sustain and expand JE control from an international meeting of independent experts in 2018.
Heffelfinger JD, Li X, Batmunkh N, Grabovac V, Diorditsa S, Liyanage JB, et al. Japanese Encephalitis surveillance and immunization - Asia and Western Pacific Regions, 2016. MMWR Morb Mortal Wkly Rep. 2017;66(22):579–83.
Hu XT, Li QF, Ma C, Zhao ZX, He LF, Tang TT, et al. Reduction patterns of Japanese encephalitis incidence following vaccine introduction into long-term expanded program on immunization in Yunnan Province, China. Infect Dis Poverty. 2019;8(1):102.
Sunwoo JS, Lee ST, Jung KH, Park KI, Moon J, Jung KY, et al. Clinical characteristics of severe Japanese encephalitis: a case series from South Korea. Am J Trop Med Hyg. 2017;97(2):369–75.
Hills SL, Netravathi M, Solomon T. Japanese encephalitis among adults: a review. Am J TropMed Hyg. 2023;108(5):860–4.
Islam N, Lau C, Leeb A, Mills D, Furuya-Kanamori L. Safety profile comparison of chimeric live attenuated and Vero cell-derived inactivated Japanese encephalitis vaccines through an active surveillance system in Australia. Hum Vaccin Immunother. 2022;18(1):2020573.
Vaughn DW, Hoke CH Jr. The epidemiology of Japanese encephalitis: prospects for prevention. Epidemiol Rev. 1992;14:197–221.
Furuya-Kanamori L, Gyawali N, Mills DJ, Hugo LE, Devine GJ, Lau CL. The emergence of Japanese encephalitis in Australia and the implications for a vaccination strategy. Trop Med Infect Dis. 2022;7(6).
Howard-Jones AR, Pham D, Jeoffreys N, Eden JS, Hueston L, Kesson AM, et al. Emerging genotype IV Japanese encephalitis virus outbreak in New South Wales, Australia. Viruses. 2022;14(9).
Furlong M, Adamu AM, Hoskins A, Russell TL, Gummow B, Golchin M, et al. Japanese encephalitis enzootic and epidemic risks across Australia. Viruses. 2023;15(2).
New South Wales Health. Summary of NSW Japanese encephalitis virus serosurvey results. 2022. Available from https://www.health.nsw.gov.au/Infectious/factsheets/Pages/jev-serology.aspx (Accessed 24 Jan 2023).
Victorian Department of Health. Serosurvey for Japanese encephalitis in northern Victoria. 2023. Available from https://www.health.vic.gov.au/infectious-diseases/serosurvey-for-japanese-encephalitis-in-northern-victoria (Accessed 10 Mar 2023).
Connor BA, Hamer DH, Kozarsky P, Jong E, Halstead SB, Keystone J, et al. Japanese encephalitis vaccine for travelers: risk-benefit reconsidered. J Travel Med. 2019;26(5).
Hills SL, Griggs AC, Fischer M. Japanese encephalitis in travelers from non-endemic countries, 1973–2008. Am J Trop Med Hyg. 2010;82(5):930–6.
Buhl MR, Lindquist L. Japanese encephalitis in travelers: review of cases and seasonal risk. J Travel Med. 2009;16(3):217–9.
Centers for Disease Control & Prevention. Japanese encephalitis in two children–United States, 2010. MMWR Morb Mortal Wkly Rep. 2011;60(9):276–8.
Hills SL, Stoltey J, Martinez D, Kim PY, Sheriff H, Zangeneh A, et al. A case series of three US adults with Japanese encephalitis, 2010–2012. J Travel Med. 2014;21(5):310–3.
Langevin S, Libman M, Drebot MA, Laverdiere M. A case of Japanese encephalitis virus infection acquired during a trip in Thailand. J Travel Med. 2012;19(2):127–9.
Werlinrud AM, Christiansen CB, Koch A. Japanese encephalitis in a Danish short-term traveler to Cambodia. J Travel Med. 2011;18(6):411–3.
Tappe D, Nemecek A, Zipp F, Emmerich P, Gabriel M, Gunther S, et al. Two laboratory-confirmed cases of Japanese encephalitis imported to Germany by travelers returning from Southeast Asia. J Clin Virol. 2012;54(3):282–5.
Lagarde S, Lagier JC, Charrel R, Querat G, Vanhomwegen J, Despres P, et al. Japanese encephalitis in a French traveler to Nepal. J Neurovirol. 2014;20(1):99–102.
Doti P, Castro P, Martinez MJ, Zboromyrska Y, Aldasoro E, Inciarte A, et al. A case of Japanese encephalitis in a 20 year-old Spanish sportsman, February 2013. Euro Surveill. 2013;18(35):20573.
Turtle L, Easton A, Defres S, Ellul M, Bovill B, Hoyle J, et al. More than devastating- patient experiences and neurological sequelae of Japanese encephalitis. J Travel Med. 2019;26(7).
Schwermer B, Eschle D, Bloch-Infanger C. Fever and headache after a vacation in Thailand. Dtsch Med Wochenschr. 2017;142(14):1063–6.
Huang GKL, Tio SY, Caly L, Nicholson S, Thevarajan I, Papadakis G, et al. Prolonged detection of Japanese encephalitis virus in urine and whole blood in a returned short-term traveler. Open Forum Infect Dis. 2017;4(4):ofx203.
Huits R, Eelen Y, Jorens PG, Arien KK, Van Esbroeck M, Duval EL. Japanese encephalitis in a young traveler returning from a short-term holiday in Khao Lak. Thailand Travel Med Infect Dis. 2020;34: 101580.
Pyke AT, Choong K, Moore F, Schlebusch S, Taylor C, Hewitson G, et al. A case of Japanese encephalitis with a fatal outcome in an Australian who traveled from Bali in 2019. Trop Med Infect Dis. 2020;5(3).
Van K, Korman TM, Nicholson S, Troutbeck R, Lister DM, Woolley I. Case report: Japanese encephalitis associated with chorioretinitis after short-term travel to Bali. Indonesia Am J Trop Med Hyg. 2020;103(4):1691–3.
Grewe S, Gliem M, Abrar DB, Feldt T, Wojtecki L, Tan V, et al. Myelitis with flaccid paralysis due to Japanese encephalitis: case report and review of the literature. Infection. 2022;50(6):1597–603.
Janatpour ZC, Boatwright MA, Yousif SM, Bonilla MF, Fitzpatrick KA, Hills SL, et al. Japanese encephalitis in a U.S. traveler returning from Vietnam, 2022. Trav Med Infect Dis. 2023;52:102536.
Benenson MW, Top FH Jr, Gresso W, Ames CW, Altstatt LB. The virulence to man of Japanese encephalitis virus in Thailand. Am J Trop Med Hyg. 1975;24(6 Pt 1):974–80.
Halstead SB, Grosz CR. Subclinical Japanese encephalitis. I. Infection of Americans with limited residence in Korea. Am J Hyg. 1962;75:190–201.
Grossman RA, Edelman R, Willhight M, Pantuwatana S, Udomsakdi S. Study of Japanese encephalitis virus in Chiangmai Valley, Thailand. 3. Human seroepidemiology and inapparent infections. Am J Epidemiol. 1973;98(2):133–49.
Gajanana A, Thenmozhi V, Samuel PP, Reuben R. A community-based study of subclinical flavivirus infections in children in an area of Tamil Nadu, India, where Japanese encephalitis is endemic. Bull World Health Organ. 1995;73(2):237–44.
•• Cheng Y, Tran Minh N, Tran Minh Q, Khandelwal S, Clapham HE. Estimates of Japanese Encephalitis mortality and morbidity: a systematic review and modeling analysis. PLoS Negl Trop Dis. 2022;16(5):e0010361. Systematic review collating age-stratified JE morbidity and mortality data and estimating changes in case fatality rates (of reported cases) over time, including differences between countries.
Turtle L, Solomon T. Japanese encephalitis - the prospects for new treatments. Nat Rev Neurol. 2018;14(5):298–313.
Rudolph KE, Lessler J, Moloney RM, Kmush B, Cummings DA. Incubation periods of mosquito-borne viral infections: a systematic review. Am J Trop Med Hyg. 2014;90(5):882–91.
Misra UK, Kalita J. Prognosis of Japanese encephalitis patients with dystonia compared to those with parkinsonian features only. Postgrad Med J. 2002;78(918):238–41.
Misra UK, Kalita J. Movement disorders in Japanese encephalitis. J Neurol. 1997;244(5):299–303.
Cao-Lormeau VM, Blake A, Mons S, Lastere S, Roche C, Vanhomwegen J, et al. Guillain-Barre syndrome outbreak associated with Zika virus infection in French Polynesia: a case-control study. Lancet. 2016;387(10027):1531–9.
Howard-Jones AR, Pham D, Sparks R, Maddocks S, Dwyer DE, Kok J, et al. Arthropod-borne flaviviruses in pregnancy. Microorganisms. 2023;11(2).
Tsai TF. Congenital arboviral infections: something new, something old. Pediatrics. 2006;117(3):936–9.
Britton PN, Eastwood K, Paterson B, Durrheim DN, Dale RC, Cheng AC, et al. Consensus guidelines for the investigation and management of encephalitis in adults and children in Australia and New Zealand. Intern Med J. 2015;45(5):563–76.
Knox J, Cowan RU, Doyle JS, Ligtermoet MK, Archer JS, Burrow JN, et al. Murray Valley encephalitis: a review of clinical features, diagnosis and treatment. Med J Aust. 2012;196(5):322–6.
Russell RC, Dwyer DE. Arboviruses associated with human disease in Australia. Microbes Infect. 2000;2(14):1693–704.
Prow NA. The changing epidemiology of Kunjin virus in Australia. Int J Environ Res Public Health. 2013;10(12):6255–72.
Hall RA, Broom AK, Smith DW, Mackenzie JS. The ecology and epidemiology of Kunjin Virus. In: Mackenzie JS, Barrett ADT, Deubel V, editors. Japanese Encephalitis and West Nile Viruses. Berlin, Heidelberg: Springer Berlin Heidelberg. 2002;253–69.
Griffiths MJ, Turtle L, Solomon T. Chapter 26 - Japanese encephalitis virus infection. In: Tselis AC, Booss J, editors. Handbook of Clinical Neurology. 123: Elsevier. 2014;561–76.
•• Pichl T, Wedderburn CJ, Hoskote C, Turtle L, Bharucha T. A systematic review of brain imaging findings in neurological infection with Japanese encephalitis virus compared with Dengue virus. Int J Infect Dis. 2022;119:102–10. Systematic review of neuroimaging findings in patients with JE (24 studies) and dengue encephalitis (68 studies).
Misra UK, Kalita J, Phadke RV, Wadwekar V, Boruah DK, Srivastava A, et al. Usefulness of various MRI sequences in the diagnosis of viral encephalitis. Acta Trop. 2010;116(3):206–11.
Floridis J, McGuinness SL, Kurucz N, Burrow JN, Baird R, Francis JR. Murray Valley encephalitis virus: an ongoing cause of encephalitis in Australia's North. Trop Med Infect Dis. 2018;3(2).
Beattie GC, Glaser CA, Sheriff H, Messenger S, Preas CP, Shahkarami M, et al. Encephalitis with thalamic and basal ganglia abnormalities: etiologies, neuroimaging, and potential role of respiratory viruses. Clin Infect Dis. 2013;56(6):825–32.
•• Pham D, Howard-Jones AR, Hueston L, Jeoffreys N, Doggett S, Rockett RJ, et al. Emergence of Japanese encephalitis in Australia: a diagnostic perspective. Pathology. 2022;54(6):669–77. Detailed review of currently available methods of JEV diagnosis, along with their relative advantages and disadvantages and their value in clinical and public health contexts.
Bharucha T, Shearer FM, Vongsouvath M, Mayxay M, de Lamballerie X, Newton PN, et al. A need to raise the bar - a systematic review of temporal trends in diagnostics for Japanese encephalitis virus infection, and perspectives for future research. Int J Infect Dis. 2020;95:444–56.
Britton PN, Eastwood K, Brew BJ, Nagree Y, Jones CA. Consensus guidelines for the investigation and management of encephalitis. Med J Aust. 2015;202(11):576–7.
Allen S, Cooper C, Traranath A, Cheng AC, Britton PN. Japanese encephalitis virus: changing the clinical landscape of encephalitis in Australia. Med J Aust. 2023;218(8):344-47.
Communicable Diseases Network of Australia (CDNA). Japanese encephalitis virus infection - surveillance case definition version 2.0. 2023. Available from: https://www.health.gov.au/resources/collections/cdna-surveillance-case-definitions (Accessed 14 Mar 2023).
Dubot-Peres A, Sengvilaipaseuth O, Chanthongthip A, Newton PN, de Lamballerie X. How many patients with anti-JEV IgM in cerebrospinal fluid really have Japanese encephalitis? Lancet Infect Dis. 2015;15(12):1376–7.
Moore CE, Blacksell SD, Taojaikong T, Jarman RG, Gibbons RV, Lee SJ, et al. A prospective assessment of the accuracy of commercial IgM ELISAs in diagnosis of Japanese encephalitis virus infections in patients with suspected central nervous system infections in Laos. Am J Trop Med Hyg. 2012;87(1):171–8.
Chong HY, Leow CY, Abdul Majeed AB, Leow CH. Flavivirus infection-a review of immunopathogenesis, immunological response, and immunodiagnosis. Virus Res. 2019;274: 197770.
Pinapati KK, Tandon R, Tripathi P, Srivastava N. Recent advances to overcome the burden of Japanese encephalitis: a zoonotic infection with problematic early detection. Rev Med Virol. 2023;33(1): e2383.
Joe S, Salam AAA, Neogi U, Mudgal PP. Antiviral drug research for Japanese encephalitis: an updated review. Pharmacol Rep. 2022;74(2):273–96.
Halstead SB, Thomas SJ. Japanese encephalitis: new options for active immunization. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 2010;50(8):1155–64.
•• Furuya-Kanamori L, Xu C, Doi SAR, Clark J, Wangdi K, Mills DJ, et al. Comparison of immunogenicity and safety of licensed Japanese encephalitis vaccines: a systematic review and network meta-analysis. Vaccine. 2021;39(32):4429–36. Systematic review and meta-analysis comparing immunogenicity and safety of licensed JE vaccines.
Erra EO, Askling HH, Yoksan S, Rombo L, Riutta J, Vene S, et al. Cross-protective capacity of Japanese encephalitis (JE) vaccines against circulating heterologous JE virus genotypes. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 2013;56(2):267–70.
Japanese encephalitis vaccines. WHO position paper - February 2015. Wkly Epidemiol Rec. 2015;90(9):69–87.
Lien HP, Thiem VD, Dat DT, Tuan NA, Thu NT, Quang ND, et al. Safety and immunogenicity of inactivated Japanese encephalitis vaccine derived from Vero cell. Phase III, double-blind, randomized, control trial (JECEVAX, VABIOTECH, Vietnam). Viet J Prevent Med (Tạp Chí Y học Dự phòng). 2021;31(4):5–17.
Hamer DH, Chen LH. Japanese encephalitis: vaccine options and timing of pre-travel vaccination. J Trav Med. 2018;25(1).
Australian Technical Advisory Group on Immunisation (ATAGI). Australian immunisation handbook. In: Australian Government Department of Health and Aged Care, editor. Canberra: immunisationhandbook.health.gov.au. 2022.
Australian Technical Advisory Group on Immunisation (ATAGI). ATAGI clinical guidance on Japanese encephalitis virus vaccines. 2022. Available from: https://www.health.gov.au/health-alerts/japanese-encephalitis-virus-jev/atagi-clinical-guidance-on-japanese-encephalitis-virus-vaccines (accessed 15 Mar 2023).
•• Islam N, Xu C, Lau CL, Mills DJ, Clark J, Devine GJ, et al. Persistence of antibodies, boostability, and interchangeability of Japanese encephalitis vaccines: a systematic review and dose-response meta-analysis. Vaccine. 2022;40(26):3546–55. Systematic review and dose-response meta-analysis of persistence of antibodies, boostability and interchangeability of JE vaccines.
Hills SL, Walter EB, Atmar RL, Fischer M. Japanese encephalitis vaccine: recommendations of the advisory committee on immunization practices. MMWR Recomm Rep. 2019;68(2):1–33.
•• Furuya-Kanamori L, Gyawali N, Mills Mbbs Mphtm DJ, Mills C, Hugo LE, Devine GJ, et al. Immunogenicity of a single fractional intradermal dose of Japanese encephalitis live attenuated chimeric vaccine. J Travel Med. 2022. Quasi-experimental study assessing the immunogenicity and safety of intradermal dosing of a live recombinant (chimeric) JE vaccine.
Furuya-Kanamori L, Mills DJ, Lau CL. Could intradermal be an economical alternative route of administration for Japanese encephalitis vaccines? J Travel Med. 2021;28(1).
Australian Technical Advisory Group on Immunisation (ATAGI). ATAGI statement on the intradermal use of Imojev Japanese encephalitis vaccine, 22 December 2022. Available from https://www.health.gov.au/resources/publications/atagi-statement-on-the-intradermal-use-of-imojev-japanese-encephalitis-vaccine (Accessed 24 Jan 2023).
Mills DJ, Lau CL, Furuya-Kanamori L. Low uptake of Japanese encephalitis vaccination among Australian travellers. J Travel Med. 2021;28(3).
Hatz C, Werlein J, Mutsch M, Hufnagel M, Behrens RH. Japanese encephalitis: defining risk incidence for travelers to endemic countries and vaccine prescribing from the UK and Switzerland. J Travel Med. 2009;16(3):200–3.
Stanczyk NM, Behrens RH, Chen-Hussey V, Stewart SA, Logan JG. Mosquito repellents for travellers Bmj. 2015;350: h99.
Lalloo DG, Hill DR. Preventing malaria in travellers. BMJ. 2008;336(7657):1362–6.
Funding
Open Access funding enabled and organized by CAUL and its Member Institutions. SLM is supported by a National Health and Medical Research Council (NHMRC) Investigator Grant (grant number 2017229), KL by an NHMRC Senior Research Fellowship (grant number 1155005), and SM by an NHMRC Postgraduate Scholarship (1191368); PB is supported by the Royal Australasian College of Physicians Cottrell Research Establishment Fellowship.
Author information
Authors and Affiliations
Contributions
SLM wrote the first draft of the manuscript. All authors contributed to revising and editing the manuscript. All authors agreed and approved the final version manuscript.
Corresponding author
Ethics declarations
Conflict of interest
The authors declare no competing interests.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
This article is part of the Topical Collection on Tropical, Travel, and Emerging Infections
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
About this article
Cite this article
McGuinness, S.L., Muhi, S., Britton, P.N. et al. Japanese Encephalitis: Emergence in Australia. Curr Infect Dis Rep 25, 111–122 (2023). https://doi.org/10.1007/s11908-023-00804-w
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11908-023-00804-w