RESUMO
BACKGROUND AND OBJECTIVES: Japanese encephalitis (JE) is fatal endemic viral encephalitis and is common in India and other parts of the world. It has a mortality rate of around 20-30%, and most of the survivors are left with neurological deficits. Studies related to JE in India, including Jharkhand, are focused on the pediatric population. This study aims to evaluate the presentation and prognosis of JE among adults. MATERIALS AND METHODS: In this observational and prospective study, 116 patients aged 18 years or above with features of encephalitis were investigated. JE was confirmed in 32 adults by detection of immunoglobulin M (IgM) antibody in cerebrospinal fluid (CSF) through the National Institute of Virology (NIV) Pune kit. Detailed demographic profile, clinical picture, fatality rate, and prognosis were evaluated. RESULTS: Out of the 32 patients we enrolled for the study, 75% (24) were male and 75% (24) were between 18 and 40 years of age. The mean age of presentation was 29.81 ± 14.14. Most of the patients (87.5%) belonged to rural areas; also, most of them presented between August and November. In our study, the most common symptom was fever, seen in all patients, followed by altered sensorium in 24 (75%), seizure in 10 (31.25%), and headache in 8 (25%). Around 14 (43.75%) patients succumbed to death, and out of all patients who were discharged, 88.88% had neurological deficits and 11.11% of patients were healthy. The most common neurological deficit among discharged patients was an inability to speak (44.44%). CONCLUSION: We found high mortality and neurological deficits among adults. Detailed epidemiological surveys, awareness programs, and targeted use of vaccination can be helpful.
Assuntos
Encefalite Japonesa , Humanos , Masculino , Adulto , Índia/epidemiologia , Feminino , Encefalite Japonesa/epidemiologia , Encefalite Japonesa/diagnóstico , Estudos Prospectivos , Adulto Jovem , Adolescente , Pessoa de Meia-Idade , Imunoglobulina M/sangue , Imunoglobulina M/líquido cefalorraquidiano , PrognósticoRESUMO
BACKGROUND: Japanese encephalitis (JE) virus is the leading cause of vaccine-preventable encephalitis and a significant cause of disability in Asia and the western Pacific. Many countries have introduced JE vaccination programs, including several low resource countries following WHO's prioritization of JE vaccination in 2006. We sought to characterize the public health impact of JE vaccination programs. METHODOLOGY/PRINCIPAL FINDINGS: JE case data and vaccination coverage rates, were requested from country health officials in 23 JE endemic countries and Chinese Taipei. Additional data were extracted from meeting presentations and published literature. JE incidence was compared before and after vaccination using a minimum three year period pre and post program introduction or expansion. Data suitable for analysis were available for 13 JE-endemic countries and Chinese Taipei, for either all age groups or for children aged under 15 years only. Five countries and Chinese Taipei introduced vaccine prior to 2006 and the all-age JE incidence was reduced by 73-100% in about 5-20 years following introduction. Six countries have introduced JE vaccine since 2006, and JE incidence in children aged younger than 15 years has been reduced by 14-79% as of 2015-2021. JE-specific data were unavailable before introduction in Thailand and Vietnam, but vaccination programs reduced acute encephalitis incidence by 80% and 74%, respectively. Even in the programs with greatest impact, it took several years to achieve their results. CONCLUSIONS/SIGNIFICANCE: JE vaccination has greatly reduced JE in 13 JE-endemic countries and Chinese Taipei. Highest impact has been observed in countries that introduced prior to 2006, but it often took roughly two decades and substantial resources to achieve that level of success. For greatest possible impact, more recently introducing countries and funding agencies should commit to continuous improvements in delivery systems to sustain coverage after initial vaccine introduction.
Assuntos
Encefalite Japonesa , Vacinas contra Encefalite Japonesa , Humanos , Encefalite Japonesa/prevenção & controle , Encefalite Japonesa/epidemiologia , Vacinas contra Encefalite Japonesa/administração & dosagem , Vacinas contra Encefalite Japonesa/imunologia , Criança , Adolescente , Pré-Escolar , Incidência , Vacinação/estatística & dados numéricos , Lactente , Doenças Endêmicas/prevenção & controle , Programas de Imunização , Ásia/epidemiologia , Cobertura Vacinal/estatística & dados numéricos , Feminino , MasculinoRESUMO
Serological evidence has shown the presence of several mosquito-borne arbovirus infections among the inhabitants of the forest fringe areas of the tropics. Among these infections, Japanese encephalitis, dengue fever, chikungunya fever and Zika fever could be targeted for vaccination to overcome severe infection and limit the disease transmission. Seroprevalence data among this high-risk population are needed to provide an estimate of the potential cost-effectiveness of any vaccine programme targeting these infections. The present study was conducted at six indigenous people (Orang Asli) villages and FELDA (Federal Land Development Authority) settlements located at the forest fringes of Malaysia. All participants consented and provided blood samples and demographic data for the study. The blood samples were tested for the presence of antibodies against CHIKV, DENV, JEV and ZIKV individually using ELISA. Results obtained were also analysed to determine the predictors for CHIKV, DENV, JEV and ZIKV seropositivity. Among the 585 samples tested, 33.0% (N=193), 41.7% (N=244), 10.3% (N=60) and 21.0% (N=123) were positive for CHIKV IgG, DENV IgG, JEV IgG and ZIKV IgG, respectively. Approximately one-third (N=220, 37.6%) of the participants were tested negative for IgG antibodies against all four arboviruses. Age of participants and type of settlement were found to be a significant predictor for CHIKV, DENV, JEV and ZIKV seropositivity. Level of education was a significant predictor for CHIKV, DENV and ZIKV seropositivity. Gender, however, was not found to be a significant predictor for infection with any of these viruses. These findings reaffirmed the significant presence of infection involving these major arboviruses among the group of people living within the forest fringe areas of Peninsular Malaysia. Hence, any future consideration of vaccination for these infections must take into consideration the marginalized and underserved communities living at the forest fringe areas of the tropics where these infections are present.
Assuntos
Anticorpos Antivirais , Febre de Chikungunya , Dengue , Encefalite Japonesa , Infecção por Zika virus , Humanos , Malásia/epidemiologia , Estudos Soroepidemiológicos , Masculino , Feminino , Adulto , Febre de Chikungunya/epidemiologia , Encefalite Japonesa/epidemiologia , Dengue/epidemiologia , Adulto Jovem , Pessoa de Meia-Idade , Adolescente , Anticorpos Antivirais/sangue , Infecção por Zika virus/epidemiologia , Criança , Idoso , Florestas , Imunoglobulina G/sangue , Pré-EscolarRESUMO
Objective: Genotypes (G) 1, 3, and 5 of the Japanese encephalitis virus (JEV) have been isolated in China, but the dominant genotype circulating in Chinese coastal areas remains unknown. We searched for G5 JEV-infected cases and attempted to elucidate which JEV genotype was most closely related to human Japanese encephalitis (JE) in the coastal provinces of China. Methods: In this study, we collected serum specimens from patients with JE in three coastal provinces of China (Guangdong, Zhejiang, and Shandong) from 2018 to 2020 and conducted JEV cross-neutralization tests against G1, G3, and G5. Results: Acute serum specimens from clinically reported JE cases were obtained for laboratory confirmation from hospitals in Shandong (92 patients), Zhejiang (192 patients), and Guangdong (77 patients), China, from 2018 to 2020. Seventy of the 361 serum specimens were laboratory-confirmed to be infected with JEV. Two cases were confirmed to be infected with G1 JEV, 32 with G3 JEV, and two with G5 JEV. Conclusion: G3 was the primary infection genotype among JE cases with a definite infection genotype, and the infection caused by G5 JEV was confirmed serologically in China.
Assuntos
Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Genótipo , Humanos , Encefalite Japonesa/epidemiologia , Encefalite Japonesa/virologia , China/epidemiologia , Vírus da Encefalite Japonesa (Espécie)/genética , Vírus da Encefalite Japonesa (Espécie)/isolamento & purificação , Vírus da Encefalite Japonesa (Espécie)/imunologia , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Adolescente , Criança , Pré-Escolar , Idoso , Anticorpos Antivirais/sangueRESUMO
Japanese encephalitis virus (JEV) is a major threat to human health. Bangladesh is considering introducing a JEV vaccine; however, the investment case is hampered by a limited understanding of key aspects of JEV ecology. We conducted a seroprevalence study in a high-incidence region using an assay that limits cross-reactivity with dengue virus. We also trapped mosquitoes and collected information about potential host species. We used mathematical models to recover risk factors for infection and underlying probabilities of severe disease and death. We observed 19.0% [95% confidence interval (CI):17.1 to 21.1] of JEV antibodies. On average, 0.7% (95% CI: 0.2 to 2.0) of the susceptible population gets infected yearly, with pig proximity being the main human infection risk factor. Our traps captured 10 different mosquito species that have been linked with JEV transmission. We estimated that 1 in 1000 infections results in severe disease, 1 in 10,000 results in death, and 76% of severe cases are missed by surveillance.
Assuntos
Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Vacinas contra Encefalite Japonesa , Bangladesh/epidemiologia , Humanos , Encefalite Japonesa/epidemiologia , Encefalite Japonesa/prevenção & controle , Encefalite Japonesa/transmissão , Vacinas contra Encefalite Japonesa/imunologia , Vírus da Encefalite Japonesa (Espécie)/imunologia , Animais , Estudos Soroepidemiológicos , Adolescente , Adulto , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/sangue , Criança , Masculino , Feminino , Adulto Jovem , Pré-Escolar , Pessoa de Meia-Idade , Culicidae/virologia , Mosquitos Vetores/virologiaRESUMO
Pigs are the most common amplifying hosts of the Japanese encephalitis virus (JEV). In 2016, four residents on Tsushima Island who did not own pig farms were diagnosed with JE. Therefore, a serosurvey was conducted to estimate the risk and seroprevalence of JEV after the outbreak. Sera collected from 560 Tsushima Island residents between January and September 2017 were tested for neutralizing antibodies against JEV strains JaGAr01 (genotype 3) and Muar (genotype 5). Sera collected from six wild boars between June and July 2022 were tested. The seroprevalence rates of neutralizing antibodies against JaGAr01 and Muar were 38.8% and 24.6%, respectively. High anti-JEV neutralizing antibody titers of ≥320 were identified in 16 residents, including 3 younger than 6 years with prior JEV vaccination, 2 in their 40s, and 11 older than 70. However, no anti-JEV-specific IgM was detected. Residents who engaged in outdoor activities had higher anti-JEV antibody titers. Sera from wild boars were negative for JEV RNA, but four of six samples contained neutralizing antibodies against JEV. Therefore, JEV transmission continues on Tsushima Island, even in the absence of pig farms, and wild boars might serve as the amplifying hosts.
Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Sus scrofa , Doenças dos Suínos , Animais , Vírus da Encefalite Japonesa (Espécie)/imunologia , Vírus da Encefalite Japonesa (Espécie)/genética , Encefalite Japonesa/veterinária , Encefalite Japonesa/epidemiologia , Encefalite Japonesa/virologia , Encefalite Japonesa/imunologia , Suínos , Sus scrofa/virologia , Anticorpos Antivirais/sangue , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Estudos Soroepidemiológicos , Doenças dos Suínos/virologia , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/imunologia , Humanos , Masculino , Feminino , Genótipo , Japão/epidemiologiaRESUMO
BACKGROUND: The causative agents of Acute Encephalitis Syndrome remain unknown in 68-75% of the cases. In Nepal, the cases are tested only for Japanese encephalitis, which constitutes only about 15% of the cases. However, there could be several organisms, including vaccine-preventable etiologies that cause acute encephalitis, when identified could direct public health efforts for prevention, including addressing gaps in vaccine coverage. OBJECTIVES: This study employs metagenomic next-generation-sequencing in the investigation of underlying causative etiologies contributing to acute encephalitis syndrome in Nepal. METHODS: In this study, we investigated 90, Japanese-encephalitis-negative, banked cerebrospinal fluid samples that were collected as part of a national surveillance network in 2016 and 2017. Randomization was done to include three age groups (< 5-years; 5-14-years; >15-years). Only some metadata (age and gender) were available. The investigation was performed in two batches which included total nucleic-acid extraction, followed by individual library preparation (DNA and RNA) and sequencing on Illumina iSeq100. The genomic data were interpreted using Chan Zuckerberg-ID and confirmed with polymerase-chain-reaction. RESULTS: Human-alphaherpes-virus 2 and Enterovirus-B were seen in two samples. These hits were confirmed by qPCR and semi-nested PCR respectively. Most of the other samples were marred by low abundance of pathogen, possible freeze-thaw cycles, lack of process controls and associated clinical metadata. CONCLUSION: From this study, two documented causative agents were revealed through metagenomic next-generation-sequencing. Insufficiency of clinical metadata, process controls, low pathogen abundance and absence of standard procedures to collect and store samples in nucleic-acid protectants could have impeded the study and incorporated ambiguity while correlating the identified hits to infection. Therefore, there is need of standardized procedures for sample collection, inclusion of process controls and clinical metadata. Despite challenging conditions, this study highlights the usefulness of mNGS to investigate diseases with unknown etiologies and guide development of adequate clinical-management-algorithms and outbreak investigations in Nepal.
Assuntos
Encefalopatia Aguda Febril , Sequenciamento de Nucleotídeos em Larga Escala , Metagenômica , Humanos , Nepal/epidemiologia , Metagenômica/métodos , Adolescente , Pré-Escolar , Criança , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Masculino , Feminino , Encefalopatia Aguda Febril/epidemiologia , Encefalopatia Aguda Febril/virologia , Adulto Jovem , Adulto , Lactente , Encefalite Japonesa/epidemiologia , Encefalite Japonesa/virologiaRESUMO
On 12 September 2022, a 10-year-old female in Paracelis municipality, Mountain Province, the Philippines, without travel history outside the municipality, experienced acute onset of fever and a change in mental status with disorientation, an altered level of consciousness and new onset of seizures. She was hospitalized at the district hospital from 1 to 3 October 2022, before being transferred to the regional hospital. As diphtheria was originally suspected, the investigation team reviewed records and reports and interviewed key informants to gather additional information and organize case finding and contact tracing. The patient's condition was laboratory-confirmed for Japanese encephalitis virus infection. An environmental survey was carried out at the patient's residence to check for the presence of vectors and contributing factors. Exemplifying inadequate vaccination coverage for Japanese encephalitis virus in Mountain Province, the patient had not been vaccinated against the disease. It is recommended that vaccination campaigns be immediately implemented in the affected area and the surveillance system be strengthened for early detection and prompt response to the emergence of cases and outbreaks. Overall, the investigation highlighted the importance of strong surveillance and response systems for early detection and control of diseases, such as Japanese encephalitis virus. It also underscores the need for comprehensive vaccination programmes to prevent outbreaks and protect vulnerable populations.
Assuntos
Encefalite Japonesa , Humanos , Filipinas/epidemiologia , Feminino , Encefalite Japonesa/epidemiologia , Encefalite Japonesa/prevenção & controle , Criança , Vírus da Encefalite Japonesa (Espécie)/isolamento & purificaçãoRESUMO
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.
Assuntos
Encefalopatia Aguda Febril , Humanos , Índia/epidemiologia , Masculino , Adolescente , Feminino , Pré-Escolar , Criança , Adulto Jovem , Adulto , Encefalopatia Aguda Febril/epidemiologia , Encefalopatia Aguda Febril/diagnóstico , Encefalopatia Aguda Febril/etiologia , Encefalopatia Aguda Febril/virologia , Lactente , Incidência , Pessoa de Meia-Idade , Encefalite Japonesa/epidemiologia , Encefalite Japonesa/diagnóstico , Encefalite Japonesa/virologia , Vírus da Encefalite Japonesa (Espécie)/isolamento & purificação , Ensaio de Imunoadsorção Enzimática , Idoso , Tifo por Ácaros/epidemiologia , Tifo por Ácaros/diagnóstico , Tifo por Ácaros/microbiologiaRESUMO
Japanese encephalitis (JE) is a mosquito-borne disease with a spatial distribution that is linked to geo-environmental factors. The spatial distribution of JE cases and correlated geo-environmental factors were investigated in two critical counties in southern and northern China. Based on maps, enhanced thematic mapper (ETM) remote sensing datasets from Landsat and spatial datasets of JE cases, spatial distribution and spatial cluster analyses of JE cases at the village scale were performed by using the standard deviational ellipse and Ripleys K-function. Global and regional spatial cluster analyses of JE cases were also performed by using Moran's index. Regression analysis was used to analyze the relationships between geo-environmental characteristics and the risk of JE cases. At the study sites, the JE cases were not spatially clustered at the village or district (global) level, whereas there was a spatial cluster at the district (local) level. Diversity-related features for JE patients at the district and village levels were detected at two sites. In the southern counties, the distance of a village from a road was related to the village-level JE risk (OR: 0.530, 95 CI: 0.297-0.947, P = 0.032), and the number of township-level JE cases was linked to the distance of the district center from the road (R =-0.467, P = 0.025) and road length (R = 0.516, P = 0.012) in the administrative area. In northern China, the modified normalized difference water index (MNDWI) in the 5 km buffer around the village was related to village-level JE risk (OR: 0.702, 95% CI: 0.524-0.940, P = 0.018), and the number of township-level JE cases was related to the MNDWI in the administrative region (R =-0.522, P = 0.038). This study elucidates the spatial distribution patterns of JE cases and risk, as well as correlated geo-environmental features, at various spatial scales. This study will significantly assist the JE control efforts of the local Centers for Disease Control and Prevention (CDC), which is the base-level CDC, particularly concerning the allocation of medicine and medical staff, the development of immunological plans, and the allocation of pesticides and other control measures for the mosquito vectors of JE.
Assuntos
Encefalite Japonesa , Análise Espacial , China/epidemiologia , Humanos , Encefalite Japonesa/epidemiologia , Análise por Conglomerados , Feminino , Masculino , Criança , Adulto , Adolescente , Pessoa de Meia-Idade , Adulto Jovem , Pré-Escolar , Lactente , Idoso , Meio Ambiente , Topografia MédicaRESUMO
Japanese encephalitis (JE), caused by the Japanese encephalitis virus (JEV) infection, continues to pose significant public health challenges worldwide despite efficient vaccines. The virus is classified into five genotypes, among which genotype V (GV) was not detected for a long period after its initial isolation in 1952, until reports emerged from China and the Republic of Korea (ROK) since 2009. The characteristics of the virus are crucial in estimating its potential epidemiological impact. However, characterization of GV JEVs has so far been limited to two strains: Muar, the original isolate, and XZ0934, isolated in China. Two additional ROK GV JEV isolates, NCCP 43279 and NCCP 43413, are currently available, but their characteristics have not been explored. Our phylogenetic analysis revealed that GV virus sequences from the ROK segregate into two clades. NCCP 43279 and NCCP 43413 belong to different clades and exhibit distinct in vitro phenotypes. NCCP 43279 forms larger plaques but demonstrates inefficient propagation in cell culture compared to NCCP 43413. In vivo, NCCP 43279 induces higher morbidity and mortality in mice than NCCP 43413. Notably, NCCP 43279 shows more severe blood-brain barrier damage, suggesting superior brain invasion capabilities. Consistent with its higher virulence, NCCP 43279 displays more pronounced histopathological and immunopathological outcomes. In conclusion, our study confirms that the two ROK isolates are not only classified into different clades but also exhibit distinct in vitro and in vivo characteristics.
Assuntos
Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Genótipo , Filogenia , Vírus da Encefalite Japonesa (Espécie)/genética , Vírus da Encefalite Japonesa (Espécie)/isolamento & purificação , Vírus da Encefalite Japonesa (Espécie)/classificação , Animais , República da Coreia/epidemiologia , Encefalite Japonesa/virologia , Encefalite Japonesa/veterinária , Encefalite Japonesa/epidemiologia , Camundongos , Humanos , Virulência , Linhagem Celular , FemininoRESUMO
OBJECTIVES: To investigate the distribution and prevalence of Japanese encephalitis virus (JEV) antibody (as evidence of past infection) in northern Victoria following the 2022 Japanese encephalitis outbreak, seeking to identify groups of people at particular risk of infection; to investigate the distribution and prevalence of antibodies to two related flaviviruses, Murray Valley encephalitis virus (MVEV) and West Nile virus Kunjin subtype (KUNV). STUDY DESIGN: Cross-sectional serosurvey (part of a national JEV serosurveillance program). SETTING: Three northern Victorian local public health units (Ovens Murray, Goulburn Valley, Loddon Mallee), 8 August - 1 December 2022. PARTICIPANTS: People opportunistically recruited at pathology collection centres and by targeted recruitment through community outreach and advertisements. People vaccinated against or who had been diagnosed with Japanese encephalitis were ineligible for participation, as were those born in countries where JEV is endemic. MAIN OUTCOME MEASURES: Seroprevalence of JEV IgG antibody, overall and by selected factors of interest (occupations, water body exposure, recreational activities and locations, exposure to animals, protective measures). RESULTS: 813 participants were recruited (median age, 59 years [interquartile range, 42-69 years]; 496 female [61%]); 27 were JEV IgG-seropositive (3.3%; 95% confidence interval [CI], 2.2-4.8%) (median age, 73 years [interquartile range, 63-78 years]; 13 female [48%]); none were IgM-seropositive. JEV IgG-seropositive participants were identified at all recruitment locations, including those without identified cases of Japanese encephalitis. The only risk factors associated with JEV IgG-seropositivity were age (per year: prevalence odds ratio [POR], 1.07; 95% CI, 1.03-1.10) and exposure to feral pigs (POR, 21; 95% CI, 1.7-190). The seroprevalence of antibody to MVEV was 3.0% (95% CI, 1.9-4.5%; 23 of 760 participants), and of KUNV antibody 3.3% (95% CI, 2.1-4.8%; 25 of 761). CONCLUSIONS: People living in northern Victoria are vulnerable to future JEV infection, but few risk factors are consistently associated with infection. Additional prevention strategies, including expanding vaccine eligibility, may be required to protect people in this region from Japanese encephalitis.
Assuntos
Anticorpos Antivirais , Surtos de Doenças , Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Humanos , Estudos Transversais , Vírus da Encefalite Japonesa (Espécie)/imunologia , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , Encefalite Japonesa/epidemiologia , Encefalite Japonesa/imunologia , Adulto , Feminino , Masculino , Anticorpos Antivirais/sangue , Idoso , Vitória/epidemiologia , Imunoglobulina G/sangue , Adulto Jovem , Vírus da Encefalite do Vale de Murray/imunologia , Adolescente , Fatores de RiscoRESUMO
Japanese encephalitis virus (JEV) is a major cause of encephalitis in Southeast Asia. Tamil Nadu, a state located in the southern part of India, contributes substantially to the national burden of human JE cases every year. However, limited information is available on the epidemiology of JE in pig populations of Tamil Nadu. A cross-sectional study was conducted to assess JEV prevalence in pig populations of Tamil Nadu. A total of 710 pigs reared in 118 farms across 10 districts of Tamil Nadu were sampled using multistage cluster random sampling. Serum samples were analyzed for their JEV status using Immunoglobulin M (IgM) and Immunoglobulin G (IgG) Enzyme-Linked Immunosorbent Assay (ELISA). At the animal-level, the apparent JEV seroprevalence was 60.4% (95% CI: 56.8% - 64.0%) and the true seroprevalence was 50.1% (95% CI: 47.0% - 53.2%). The herd-level apparent seroprevalence was 94.1% (95% CI: 88.1% - 97.5%) and the true seroprevalence was 93.3% (95% CI: 89.5% - 96.2%). The intensity of JEV circulation was high in all the districts, with seroprevalence ranging between 43% and 100%. Pigs across all age categories were seropositive and a high overall seroprevalence of 95.2% (95% CI: 76.2% - 99.9%) was recorded in pigs older than 12 months. JEV seropositivity was recorded in all the seasons but the prevalence peaked in the monsoon (67.9%, 95% CI: 61.1% - 74.2%) followed by winter (65.1%, 95%CI: 57.4% - 72.2%) and summer (53.3%, 95% CI: 47.8% - 58.8%) seasons. The results indicate that JEV is endemic in pigs populations of the state and a one health approach is essential with collaborative actions from animal and public health authorities to control JE in Tamil Nadu, India.
Assuntos
Anticorpos Antivirais , Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Doenças dos Suínos , Animais , Índia/epidemiologia , Estudos Soroepidemiológicos , Vírus da Encefalite Japonesa (Espécie)/imunologia , Encefalite Japonesa/epidemiologia , Encefalite Japonesa/veterinária , Encefalite Japonesa/virologia , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/virologia , Estudos Transversais , Anticorpos Antivirais/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Prevalência , Feminino , Ensaio de Imunoadsorção Enzimática , Masculino , Estações do AnoRESUMO
BACKGROUND: Japanese encephalitis (JE) is a serious health concern in China, with approximately 80 % of global infections occurring in China. To develop effective prevention and control strategies, this study explored the epidemiological characteristics of JE in China based on spatiotemporal data, to understand the patterns and trends of JE incidence in different regions and time periods. METHOD: The incidence and mortality rates of JE were extracted from the Public Health Data Center, the official website of the National Health Commission of the People's Republic of China, and the National Notifiable Infectious Disease Surveillance System from 2004 to 2019. Joinpoint regression was applied to examine the spatiotemporal patterns and annual percentage change in incidence and mortality of the JE. RESULTS: From 2004 to 2019, a total of 43,569 cases of JE were diagnosed, including 2081 deaths. The annual incidence rate of JE decreased from 0.4171/100,000 in 2004 to 0.0298/100,000 in 2019, with an annual percentage change (APC) of -13.5 % (P < 0.001). The annual mortality rate of JE showed three stages of change, with inflection points in 2006 and 2014. The incidence and mortality rates of JE have declined in all provinces of China, and more cases were reported in 0-14 years of age, accounting for nearly 80 % of all patients. CONCLUSIONS: The morbidity and mortality rates of JE in China are generally on a downward trend, and emphasis should be placed on strengthening disease surveillance in special areas and populations, popularizing vaccination, and increasing publicity.
Assuntos
Encefalite Japonesa , Vigilância da População , Análise Espaço-Temporal , Humanos , Encefalite Japonesa/epidemiologia , Encefalite Japonesa/mortalidade , China/epidemiologia , Incidência , Criança , Pré-Escolar , Adolescente , Lactente , Adulto , Feminino , Masculino , Adulto Jovem , Pessoa de Meia-Idade , Recém-NascidoRESUMO
OBJECTIVES: To determine the proportion of people in New South Wales towns at high risk of Japanese encephalitis virus (JEV) infections during the 2022 outbreak; to identify risk factors for JEV infection. STUDY DESIGN: Cross-sectional serosurvey study of the seroprevalence of JEV-specific antibodies in NSW. SETTING, PARTICIPANTS: Convenience sample of people (all ages) from five regional NSW towns deemed to be at high risk of JEV infections after first outbreak of Japanese encephalitis in southeastern Australia in early 2022 (Balranald, Corowa, Dubbo, Griffith, Temora), 21 June - 22 July 2022. MAIN OUTCOME MEASURES: Proportion of people seropositive for JEV total antibody, assayed by defined epitope-blocking enzyme-linked immunosorbent assay; prevalence odds ratios for exposure risk factors and protective behaviours. RESULTS: Eighty of 917 eligible participants (559 girls or women, 61%; 42 Aboriginal and Torres Strait Islander people, 4.6%; median age, 52 years [IQR, 37-62 years]) were seropositive for JEV-specific total antibody (8.7%); the median age of seropositive people was 61 years (IQR, 48-70 years). The seropositivity proportion was largest for people aged 65 years or more (30 of 192; weighted proportion, 13.7%) and larger for male than female participants (30 of 358, 10.6% v 50 of 559, 7.5%). Five of 42 samples from Aboriginal and Torres Strait Islander participants were seropositive (12%). We found mixed associations with a range of potential risk factors. CONCLUSION: We found evidence for a substantial number of JEV infections in five regional NSW towns during a single arbovirus season in 2022. Public health responses, including effective surveillance, vaccination against JEV, and mosquito management, are critical for controlling outbreaks. Promoting behaviours that reduce exposure to mosquitoes is a core component of prevention, particularly when the vaccine supply is limited.
Assuntos
Anticorpos Antivirais , Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Anticorpos Antivirais/sangue , Estudos Transversais , Surtos de Doenças , Vírus da Encefalite Japonesa (Espécie)/imunologia , Encefalite Japonesa/epidemiologia , Encefalite Japonesa/imunologia , New South Wales/epidemiologia , Fatores de Risco , Estudos SoroepidemiológicosRESUMO
Introduction: Widespread transmission of Japanese encephalitis virus (JEV) genotype four (GIV) occurred across mainland Australia in 2022. This resulted in forty-five human cases, including seven deaths, and the identification of JEV infection in over 80 commercial piggeries. Materials and Methods: We collected mosquitoes which were trapped using CO2-baited light traps deployed near piggeries reporting disease or in regions linked to human cases in the Wide Bay region in the state of Queensland. Mosquitoes from four traps yielded JEV RNA by real-time RT-PCR. Pools containing RNA positive mosquitoes were inoculated onto mosquito cell monolayers. Discussion: A single isolate of JEV was obtained from a pool of mixed mosquito species. Near whole genome sequencing and phylogenetic analysis of the JEV isolate demonstrated its high genomic relatedness with JEV GIV pig sequences sampled from Queensland and the state of New South Wales in 2022. Conclusion: We report the first isolation of JEV GIV from mosquitoes collected in Australia. With only a few JEV GIV isolates available globally, the isolate we report will be essential for future research of JEV host interactions, evolution and disease markers, and development of effective therapies, vaccines, diagnostic assays, and mosquito control strategies.
Assuntos
Culicidae , Vírus da Encefalite Japonesa (Espécie) , Genótipo , Filogenia , Animais , Vírus da Encefalite Japonesa (Espécie)/genética , Vírus da Encefalite Japonesa (Espécie)/isolamento & purificação , Vírus da Encefalite Japonesa (Espécie)/classificação , Culicidae/virologia , Austrália/epidemiologia , Mosquitos Vetores/virologia , Suínos , Queensland/epidemiologia , Encefalite Japonesa/virologia , Encefalite Japonesa/veterinária , Encefalite Japonesa/epidemiologia , RNA Viral/genética , HumanosRESUMO
AIMS: Japanese encephalitis (JE) is endemic in India. Although pigs are considered important hosts and sentinels for JE outbreaks in people, limited information is available on JE virus (JEV) surveillance in pigs. METHODS AND RESULTS: We investigated the spatio-temporal distribution of JEV seroprevalence and its association with climate variables in 4451 samples from pigs in 10 districts of eastern Uttar Pradesh, India, over 10 years from 2013 to 2022. The mean seroprevalence of IgG (2013-2022) and IgM (2017-2022) was 14% (95% CI 12.8-15.2) and 10.98% (95% CI 9.8-12.2), respectively. Throughout the region, higher seroprevalence from 2013 to 2017 was observed and was highly variable with no predictable spatio-temporal pattern between districts. Seroprevalence of up to 60.8% in Sant Kabir Nagar in 2016 and 69.5% in Gorakhpur district in 2017 for IgG and IgM was observed, respectively. IgG seroprevalence did not increase with age. Monthly time-series decomposition of IgG and IgM seroprevalence demonstrated annual cyclicity (3-4 peaks) with seasonality (higher, broader peaks in the summer and monsoon periods). However, most variance was due to the overall trend and the random components of the time series. Autoregressive time-series modelling of pigs sampled from Gorakhpur was insufficiently predictive for forecasting; however, an inverse association between humidity (but not rainfall or temperature) was observed. CONCLUSIONS: Detection patterns confirm seasonal epidemic periods within year-round endemicity in pigs in eastern Uttar Pradesh. Lack of increasing age-associated seroprevalence indicates that JEV might not be immunizing in pigs which needs further investigation because models that inform public health interventions for JEV could be inaccurate if assuming long-term immunity in pigs. Although pigs are considered sentinels for human outbreaks, sufficient timeliness using sero-surveillance in pigs to inform public health interventions to prevent JEV in people will require more nuanced modelling than seroprevalence and broad climate variables alone.
Assuntos
Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Doenças dos Suínos , Animais , Encefalite Japonesa/epidemiologia , Encefalite Japonesa/veterinária , Encefalite Japonesa/virologia , Suínos , Índia/epidemiologia , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/virologia , Vírus da Encefalite Japonesa (Espécie)/imunologia , Estudos Soroepidemiológicos , Imunoglobulina M/sangue , Estações do Ano , Anticorpos Antivirais/sangue , Imunoglobulina G/sangue , Análise Espaço-TemporalRESUMO
Abstract: Japanese encephalitis, caused by the JE virus transmitted by mosquitoes, is the most common type of epidemic encephalitis in Asia. It is endemic in most of South and Southeast Asia, but the number of cases can vary greatly between areas. While many infections do not lead to disease, the symptomatic cases can be very severe and life-threatening. It mainly affects children, whereas adults are generally immune to the disease due to either being infected in childhood or receiving vaccination. However, individuals who are not immune, such as travelers from non-endemic countries, are susceptible to the disease when exposed to the virus for the first time, regardless of age. Without antiviral treatment options, vaccination is the only strategy to establish effective protection against Japanese encephalitis.