Japanese Encephalitis Transmission Research Articles

A Mathematical modelling for co-infection dynamics of Japanese encephalitis-Dengue and influence of JE Vaccine on Dengue disease

A non-linear deterministic mathematical model has been described with the co-infection dynamics of Japanese encephalitis(JE) and dengue disease, incorporating the JE vaccine. A basic reproduction number is discussed to study transmission potential of the co-infection model. In co-infection model, disease-free equilibrium points of Japanese encephalitis and dengue, along with endemic, are presented in system and investigated their stability with the help of their specified method. Our analysis suggests that vaccination against Japanese encephalitis positively affect control of co-infection. By using Center Manifold Theory, the model undergoes backwards bifurcation phenomenon and this has been occurred when basic reproduction number is smaller than unity. It is shown that by taking simultaneous preventive steps, the basic reproduction number of co-infection can be reduced to less than one after eliminating both infections. Sensitivity analysis has been performed to determine which parameters significantly affect disease dynamics. The effects of these parameters on transmission of disease were investigated using a numerical simulation. According to the findings, we obtain that JE-dengue co-infection can be managed with use of JE vaccine, also minimize JE transmission rate rapidly.

Distribution of Voltage Gated Sodium Channel (VGSC) Gene Mutational Variation And Acetylcholinesterase-1 (ACE-1) as A Marker For Insecticide Resistance In Culex spp. Mosquitoes In Surabaya

Culex spp. is a vector for Japanese Encephalitis (JE) and filariasis in Indonesia. JE is caused by Japanese Encephalitis Virus (JEV). JEV attacks the central nervous system and causes inflammation of the brain, lifelong disability, and even death. Filariasis is a chronic infectious disease that can cause permanent disability. Transmission of JE and filariasis can increase due to the density of Culex spp mosquitoes. The purpose of this study was to identify the distribution of mutation variations in the Voltage Gated Sodium Channel (VGSC) and acetylcholinesterase-1 (ace-1) genes in Culex spp. mosquitoes in Surabaya. Mutation variations of the VGSC Culex spp. gene show that there are three genotypes, namely wildtype (LL), heterozygous (LS, FS), and homozygous (FF, SS). Heterozygous (FS) and homozygous (FF, FS) genotypes caused by point mutations in codon 1014 of the VGSC gene are found in the Culex spp. mosquito population in Surabaya. Heterozygous (LF) genotype was not detected in the Culex spp. mosquito population in Surabaya. Another study in Nigeria showed that homozygous/FF genotypes (45.1%) were more prevalent than heterozygotes/LF (36.3%) and wildtypes/LL (18.6%).

An Overview of Japanese Encephalitis in Australia: Trends, Impact and Interventions

Japanese Encephalitis (JE) is caused by infection with the Japanese encephalitis virus (JEV). This vector-borne disease has been listed as a nationally notifiable public health risk in various countries. Predominantly found in Southeast Asia, JE can result in long-term neurological and psychiatric sequelae in both adults and children and is the leading cause of viral encephalitis in this region. Globally, there are an estimated 100,000 cases of JE and 25,000 associated deaths per year. Despite the significant effort to stop JE transmission through implementing vaccination programmes, JEV infection continues to be a global problem, with recent outbreaks in several countries, including outside of Asia. This raises a public health alert and establishes a need for future surveillance. Here, we reviewed the recent JE epidemic in Australia, focusing on its trends, impact and intervention. We recommend that a collaborative research effort together with a globally unified disease control strategy is urgently required to improve our understanding of JEV transmission and surveillance and to be better prepared for future outbreaks.

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 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.

Relative Abundance, Distribution, and Diversity of Mosquitoes in District Peshawar, Charsadda, and Swabi

Aims: To date, there are 3601 named mosquito species recognized worldwide representing the diverse and medically important fly family Culicidae. In this study, after collection and identification of mosquitoes from the study area, their diversity, relative abundance (RA), and distribution (C) were evaluated for the prevention of mosquito-borne diseases.
 Place and Duration of Study: Mosquitoes in their immature and adult stages were collected from their habitats in district Peshawar, Charsadda, and Swabi from September 2021 till April 2022.
 Study Design: The immature samples were collected from various places such as pots, small water containers, bushy places under trees, and from the edges of some open drains. While the adult mosquitoes were collected during the same period by using the light trap and Pyrethrum spray methods for outdoor and indoor environment, respectively.
 Methodology: 252 and 295 mosquitoes in their larval and pupal, and adult stages, respectively, were collected and brought to the laboratory for rearing and were observed on daily basis. All the adult specimens were preserved using silica gel in test tubes. The specimens were kept in entomological boxes after rearing and preservation for identification. Taxonomic identification of the adult mosquitoes was made using the key provided in the fauna of British India.
 Results: The identification showed the presence of four species belonging to three genera: Culex quinquefasciatus; Aedes aegypti, Aedes albopictus; and Armigeres subalbatus. Culex quinquefasciatus was the most abundant specie found at all the study sites (C=100% and RA=44.24%), while Armigeres subalbatus was found to be an infrequent specie (C=25% and RA=20.66%). Several indices were also calculated to find out the diversity of the mosquitoes. The Shannon-Weiner index (H) for the month of April and December are 1.32 and 0.60, respectively, representing highest and lowest diversities among the study period.
 Conclusion: The study found that Culex quinquefasciatus, Aedes aegypti, and Aedes albopictus are the most prevalent species in the study area and their presence increases the risk of mosquito-borne diseases such as West Nile virus, Filariasis, and Japanese Encephalitis transmission in the area. The study suggests further research to examine the diversity of mosquitoes more thoroughly to design effective vector control strategies and predict the risk of future disease outbreaks.

A review of vectors, vector borne diseases, vector control and their impact on public health

Mosquitoes are most important insect vectors for human disease transmission. Dengue, yellow fever, chikungunya, and zika are all spread by Aedes mosquitoes in many parts of the world. The primary vector of human malaria transmission is Anopheles. Culex is responsible for the transmission of Japanese encephalitis, lymphatic filariasis and West Nile virus fever. Synthetic pesticides have been successfully utilized in mosquito-control programmes for several decades. However, there are a number of disadvantages to the chemical method. As a result, there has been a rise in concern in the usage of biological agents for mosquito control in recent years. Because of their highly effective mosquitocidal activity, Bacillus sphaericus and Bacillus thuringiensis israelensis have been utilized extensively. While insecticide-based interventions have successfully reduced mosquito populations for a number of years, the reliance on a few number of insecticides has now led to the evolution of resistance. So there is a need to search for novel mosquitocidal bacteria for control the mosquito species. Since soil is one of the world's most diversified environments in which bacteria and fungi are abundant, screening of soil samples for isolation of novel mosquitocidal bacteria is attempted.

Analysis of entomological indices for transmission of Japanese encephalitis in Malkangiri district, Odisha State, east central India during 2015–2019

ABSTRACT There have been repeated episodes of the outbreak of Japanese encephalitis (JE) in Malkangiri district of Odisha State in the recent past. In the current study, we aimed to assess the entomological parameters of JE vectors in the district. Prevalence of JE vector species, their per man hour density (PMHD), dusk index (DI), human blood index (HBI), infection status and other factors responsible for transmission of JE were assessed over 5 years (2015–2019). Culex vishnui was the predominant JE vector species (32.0%) collected, followed by Cx. whitmorei (27.1%) and Cx. tritaeniorhynchus (18.0%). The PMHD was higher in cattle shed (CS) than human dwelling (HD) and outdoor resting collection (ODRC) sites for all the JE vector species, except An. barbirostris. In particular, the PMHD of Cx. vishnui (8.02), Cx. whitmorei (5.71) and Cx. tritaeniorhynchus (5.01) were significantly higher in CS than HD and ODRC. The DI of Cx. vishnui (2.47), Cx. whitmorei (1.66) and Cx. tritaeniorhynchus (1.59) was significantly higher in CS compared to HD and ODRC. The HBI of Cx. vishnui was 0.015, whereas the HBI of Cx. tritaeniorhynchus was 0.009 in the study area. Among the 829 pools of JE vector species subjected to PCR, JE virus was isolated from one pool of Cx. vishnui. Based on the abundance of JE vectors and JE virus isolation from Cx. vishnui, it is requisite to implement systematic and long-term control measures for effective control of JE vector species in Malkangiri district, Odisha State.

A mathematical study of dynamical model for Japanese encephalitis-dengue co-infection using JE vaccine

A nonlinear deterministic mathematical model has been described with the co-infection dynamics of Japanese encephalitis (JE) and dengue disease, incorporating the JE vaccine. Basic mathematical results have been discussed along with their stabilities. By using center manifold theory, the model undergoes a backwards bifurcation phenomenon and this has occurred when the basic reproduction number is smaller than unity. Sensitivity analysis has been performed to determine which parameters significantly affect disease dynamics. The effects of these parameters on the transmission of disease were investigated using a numerical simulation. According to the findings, we ascertain that JE-dengue co-infection can be managed with the use of JE vaccine, also minimising JE transmission rate rapidly.

Japanese Encephalitis Transmission Trends in Gansu, China: A Time Series Predictive Model Based on Spatial Dispersion

Japanese Encephalitis Transmission Trends in Gansu, China: A Time Series Predictive Model Based on Spatial Dispersion

The impact of time delay in the transmission of Japanese encephalitis without vaccination

In this manuscript, the influence of time delay in the transmission of Japanese encephalitis without vaccination model has been studied. The time delay is because of the existence of an incubation period during which the Japanese encephalitis virus reproduces enough in the mosquitoes with the goal that it tends to be transmitted by the mosquitoes to people. The motivation behind this manuscript is to assess the influence of the time delay it takes to infect susceptible human populations after interacting with infected mosquitoes. The steadystate and the threshold value R0 of the delay model were resolved. This value assists with setting up the circumstance that ensures the asymptotic stability of relating equilibrium points. Utilizing the delay as a bifurcation parameter, we built up the circumstance for the presence of a Hopf bifurcation. Moreover, we infer an express equation to decide the stability and direction of Hopf bifurcation at endemic equilibrium by using center manifold theory and normal structure strategy. It has been seen that delay plays a vital role in stability exchanging. Furthermore, the presence of Hopf bifurcation is affected by larger values of virus transmission rate from an infected mosquito to susceptible individuals and the natural mortality of humans in a model. Finally, to understand some analytical outcomes, the delay framework is simulated numerically.

Bio-ecological study of Culex quinquefasciatus as a potential vector of Japanese encephalitis in some provinces in Indonesia

Culex quinquefasciatus is a mosquito known as Japanese encephalitis (JE) vector in several regions in Indonesia. The bioecological study is essential to optimize the vector control of JE. The purpose of the study was to obtain the ecological information of Cx. quinquefasciatus in 15 provinces in Indonesia: Aceh, West Sumatra, Lampung, Bangka Belitung, Banten, West and East Java, West and South Kalimantan, North and Southeast Sulawesi, East and West Nusa Tenggara, Maluku, and North Maluku. Mosquitoes were collected using the human landing catches (HLCs), light trap, and morning resting collection. The larva survey was conducted in potential habitats of Cx. quinquefasciatus. The mosquito was detected for the JE virus using the polymerase chain reaction (PCR) method. The distribution of Cx. quinquefasciatus was recorded using a GPS tool and visualized using Global Mapper. The results showed that Cx. quinquefasciatus in 15 provinces had similar behavior. The Cx. quinquefasciatus sucked blood indoors and was found throughout the night. Peak density of Cx. quinquefasciatus varies by province. Cx. quinquefasciatus breeding places are found in most ecosystems in various altitudes. Based on PCR examination, the JE virus has not been detected, thus lowering the potential for JE transmission in some provinces in Indonesia.

Environmental factors and spatiotemporal distribution of Japanese encephalitis after vaccination campaign in Guizhou Province, China (2004\u20132016)

BackgroundAlthough a vaccination campaign has been conducted since 2004, Japanese encephalitis (JE) is still a public health problem in Guizhou, one of the provinces with the highest incidence of JE in China. The aim of this study was to understand the spatiotemporal distribution of JE and its relationship with environmental factors in Guizhou Province in the post-vaccination era, 2004–2016.MethodsWe collected data on human JE cases in Guizhou Province from 2004 to 2016 from the national infectious disease reporting system. A Poisson regression model was used to analyze the relationship between JE occurrence and environmental factors amongst counties.ResultsOur results showed that the incidence and mortality of JE decreased after the initiation of vaccination. JE cases were mainly concentrated in preschool and school-age children and the number of cases in children over age 15 years was significantly decreased compared with the previous 10 years; the seasonality of JE before and after the use of vaccines was unchanged. JE incidence was positively associated with cultivated land and negatively associated with gross domestic product (GDP) per capita, vegetation coverage, and developed land. In areas with cultivated land coverage < 25%, vegetation coverage > 55%, and urban area coverage > 25%, the JE risk was lower. The highest JE incidence was among mid-level GDP areas and in moderately urbanized areas.ConclusionsThis study assessed the relationship between incidence of JE and environmental factors in Guizhou Province. Our results highlight that the highest risk of JE transmission in the post-vaccination era is in mid-level developed areas.

Urban Japanese Encephalitis: Time for a Reality Check

Expansion of JEV from its historical rural origin in the Oriental Realm has been evident. Apprehensions were raised by several investigators that the occurrence of Japanese Encephalitis (JE) in the urban areas is a possibility. Creating wetlands, rice farms, and piggeries close to the rural-urban periphery to support the increasing urban population facilitates the migration of mosquitoes, ardeid birds, and pigs in these areas. The presence of vectors (Culex vishnui complex), reservoirs (the ardeid birds), and the amplifying hosts (pigs) together in these urban and peri-urban areas creates highly conducive situations for the JE transmission thus, creating an urban ecotype for JE. Apart from the primary vectors, JEV has been isolated from several species of mosquitoes belonging to different genera. JE antibodies have also been detected in several birds and mammals other than the known reservoirs and amplifying hosts. Such mosquitoes, birds, and mammals might be acting as complementary or maintenance vectors and reservoirs, respectively, which likely can keep the virus circulating perennially in nature. The reported occurrence of JE in urban areas from different geographical locations is decidedly indicative of the reality of the urban JE. It is thus pertinent that an inclusive approach encompassing sustained epidemiological surveillance and monitoring be adopted to formulate season-wise and area-wise strategies to contain JE both in rural and urban areas.

The detection of Japanese encephalitis virus in Megachiropteran bats in West Kalimantan, Indonesia: A potential enzootic transmission pattern in the absence of pig holdings

The West Kalimantan province in Borneo island, Indonesia belongs to endemic area of Japanese encephalitis (JE) that accounts for approximately 30% of total cases yearly. As the presence of pig holdings is uncommon in West Kalimantan, another reservoir host might have played a role in the local transmission of JE virus in this area. Current study aimed to identify the potential role of bats in the local transmission of JE by performing molecular detection of JE virus in bats and mosquitoes using RT-PCR. Sample collection was performed in 3 districts in West Kalimantan, covering 3 different ecosystems: forest, coastal, and residential areas. Bat collection was performed using mist net and harp net, while mosquito collection was carried out using animal-baited trap and human landing collection. A total of 373 blood samples from bats were tested for JE virus, among which 21 samples (5.6%) showed positive results, mainly from Cynopterus brachyotis (lesser short-nosed fruit bat) found in residential areas. Out of 53 mosquito pools, 3 JE-positive pools of Culex tritaeniorhynchus and Cx. vishnui were collected at the same location as JE-positive bats. Current study showed the first evidence of JE virus detection in several species of Megachiropteran bats in Indonesia, demonstrated the potential role of frugivorous bats in local transmission of JE in West Kalimantan. More aggressive measures are required in JE risk mitigation, particularly in initiating JE vaccination campaign and in avoiding disruption of bats’ natural habitats through changes in land-use.

Seasonal dynamics and relative abundance of seven Japanese encephalitis vectors of Culex sitiens group and their association with meteorological factors in various ecological habitats of Chandigarh and its surrounding areas

Japanese encephalitis (JE) is one of the most common cause of acute viral encephalitis which poses serious infection of the brain. Species under Culex sitiens group are major vectors responsible for the transmission of JE. The knowledge about the occurrence of Culex sitiens group in Chandigarh and its adjoining areas is very scanty. Hence, present investigations have been carried out to study seasonal dynamics and relative abundance of JE vectors in these areas. Detailed surveys have been carried out in various ecological habitats of Chandigarh from June 2017–November 2019. The monthly meteorological parameters of the study–area like temperature, rainfall, and relative humidity were compared and statistically correlated with JE vector density. As many as 34 mosquito species belonging to 8 genera have been recorded. Genus Culex contributed maximum (69.40%) of the total catch which included 7 incriminated JE species from the studied habitats. These vectors showed highest density in monsoon and post–monsoon periods. The abundance of Culex sitiens vectors indicates their importance for evaluation of the seasonal dynamics which ultimately demarcates the risk of JE outbreak. The observation over a period of three years is highly significant to assess the seasonal dynamicity of JE vector population in different seasons and its abundance in different ecological habitats.

Seasonal abundance and infection of Japanese encephalitis vectors from Gorakhpur district, Uttar Pradesh, India.

Japanese encephalitis (JE) is a major public health problem in many states of India. Uttar Pradesh state contributes 75% of the total cases reported. A longitudinal study was undertaken to find out the seasonal abundance, infection in the JE vectors in Gorakhpur region of Uttar Pradesh, and intervention strategies like indoor residual spraying and long-lasting insecticidal nets were adopted. The vector abundance was monitored from July 2013 to August 2016 at fortnightly intervals and identified using standard mosquito identification keys and screened for viral infection. Intervention measures like indoor residual spraying with lambda-cyhalothrin 10% WP at 25 mg/m2 in 58 gramasabha in Bhathat Block and long-lasting insecticidal nets were distributed @ 2 LLIN for each household with 5-6 members in 5 villages of Korabar block. A total of 5,36,609 mosquitoes constituting 34 species and 10 genera were collected during this study period. Among the JE vector, peak abundance of Culex tritaeniorhynchus was recorded just before the JE season from July to October in all the blocks. There was a marked reduction in the density of Cx. tritaeniorhynchus from July compared to baseline year 2014 in Bhathat Block where indoor residual spraying (IRS) was performed in June 2015. The vector density declined in 5 villages of Khorabar Block where long-lasting impregnated bed nets (LLINs) were distributed during July 2016. The present study provided knowledge about the seasonal JE vector density and JE virus infection in mosquitoes during the monsoon season in Gorakhpur region of Uttar Pradesh. IRS and the personal protection measure like LLINs were distributed to interrupt the JE transmission in this area which gave encouraging results.

An Observational Study of JE Cases Detected in National Centre for Disease Control from January 2017 to December 2019

Introduction: Japanese Encephalitis (JE), a leading cause of AES is a vector-borne disease is caused by the JE virus belonging to the genus Flavivirus (Flaviviridae family), and transmitted by bite of Culex vishnui subgroup tritaeniorhynchus, the most important reported vector species for JE transmission in India. Methodology: A study was conducted on 1131 AES suspected cases in JE laboratory of Centre for Arboviral and Zoonotic diseases, National Centre for Disease Control (NCDC), Delhi from tertiary care referral hospitals of Delhi for laboratory confirmation of JE during the period from January 2017- December 2019. CSF and/ or Serum Samples from 1131 hospitalized AES suspected cases mostly from Delhi, UP, Haryana addresses. They were tested and interpreted for IgM antibodies by the JE IgM Capture ELISA kit (National Institute of Virology, Pune). The demographic profile (age/ sex/ seasonality/ place) of JE confirmed cases were analyzed. Result: 77 (6.8%) out of 1131 AES suspected cases were JE confirmed. 48 patients (62.2%) were of pediatric age group 19 (24.7%) were of middle age adult and 10 (13.0 %) were older age adults out of 77 JE confirmed cases.. The JE cases occurred throughout the year, though maximum cases were observed in the monsoon seasons (June-October) in our study. In our study most of the JE confirmed patients were residents of state of Delhi, Uttar Pradesh and Haryana. Conclusion: The study attempts to highlight the need of strengthening quality of laboratory detection of JE in AES cases, need for intensive vector control policy and re-evaluation of the policy of JE vaccination in India.

Nonlinear and Threshold Effect of Meteorological Factors on Japanese Encephalitis Transmission in Southwestern China.

Although previous studies have reported that meteorological factors might affect the risk of Japanese encephalitis (JE), the relationship between meteorological factors and JE remains unclear. This study aimed to evaluate the relationship between meteorological factors and JE and identify the threshold temperature. Daily meteorological data and JE surveillance data in Dazhou, Sichuan, were collected for the study period from 2005 to 2012 (restricting to May-October because of the seasonal distribution of JE). A distributed lag nonlinear model was used to analyze the lagged and cumulative effect of daily average temperature and daily rainfall on JE transmission. A total of 622 JE cases were reported over the study period. We found JE was positively associated with daily average temperature and daily rainfall with a 25-day lag and 30-day lag, respectively. The threshold value of the daily average temperature is 20°C. Each 5°C increase over the threshold would lead to a 13% (95% CI: 1-17.3%) increase in JE. Using 0 mm as the reference, a daily rainfall of 100 mm would lead to a 132% (95% CI: 73-311%) increase in the risk of JE. Japanese encephalitis is climate-sensitive; meteorological factors should be taken into account for the future prevention and control measure making, especially in a warm and rainy weather condition.

Long-Term Epidemiological Dynamics of Japanese Encephalitis Infection in Gansu Province, China: A Spatial and Temporal Analysis.

.The incidence of Japanese encephalitis (JE) has greatly declined in China. However, JE incidence has significantly increased in Gansu in recent years, on the top of ranks among all provinces in China. To explore the spatial spread and resurgence of JE transmission in Gansu in the past 60 years, we collected yearly data on reported JE in each county (1958–2017) and monthly data on JE cases (1968–2017), respectively. We grouped the dataset into six categories, each consisting of a 10-year period between 1958 and 2017. Spatial cluster analysis was applied to identify the potential space–time clusters of JE incidence, and logistic regression models were used to identify the spatial and temporal dispersion of JE. Japanese encephalitis incidence in Gansu showed an upward trend from 1970 to 1977 and peaked in 1974, then declined, and fluctuated over the study period until an outbreak again in 2017. Japanese encephalitis incidence for the first 30-year period (1958–1987) peaked in September each year and thereafter peaked in July and August during 1988–2017. Spatial cluster analysis showed the geographical range of JE transmission fluctuated over the past 60 years. The high-incidence clusters of JE were primarily concentrated in the southeast of Gansu. We found significant space–time clustering characteristics of JE in Gansu, and the geographical range of notified JE cases has significantly expanded over recent years. The potential rebound of JE transmission occurred in 2016–2017 should be placed on the top priority of government work during the control and prevention of JE in Gansu, China.