Incidence Of Japanese Encephalitis Research Articles

Aetiological profile of acute encephalitis syndrome in Assam, India, during a 4-year period from 2019 to 2022.

Acute encephalitis syndrome (AES) is a major public health concern in India as the aetiology remains unknown in the majority of cases with the current testing algorithm. We aimed to study the incidence of Japanese encephalitis (JE) and determine the aetiology of non-JE AES cases to develop an evidence-based testing algorithm. Cerebrospinal fluid (CSF) samples were tested for Japanese encephalitis virus by ELISA and polymerase chain reaction (PCR). Multiplex real-time PCR was done for Dengue, Chikungunya, West Nile, Zika, Enterovirus, Epstein Barr Virus, Herpes Simplex Virus, Adenovirus, Cytomegalovirus, Herpesvirus 6, Parechovirus, Parvovirus B19, Varicella Zoster Virus, Scrub typhus, Rickettsia species, Leptospira, Salmonella species, Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Plasmodium species and by ELISA for Mumps and Measles virus. Of the 3173 CSF samples, 461 (14.5%) were positive for JE. Of the 334 non-JE AES cases, 66.2% viz. Scrub typhus (25.7%), Mumps (19.5%), Measles (4.2%), Parvovirus B19 (3.9%) Plasmodium (2.7%), HSV 1 and 2 (2.4%), EBV and Streptococcus pneumoniae (2.1% each), Salmonella and HHV 6 (1.2% each) were predominant. Hence, an improved surveillance system and our suggested expanded testing algorithm can improve the diagnosis of potentially treatable infectious agents of AES in India.

The spatiotemporal distribution and prognostic factors of Japanese encephalitis in Shanxi Province, China, 2005-2022.

Japanese encephalitis (JE) is a naturally occurring localized disease caused by the Japanese encephalitis virus, which is spread by the Culex tritaeniorhynchus. China has a high rate of JE. Shanxi, located in North China, has a high prevalence of adult JE. Adult JE has more severe complications, mortality, and a higher disease burden, making it a public health issue. This retrospective study examined the dynamic epidemic changes, high-risk areas of JE, and clinical characteristics and prognostic factors of adult JE in Shanxi Province. The findings revealed that July to September was the primary epidemic season of JE and that JE cases were mainly in individuals over the age of 40. The incidence of JE from 2005 to 2022 demonstrated a positive spatial correlation with significant clustering characteristics, with high-incidence clusters in the south and southeast. Multivariate logistic regression analysis revealed that higher cerebrospinal fluid pressure, higher white blood cell counts, higher neutrophil percentage, deep coma, and lower albumin were independent factors for poor prognosis of adult JE. The developed risk prediction model holds great promise in early prognosis assessment of patients, providing a basis for clinical decision-making and early clinical intervention.

Japanese Encephalitis Vaccine Acceptance and Strategies for Travelers: Insights from a Scoping Review and Practitioners in Endemic Countries.

Japanese encephalitis (JE) remains the cause of vaccine-preventable encephalitis in individuals living in endemic areas and international travelers. Although rare, the disease's high fatality rate emphasizes the need for effective immunization. This review aims to provide updated data on the JE burden between 2017 and 2023, vaccine acceptance, and vaccine strategies for travelers. We prospectively identified studies, using MEDLINE and PubMed, published through 2023. JE incidence has decreased in local populations and remains low among travelers from non-endemic countries. The local JE risk cannot be utilized to determine traveler risk. Adult travelers naïve to JEV infection or immunization may be at potentially higher risk. The JE vaccine acceptance rates among international travelers visiting JE endemic areas range from 0.2% to 28.5%. The cost of the vaccine and low risk perception could be barriers to JE vaccination. For travelers, an accelerated two-dose regimen of inactivated Vero cell JE vaccine (JE-VC) or a single dosage of live attenuated JE vaccine (JE-LV) may be an option. In conclusion, the JE burden among residents and travelers is lower, but the risk is not negligible. Practitioners should prioritize sharing knowledge, increasing awareness, and promoting vaccinations and preventive measures to reduce tourists' risk of JE along their journey.

Cost-effectiveness analysis of Japanese Encephalitis (JE) vaccination program in Bali Province, Indonesia

ObjectiveThe incidence of Japanese Encephalitis (JE) in Bali Province remains high, and is one among the highest in Indonesia. The Indonesian Government initiated the JE vaccination campaign followed by a JE vaccine introduction program in Bali Province in 2018. The JE vaccination program then has been fully integrated into the provincial routine immunization program since 2019. We conducted a retrospective economic analysis of JE vaccination program in Bali Province, Indonesia; considering multiple vaccination strategies. MethodsWe conducted a cost-effectiveness analysis using a decision analytic model comparing two vaccination strategies with no vaccination from the societal and government perspectives. These vaccination strategies were: (1) JE vaccination campaign and introduction program, and (2) a routine JE vaccination program. We compared costs and outcomes for three hypothetical cohorts of 100,000 children followed from birth to the age of 10 years, with impacts measured throughout the child’s life-time. We measured the economic consequences as costs per case, per death, and per disability-adjusted life year (DALY) averted. ResultsA routine JE immunization program was the most cost-effective strategy with a cost per DALYs averted of US$ 212.59 and US$ 94.09 from the government and societal perspectives respectively. In contrast, costs per DALYs averted through the JE vaccination campaign and introduction strategy was US$ 1,473.53 and US$ 1,224.20 from the government and societal perspectives respectively. ConclusionsBoth JE vaccination strategies are cost-effective but they are not cost-saving when compared to no immunization program.

A decision support tool for risk-benefit analysis of Japanese encephalitis vaccine in travellers.

During pre-travel consultations, clinicians and travellers face the challenge of weighing the risks verus benefits of Japanese encephalitis (JE) vaccination due to the high cost of the vaccine, low incidence in travellers (~1 in 1million), but potentially severe consequences (~30% case-fatality rate). Personalised JE risk assessment based on the travellers' demographics and travel itinerary is challenging using standard risk matrices. We developed an interactive digital tool to estimate risks of JE infection and severe health outcomes under different scenarios to facilitate shared decision-making between clinicians and travellers. A Bayesian network (conditional probability) model risk-benefit analysis of JE vaccine in travellers was developed. The model considers travellers' characteristics (age, sex, co-morbidities), itinerary (destination, departure date, duration, setting of planned activities) and vaccination status to estimate the risks of JE infection, the development of symptomatic disease (meningitis, encephalitis), clinical outcomes (hospital admission, chronic neurological complications, death) and adverse events following immunization. In low-risk travellers (e.g. to urban areas for <1month), the risk of developing JE and dying is low (<1per million) irrespective of the destination; thus, the potential impact of JE vaccination in reducing the risk of clinical outcomes is limited. In high-risk travellers (e.g. to rural areas in high JE incidence destinations for >2months), the risk of developing symptomatic disease and mortality is estimated at 9.5and 1.4per million, respectively. JE vaccination in this group would significantly reduce the risk of symptomatic disease and mortality (by ~80%) to 1.9and 0.3per million, respectively. The JE tool may assist decision-making by travellers and clinicians and could increase JE vaccine uptake. The tool will be updated as additional evidence becomes available. Future work needs to evaluate the usability of the tool. The interactive, scenario-based, personalised JE vaccine risk-benefit tool is freely available on www.VaxiCal.com.

The spatial-temporal pattern of Japanese encephalitis and its influencing factors in Guangxi, China.

Japanese encephalitis (JE) is a major global public health threat. Using Japanese encephalitis incidence data from 2004 to 2010 in Guangxi Province, China, this study comprehensively explored the driving forces and the interactive effects between environmental and social factors of Japanese encephalitis using the Geo-detector method. The results indicated that the incidence of Japanese encephalitis showed a fluctuating downward trend from 2004 to 2010. The onset of JE was seasonal, mainly concentrated in June-July, and highly aggregated in northwestern Guangxi. Among the factors associated with Japanese encephalitis, days with temperatures >30 °C, accumulated temperatures >25 °C, slope, the normalized difference vegetation index, the gross domestic product of tertiary industries, the gross domestic product of primary industries and the number of pigs slaughtered showed higher contributions to Japanese encephalitis incidence. An enhanced interactive effect was found between environmental and social factors, and the interaction between days with humidity levels >80% and the gross domestic product of tertiary industries had the greatest combined effect on JE. These findings enhanced the understanding of the combined effect of social and environmental factors on the incidence of Japanese encephalitis and could help improve Japanese encephalitis transmission control and prevention strategies.

Japanese Encephalitis in Assam: A Sentinel Case

Since times immemorial, mosquito borne diseases have proved to be a great menace to the human population. Their severe clinical manifestations and high mortality contribute to their deadly status. Japanese encephalitis (JE), is one such mosquito borne viral disease mainly prevalent in Southeast Asia including India, particularly in the state of Assam. It mainly affects the central nervous system, resulting in various neurological and locomotor disorders and change in mental status. Seizures are also observed, although they are more common in children. JE is caused by a virus of the Flaviviridae family, transmitted by a Culicine mosquito, Culex tritaeniorynchus. Pigs are considered to be the amplifier hosts. Throughout the years, JE has become endemic in many districts of Assam affecting many lives in the outbreaks that occur each year, more particularly in the rural and agricultural areas. Assam’s climactic conditions, agricultural habits and patterns, and the lifestyle of its population play a major role in the epidemiology of the disease. With the establishment of JE surveillance and vaccination programmes by the government, the JE incidence rate has decreased. However, outbreaks of JE still continue to occur, often with serious complications and a high mortality. This concise review article gives a short summarization of Japanese encephalitis along with its history, epidemiology, vector and host biology, pathology, clinical observations and immunoprophylaxis with respect to the state of Assam, India.

Incidence of Japanese Encephalitis and Acute Encephalitis Syndrome Hospitalizations in the Medium-Endemic Region in Central India

BackgroundWe estimated the incidence of Japanese encephalitis (JE) and acute encephalitis syndrome (AES) following routine immunization with the live-attenuated SA 14-14-2 JE vaccine.MethodsWe implemented enhanced surveillance of AES and JE hospitalizations in endemic districts in Maharashtra and Telangana States during 2015–2016 and 2018–2020. We estimated incidence and compared differences in the incidence of JE and AES between two states, and vaccinated and unvaccinated districts during two study periods. We also considered secondary data from public health services to understand long-term trends from 2007 to 2020.ResultsThe annual AES incidence rate of 2.25 cases per 100,000 children in Maharashtra during 2018–2020 was significantly lower than 3.36 cases per 100,000 children during 2015–2016. The six JE-vaccinated districts in Maharashtra had significantly lower incidence rates during 2018–2020 (2.03, 95% CI 1.73–2.37) than in 2015–16 (3.26, 2.86–3.70). In addition, the incidence of both JE and AES in two unvaccinated districts was higher than in the vaccinated districts in Maharashtra. Telangana had a lower incidence of both JE and AES than Maharashtra. The AES incidence rate of 0.95 (0.77–1.17) during 2018–2020 in Telangana was significantly lower than 1.67 (1.41–1.97) during 2015–2016.ConclusionsThe annual incidence rate of Japanese encephalitis was < 1 case per 100,000 children. It indicated accelerated control of Japanese encephalitis after routine immunization. However, the annual incidence of acute encephalitis syndrome was still > 1 case per 100,000 children. It highlights the need for improving surveillance and evaluating the impacts of vaccination.

Adults in Northwest China experienced the largest outbreak of Japanese encephalitis in history 10 years after the Japanese encephalitis vaccine was included in the national immunization program: A retrospective epidemiological study.

Mainland China included Japanese encephalitis (JE) vaccine in the national immunization program in 2008 to control the JE epidemic. However, Gansu province in Western China experienced the largest JE outbreak since 1958 in 2018. We conducted a retrospective epidemiological study to explore the causes of this outbreak. We found that adults aged ≥20 years (especially those in rural areas) were the main JE cases in Gansu Province, with a significant increase in the JE incidence in older adults aged ≥60 years in 2017 and 2018. In addition, JE outbreaks in Gansu Province were mainly located in the southeastern region, while the temperature and precipitation in Gansu Province were gradually increasing in recent years, which made the JE epidemic areas in Gansu Province gradually spread to the western of Gansu Province. We also found that adults aged ≥20 years in Gansu Province had lower JE antibody positivity than children and infants, and the antibody positivity rate decreased with age. In the summer of 2017 and 2018, the density of mosquitoes (mainly the Culex tritaeniorhynchus) in Gansu Province was significantly higher than in other years, and the genotype of JEV was mainly Genotype-G1. Therefore, in the future JE control in Gansu Province, we need to strengthen JE vaccination for adults. Moreover, strengthening mosquito surveillance can provide early warning of JE outbreaks and the spread of epidemic areas in Gansu Province. At the same time, strengthening JE antibody surveillance is also necessary for JE control.

Japanese encephalitis transmission trends in Gansu, China: A time series predictive model based on spatial dispersion

ObjectiveThis study serves to ascertain trends of space and time for Japanese encephalitis (JE) transmission at the township-level and develop an innovative time series predictive model to predict the geographical spread of JE in Gansu Province, China. MethodsWe collected weekly data on JE from 2005 to 2019 at the township-level. Kriging interpolation maps were used to visualize the trend of the epidemic spread of JE, and linear regression models were used to calculate the monthly changes in minimum longitude and maximum latitude of emerging towns with JE to assess the speed of the epidemic's spread to the northwest. Additionally, we utilized a time series Seasonal Autoregressive Integrated Moving Average (SARIMA) model to dynamically predict the ongoing weekly number of JE emerging townships. ResultsThe Kriging difference map revealed a significant trend of JE spread towards the northwest. Our regression model indicated that the rate of decrease in minimum longitude was approximately 0.64 km per month, while the rate of increase in maximum latitude was approximately 1.00 km per month. Furthermore, the SARIMA pattern (2,0,0)(2,0,1)52 exhibited a better goodness-of-fit for predicting JE transmission, with an overall agreement of 93.27% to 94.23%. ConclusionOur study highlights the expansion of JE cases towards the northwest of Gansu, indicating the need for ongoing surveillance and control efforts. The use of the SARIMA model provides a valuable tool for predicting the trend of JE spatial dispersion, thereby improving early warning systems. Our findings suggest that the number of emerging townships can be used to predict the trend of JE spatial dispersion, providing crucial insights for future research on JE incidence.

Increasing seroprevalence of Japanese encephalitis virus in even-toed hoofed mammals (Artiodactyla species) associated with an upsurge of human cases in South Korea

The annual incidence of Japanese encephalitis (JE) has increased markedly in South Korea since 2010. We hypothesized that this increase was associated with higher frequencies of JE virus in animals. We analyzed 5201 serum samples collected from even-toed hoofed mammals (Artiodactyla species) across South Korea from 2008 to 2012 using a stratified two-stage probability approach. The highest annual incidence of human JE cases and deaths occurred in 2010. Cases increased from six (no deaths) in 2008-2009 to 26 cases (seven deaths) in 2010. The JE virus seroprevalence in deer and elk fawns increased from 2.4% in 2008 to 24.1% in 2009, and in wild boars, it increased from 19.3% to 55.0% in the same period, which preceded the surge of human cases. Furthermore, the seroprevalence in calves increased from 15.3% in 2008 to 35.8% in 2010, and that in lambs and goat kids, increased from 8.5% in 2009 to 26.2% in 2010, which coincided with the surge in humans. Our findings show that the increased incidence of human JE in South Korea was temporally associated with an increasing seroprevalence in the Artiodactyla species. Surveillance of sentinel animals may be useful to predict the emergence of JE in humans.

Evaluation of dogs (Canis familiaris) as an indicator of Japanese encephalitis (JE) outbreaks: A retrospective serological study in the Seoul metropolitan area around the 2010 resurgence of JE in the Republic of Korea

Japanese encephalitis (JE) is a mosquito-borne zoonotic neurological disease caused by Japanese encephalitis virus (JEV). JEV is the most common cause of viral encephalitis in Southeast Asia and the Western Pacific Rim. The fatality rate due to JE can reach 25% and up to 50% of the patients who survive develop permanent neurological damage. The annual incidence of human JE markedly increased in the Republic of Korea (ROK) in 2010 but the reason for the reemergence of JE in the ROK has not been established. This study aimed to assess the extent of exposure of domestic dogs to JEV in the Seoul metropolitan area, one of the most populated areas in the world. This cross-sectional study serologically investigated the spread of JEV in the dog population. Using serum neutralization test, we examined 3597 serum samples collected from pet, shelter, stray, and farmed dogs in the Seoul metropolitan area from 2006 to 2012. JEV-neutralizing antibodies found in shelter, stray, and farmed dogs sampled in approximately 2010 demonstrated increased JEV circulation in the dog population during the 2010 resurgence of JE reported among humans in the ROK. Five out of 1102 pet dogs (0.5%) were found to be neutralizing antibodies against JEV and 24 of 719 shelter dogs (3.1%) were positive with a peak of 13.0% in 2010. In addition, 25 of 690 stray dogs (3.6%) were positive with a peak of 9.7% in 2009, a year before the 2010 resurgence of JE. Furthermore, 39 of 1086 farmed dogs (3.6%) were seropositive with a peak of 9.2% in 2009. We therefore suggest that monitoring dog populations for seroconversion or seropositive dogs within JEV-active endemic areas may be useful for identifying risk areas for JE outbreaks and that JEV activity in dogs can be an indicator as the harbingers of JEV in humans.

Coverage of Japanese encephalitis routine vaccination among children in Central India.

We aimed to estimate the coverage of Japanese encephalitis (JE) vaccination in central India to help explain the continued occurrence of JE disease despite routine vaccination. We implemented a 30-cluster survey for estimating the coverage of JE vaccination in the medium-endemic areas implemented with JE vaccination in central India. The parents were enquired about the uptake of the JE vaccine by their children aged 2 to 6 years, followed by verification of the immunization cards at home along with reasons for non-vaccination. Vaccination coverage was reported as a percentage with 95% confidence intervals. We estimated high coverage of live-attenuated SA 14-14-2 JE vaccination in Maharashtra (94.8%, 95% CI 92.7-96.3) and Telangana (92.8%, 90.0-94.9). The vaccination card retention was 90.3% in Maharashtra and 70.4% in Telangana state. There were no gender differences in coverage in both states. A similar level of JE vaccination coverage was observed during the year 2013 to 2021 in both states. In Maharashtra, the maximum age-wise coverage was 96.6% in the >60 months age category, whereas in Telangana it was in the <24 months age category (97.2%). The timeliness of JE vaccination was appropriate and similar in both states. We found very good agreement between JE and Measles-Rubella vaccinations administered simultaneously. The reasons for non-vaccination were the shortage of vaccines and the parental migration for work. The coverage of Japanese encephalitis vaccination was high in medium-endemic regions in central India. Vaccination effectiveness studies may help further explain the continued incidence of Japanese encephalitis. This article is protected by copyright. All rights reserved.

Interventions for the Prevention and Treatment of Japanese Encephalitis.

Purpose of ReviewJapanese encephalitis (JE), a clinical indication of JE virus–induced brain inflammation, is the most prevalent cause of viral encephalitis in the world. This review gives a comprehensive update on the epidemiology, clinical features, therapeutic trials and approaches for preventing the spread of JE. It also outlines the different JE vaccines used in various countries and recommendations for administration of JE vaccines.Recent FindingsAccording to the WHO, annual incidence of JE is estimated to be approximately 68,000 cases worldwide. It is widespread across Asia–Pacific, with a potential for worldwide transmission. In endemic locations, JE is believed to affect children below 6 years of age, but in newly affected areas, both adults and children are at risk due to a lack of protective antibodies. Various vaccines have been developed for the prevention of JE and are being administered in endemic countries.SummaryJE is a neuroinvasive disease that causes symptoms ranging from simple fever to severe encephalitis and death. Despite a vast number of clinical trials on various drugs, there is still no complete cure available, and it can only be prevented by adequate vaccination. Various nanotechnological approaches for the prevention and treatment of JE are outlined in this review. Supplementary InformationThe online version contains supplementary material available at 10.1007/s11908-022-00786-1.

Effect of different vaccine strategies for the control of Japanese encephalitis in mainland China from 1961 to 2020: A quantitative analysis

BackgroundWe aimed to quantify the impact of each vaccine strategy (including the P3-inactivated vaccine strategy [1968–1987], the SA 14-14-2 live-attenuated vaccine strategy [1988–2007], and the Expanded Program on Immunization [EPI, 2008–2020]) on the incidence of Japanese encephalitis (JE) in regions with different economic development levels. MethodsThe JE incidence in mainland China from 1961 to 2020 was summarized by year, then modeled and analyzed using an interrupted time series analysis. ResultsAfter the P3-inactivated vaccine was used, the JE incidence in Eastern China, Central China, Western China and Northeast China in 1968 decreased by 39.80 % (IRR = 0.602, P < 0.001), 7.80 % (IRR = 0.922, P < 0.001), 10.80 % (IRR = 0.892, P < 0.001) and 31.90 % (IRR = 0.681, P < 0.001); the slope/trend of the JE incidence from 1968 to 1987 decreased by 30.80 % (IRR = 0.692, P < 0.001), 29.30 % (IRR = 0.707, P < 0.001), 33.00 % (IRR = 0.670, P < 0.001) and 41.20 % (IRR = 0.588, P < 0.001). After the SA 14-14-2 live-attenuated vaccine was used, the JE incidence in Eastern China and Northeast China in 1988 decreased by 2.60 % (IRR = 0.974, P = 0.009) and 14.70 % (IRR = 0.853, P < 0.001); the slope/trend of the JE incidence in Eastern China and Central China from 1988 to 2007 decreased by 4.60 % (IRR = 0.954, P < 0.001) and 4.70 % (IRR = 0.953, P < 0.001). After the EPI was implemented, the JE incidence in Eastern China, Central China and Western China in 2008 decreased by 10.50 % (IRR = 0.895, P = 0.013), 18.00 % (IRR = 0.820, P < 0.001) and 24.20 % (IRR = 0.758, P < 0.001), the slope/trend of the JE incidence in Eastern China from 2008 to 2020 decreased by 17.80 % (IRR = 0.822, P < 0.001). ConclusionsEach vaccine strategy has different effects on the JE incidence in regions with different economic development. Additionally, some economically underdeveloped regions have gradually become the main areas of the JE outbreak. Therefore, mainland China should provide economic assistance to areas with low economic development and improve JE vaccination plans in the future to control the epidemic of JE.

Emerging Genotype IV Japanese Encephalitis Virus Outbreak in New South Wales, Australia.

The detection of a new and unexpected Japanese encephalitis virus (JEV) outbreak in March 2022 in Australia, where JEV is not endemic, demanded the rapid development of a robust diagnostic framework to facilitate the testing of suspected patients across the state of New South Wales (NSW). This nascent but comprehensive JEV diagnostic service encompassed serological, molecular and metagenomics testing within a centralised reference laboratory. Over the first three months of the outbreak (4 March 2022 to 31 May 2022), 1,061 prospective samples were received from 878 NSW residents for JEV testing. Twelve confirmed cases of Japanese encephalitis (JE) were identified, including ten cases diagnosed by serology alone, one case by metagenomic next generation sequencing and real-time polymerase chain reaction (RT-PCR) of brain tissue and serology, and one case by RT-PCR of cerebrospinal fluid, providing an incidence of JE over this period of 0.15/100,000 persons in NSW. As encephalitis manifests in <1% of cases of JEV infection, the population-wide prevalence of JEV infection is likely to be substantially higher. Close collaboration with referring laboratories and clinicians was pivotal to establishing successful JEV case ascertainment for this new outbreak. Sustained and coordinated animal, human and environmental surveillance within a OneHealth framework is critical to monitor the evolution of the current outbreak, understand its origins and optimise preparedness for future JEV and arbovirus outbreaks.

The epidemiology and disease burden of children hospitalized for viral infections within the family Flaviviridae in China: A national cross-sectional study.

BackgroundViruses of the family Flaviviridae, including Japanese encephalitis virus (JEV), dengue virus (DENV), yellow fever virus (YFV) and hepatitis C virus (HCV), are widely distributed worldwide. JEV, DENV and YFV belong to the genus Flavivirus, whereas HCV belongs to the genus Hepacivirus. Children’s symptoms are usually severe. As a result, rates of hospitalization due to infection with these viruses are high. The epidemiology and disease burden of hospitalized children have rarely been described in detail to date. The objective of this study was to report the general epidemiological characteristics, clinical phenotype, length of stay (LOS), burden of disease, and potential risk factors for hospitalized children infected with JEV, DENV, YFV, or HCV in Chinese pediatric hospitals.MethodologyA cross-sectional study of epidemiology and disease burden of children hospitalized for Flaviviridae virus infections between December 2015 and December 2020 in China was performed. Face sheets of discharge medical records (FSMRs) were collected from 27 tertiary children’s hospitals in the Futang Research Center of Pediatric Development and aggregated into FUTang Update medical REcords (FUTURE). Information on sociodemographic variables, clinical phenotype, and LOS as well as economic burden was included in FSMRs and compared using appropriate statistical tests.FindingsThe study described 490 children aged 0–15 years hospitalized for infections with Flaviviridae viruses. Japanese encephalitis (JE) cases are the highest, accounting for 92.65% of the total hospitalization cases caused by Flaviviridae virus infection. The incidence of JE peaked from July to October with a profile of a high proportion of severe cases (68.06%) and low mortality (0.44%). Rural children had a significantly higher incidence than urban children (91.63%). Most hospitalized dengue cases were reported in 2019 when dengue outbreaks occurred in many provinces of China, although only 14 dengue cases were collected during the study period. Yellow fever (YF) is still an imported disease in China. The hospitalizations for children with hepatitis C (HC) were not high, and mild chronic HC was the main clinical phenotype of patients. Among the four viral infections, JE had the highest disease burden (LOS and expenditure) for hospitalized children.ConclusionFirst, the present study reveals that JE remains the most serious disease due to Flaviviridae virus infection and threatens children’s health in China. Many pediatric patients have severe illnesses, but their mortality rate is lower, suggesting that existing treatment is effective. Both JEV vaccination and infection control of rural children should represent a focus of study. Second, although the dual risks of indigenous epidemics and imports of DENV still exist, the prevalence of DENV in children is generally manageable. Third, YFV currently shows no evidence of an epidemic in China. Finally, the proportion of children with chronic hepatitis C (CHC) is relatively large among hospitalized children diagnosed with HCV. Thus, early and effective intervention should be offered to children infected with HCV to ease the burden of CHC on public health.

Impact of the expanded program on immunization on the incidence of Japanese encephalitis in different regions of Mainland China: An interrupt time series analysis

In 2008, Mainland China included the Japanese encephalitis (JE) vaccine in the Expanded Program on Immunization (EPI) to control the JE epidemic. However, Northwest China experienced the largest JE outbreak since 1994 in 2018, and the effects of the EPI in different regions are unclear. Therefore, we used an interrupted time series design to evaluate the effects of the EPI in different regions. In this study, β1 and β1+β3 represented the slope or trend of the JE incidence before and after the EPI, respectively; β2 was the level change of the JE incidence immediately after the EPI; β3 represented the slope change of the JE incidence before and after the EPI. We found that the JE incidence in all regions showed a decreasing trend before the EPI (β1<0.000, P<0.05). The JE incidence in Mainland China (β2=−7.669, P<0.05), East China (β2=−9.791, P<0.05), Central China (β2=−10.695, P<0.05), South China (β2=−6.551, P<0.05) and Southwest China (β2=−2.216, P<0.05) decreased by 7.669/100,000, 9.791/100,000, 10.695/100,000, 6.551/100,000 and 2.216/100,000 immediately after the EPI, and the EPI had short-term effects on the JE incidence in these regions. The slope of the JE incidence in Mainland China (β3=0.272, P<0.05), East China (β3=0.337, P<0.05), Central China (β3=0.381, P<0.05), South China (β3=0.254, P<0.05) and Southwest China (β3=0.081, P<0.05) increased by 0.272, 0.337, 0.381, 0.254 and 0.081 after the EPI, and the EPI had long-term effects on the JE incidence in these regions. The JE incidence in many regions (excluding North China) showed a decreasing trend after the EPI (β1+β3 <0.000). Northwest China (GDP from 2008 to 2020 ranked last in Mainland China) and Southwest China (GDP from 2008 to 2020 ranked fifth in Mainland China), with underdeveloped economy, used to be low-epidemic regions of JE, but they have become high-epidemic regions in recent years. Economic development may contribute to the geographic variations in the effects of the EPI. Therefore, it is significant for JE control in Mainland China to increase support for underdeveloped regions and adjust the vaccine strategy according to the new epidemic situation of JE.

Spatial statistical and environmental correlation analyses on vector density, vector infection index and Japanese encephalitis cases at the village and pigsty levels in Liyi County, Shanxi Province, China

BackgroundIn the eco-epidemiological context of Japanese encephalitis (JE), geo-environmental features influence the spatial spread of the vector (Culex tritaeniorhynchus, Giles 1901) density, vector infection, and JE cases.MethodsIn Liyi County, Shanxi Province, China, the spatial autocorrelation of mosquito vector density, vector infection indices, and JE cases were investigated at the pigsty and village scales. The map and Enhanced Thematic Mapper (ETM) remote sensing databases on township JE cases and geo-environmental features were combined in a Geographic Information System (GIS), and the connections among these variables were analyzed with regression and spatial analyses.ResultsAt the pigsty level, the vector density but not the infection index of the vector was spatially autocorrelated. For the pigsty vector density, the cotton field area was positively related, whereas the road length and the distance between pigsties and gullies were negatively related. In addition, the vector infection index was correlated with the pigsty vector density (PVD) and the number of pigs. At the village level, the vector density, vector infection index, and number of JE cases were not spatially autocorrelated. In the study area, the geo-environmental features, vector density, vector infection index, and JE case number comprised the Geo-Environment-Vector-JE (GEVJ) intercorrelation net system. In this system, pig abundance and cotton area were positive factors influencing the vector density first. Second, the infection index was primarily influenced by the vector density. Lastly, the JE case number was determined by the vector infection index and the wheat area.ConclusionsThis study provided quantitative associations among geo-environmental features, vectors, and the incidence of JE in study sties, one typical northern Chinese JE epidemiological area without rice cultivation. The results highlighted the importance of using a diverse range of environmental management methods to control mosquito disease vectors and provided useful information for improving the control of vector mosquitoes and reducing the incidence of JE in the northern Chinese agricultural context.Graphical

Japanese encephalitis virus in India: An update on virus genotypes.

Japanese encephalitis (JE) is a leading cause of viral encephalitis in Southeast Asia. It is a serious public health issue in India, and cases have been emerging in newer areas of the country. Although vaccination efforts have already been initiated in the country since 2006 and later through the Universal Immunization Programme in 2011, still a significant reduction in the number of cases has to be achieved since an escalating trend of JE incidence has been reported in certain States such as Assam, Uttar Pradesh and West Bengal. Moreover, fresh cases of JE have been reported from certain pockets in Odisha as well. Despite the mass JE vaccination programme implemented in prioritized endemic zones in the country in 2011, a shift in the age group of JE virus (JEV) infection was noticed affecting the adult population in West Bengal. The recent detection of the circulation of genotype I (GI) in Gorakhpur, Uttar Pradesh and the co-circulation of GI and genotype III (GIII) in West Bengal are probably a warning signal for the public health personnel to strengthen the surveillance system in all endemic hotspots in the country. The abrupt emergence of JEV genotype V (GV) in China and Korea in 2009, after its first detection in Malaya in 1952, endemic countries have been cautioned to strengthen their surveillance, because GV has been suspected of getting dispersed efficiently in other parts of Asia. Moreover, the reduced protection efficiency of the JEV GIII-based vaccine against the JEV genotype V further warrants careful evaluation of the ongoing vaccination strategies in the endemic countries, anticipating the possible incursion of GV and its impact on future control strategies. In view of the above facts, the present communication reviews the current knowledge on the molecular epidemiology of JEV in India vis-a-vis the global scenario and discusses the future priorities in JEV research in India for effectively designing control strategies.