The relationship between MMP-2 rs243865, MMP-9 rs398242 and CXCL-12 rs1801157 gene polymorphisms with Japanese encephalitis disease and disease outcome in North Indian population

Background & objectives: Japanese encephalitis virus (JEV) is one of the most important causes of acute and uncontrolled inflammatory disease in Asia. Matrix metalloproteinases (MMPs) and chemokines play a detrimental role in the host response to JE disease, aetiology, and disease outcome. Evidently, MMPs are widely circulated in the brain and regulate various process including microglial activation, inflammation, blood-brain barrier disruption as well as affects central nervous system (CNS). The present study was to assess the association of single nucleotide polymorphisms of MMP-2, MMP-9 and chemokine (CXCL-12/SDF1-3’) in the north Indian population. Methods: We performed case-control study comprising of 125 patients and 125 healthy controls in north Indian population. Genomic DNA was extracted from whole blood and gene polymorphism have been determined by PCR-RFLP method. Results: MMP-2, MMP-9 and CXCL-12 gene was not significantly associated with JE disease, but homozygous (T/T) genotype of MMP-2 was statically associated with disease outcome (p=0.05, OR=0.110). A/G and G/G genotype of CXCL-12 was significantly associated with severity of disease. (p=0.032, OR=5.500, p=0.037, OR= 9.167). The serum level of MMP-2 was observed significantly increased in JE patients with homozygous (T/T) genotype whereas increased MMP-9 level was associated with heterozygous genotype. Interpretation & conclusion: MMP-2, MMP-9 and CXCL-12 gene polymorphism were not associated with JE susceptibility, but MMP-2 may be contributed to disease protection. CXCL-12 was associated with disease severity. In our concern this is the first report from northern India.

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.

Molecular epidemiology of Japanese encephalitis in pigs and risk factors associated with causing Japanese encephalitis in pigs of Lakhimpur, the first case reported in the district of North East India

Background & objectives: Japanese encephalitis (JE) is a major public health problem in India. The first outbreaks of JE have been reported from the North-eastern regions of Assam, particularly from the Lakhimpur district of Assam between July–August 1989. In Assam every year many people died due to JE. This study was performed to investigate the molecular epidemiology of JE in pigs in Lakhimpur district of Assam and the risk factors associated with causing Japanese encephalitis in pigs. This study will help to map out the endemic regions and to know where and when to apply the most control strategies towards the prevention and control of the disease. Methods: A total of 342 serum samples from pigs were collected from 10 organized and 20 unorganized farms from 9 blocks and recorded to age, sex and breed and tested by RT-PCR. Pig farms and the surrounding environment were studied for assessment of farm-level risk factors responsible for JEV infection in pigs. Results: Out of 342 samples tested for detection of the E gene of JEV, 14 samples were found to be positive with a prevalence rate of 4.09%. Age, sex and breed-wise higher cases were found in at the age group above 12 months, sex wise female and breed-wise local pigs. Pig farms less than 500 meters from risk factors like rice field, stagnant water source, wild bird exposure to farm and mosquito exposure at farm/ bite to pigs, found to be more numbers of JE cases. Interpretation & conclusion: Molecular epidemiology of JE in pigs, and humans; positive at Lakhimpur recommend the need for uninterrupted surveillance of this virus in pigs specially those areas where pig population is more and all risk factors are present.

Japanese encephalitis presenting as transverse myelitis: An uncommon presentation

Japanese Encephalitis Virus (JEV) is the main cause of viral encephalitis in South East Asia. Commonly, it presents as an acute encephalitic syndrome with fever, headache, seizures, and altered sensorium as clinical manifestations. However, there can be atypical presentations such as acute transverse myelitis (ATM) as the initial manifestation. Clinicians should be aware of such possibilities and myelitis due to the JE virus should be considered as a differential in children presenting with encephalomyelitis

Outbreaks and Sporadic Cases of Japanese Encephalitis in the State of Odisha, India: Outcome of 7 Years of Laboratory Surveillance

Acute encephalitis syndrome (AES) is a major public health challenge in India. We report here the epidemiology of sporadics and outbreaks of Japanese Encephalitis (JE) in Odisha state during 2012–2018. A total of 4235 AES cases (sporadics – 3394, outbreak cases – 841) recorded including 42 outbreaks; majority (n = 18) of which were during 2016. Overall JE virus (JEV) positivity was 11.78% (outbreak cases – 24.5%, sporadic cases – 8.6%). Age ≤15 years were largely affected during outbreaks, while 16–60 years population was dominant among sporadics. The major outbreak (2016) involved 336 patients from a tribal dominated district, spread over 173 villages. JEV seropositivity was high (43.45%) with 28.57% mortality. Epidemiological linkage with pig rearing was documented through JEV neutralizing antibodies in 50% of pig serum samples. Although the postvaccination period (2017–18) showed increase in AES case reporting but low JE proportion. Ongoing surveillance and preparedness of the health system would be of importance, especially in tribal‑dominated districts.

ACUTE ENCEPHALITIS SYNDROME IN A TERTIARY CARE SETTING WITH SPECIAL REFERENCE TO JAPANESE ENCEPHALITIS: AN OBSERVATIONAL STUDY IN ASSAM, INDIA

Acute Encephalitis Syndrome (AES) is a major public health problem and Japanese Encephalitis (JE) is one of the most important causes of AES. Therefore, it is crucial to know the etiology of AES for patient management and decision making. The present study aimed to assess the morbidity and mortality profile of AES/JE patients admitted in tertiary care setting. An observational prospective cross-sectional study was conducted among 140 hospitalized AES patients admitted in Pediatric and Medicine ward of Jorhat Medical College and Hospital (JMCH), Jorhat over a period from August, 2017 to July 2018. Blood serum and cerebrospinal fiuids (CSF) were tested for presence of JE specific IgM antibody by Mac ELISA during acute illness of AES. The data were compiled and analyzed using the IBM SPSS, V23.0. Of the total 140 AES cases, majority (60%) were below 15 years age (p-value 0.180). Significantly higher proportion of AES cases were from rural areas (94.3%) (p-value <0.0001). The male and female ratio was 1.3:1. The most common presenting symptoms in AES patients were fever (100%), change in mental status (100%), seizure (56.4%) and headache (42.9%). Signs of meningeal irritation were present in 69.3% of cases. Around 22.9% AES patients had GCS ? 8. A total 49 (35%) cases were found to be laboratory confirmed JE following detection of JE specific IgM antibody. Among the JE patients, only 4.1% were immunized with SA 14-14-2 vaccine and 14% died before discharge. The complete recoveries were observed in 78% of cases. JE is one of the major causes of AES which is highly prevalent in this part of India. The significant findings in the present study calls for policy decision to combat JE.

First report on the detection of Japanese encephalitis virus in fruit bats from India

Japanese encephalitis (JE) is a mosquito borne viral zoonotic disease and JE virus (JEV) is responsible for causing several children deaths every year in India. Since 1978, cases of JE have been reported from Gorakhpur district of Uttar Pradesh state annually. The knowledge on the role played by wildlife reservoirs in the sylvatic transmission and maintenance of JE virus remains limited. Bats are reservoir hosts for several emerging and re-emerging viral pathogens but their role in zoonotic cycle of JEV has not been elucidated yet. In Gorakhpur district of Uttar Pradesh, 52 fruit bats were found dead on 26 May 2020. The post-mortem report of the bat samples conducted at the Indian Veterinary Research Institute stated that the bats died due to brain hemorrhage, caused by excessive heat. The brain tissue samples of the bats were subjected to investigation using molecular techniques to determine the presence of JEV. The present work reports for the first time the detection of JEV in brain samples of bats from India. The viral load ranging from 8 to 18 copies/reaction was detected in brain samples by TaqMan real Time RT-PCR. The low viral load might be the reason for the absence of apparent clinical signs in bats and suggests the probable role of fruit bats in maintaining the JEV in nature.

Spatiotemporal Epidemiology of Japanese Encephalitis Cases of Dibrugarh district from 2014 to 2018: A Hospital Record-Based Descriptive Study

Background: Since 1976, several JE outbreaks have been reported from most of the districts of Assam. Objectives: The present study aims to conduct a descriptive and spatial analysis to understand the spatiotemporal distribution of JE cases of Dibrugarh district. Methods: Spatiotemporal distribution of JE cases from 2014 to 2018 at village level was described in maps using Geographical Information System. Spatial association between JE reporting places in the study area has been analyzed using spatial statistics analytical techniques. Temporal distribution of JE cases from 2014 to 2018 for different variable were described in tables. Results: During the period 2014–2018, incidence rate of JE cases ranged between 2.7/100,000 and 5.9/100,000 population and highest case fatality rate was 18.3% in 2014. Highest numbers of JE cases were reported in the age group 0–10 years. Most of the JE cases were from rural areas (84.2%). There was a seasonal pattern of JE which peaked in July. There were hotspots around Dibrugarh Municipality area, Duliajan oil town, Hatiali gaon, Naharkatiya chah bagicha, Nagaon Dhadumia gaon, and Nahortoli Tea Estate. Conclusion: On the basis of the study, JE hotspots can be identified that would help health authorities to further investigate and identify the factors responsible for its occurrence.

Alleviating Japanese encephalitis virus infection with multiple receptor tyrosine kinase inhibitor sunitinib / 中国热带医学

@#Abstract: Objective　To evaluate the effects of sunitinib on Japanese encephalitis virus (JEV) infection in vitro and vivo. Methods　The 4-week-old BALB/c mice infected with JEV by intraperitoneal injection. The infected mice were treated with sunitinib for 5 days and 10 days respectively. After that, the change of weight and survival rate were evaluated continuously. The viral load variation in mice brain were detected by qRT-PCR. Indirect immunohistochemical staining assay (IFA) was used to detect the number and distribution of CD4+/CD8+T cells in mouse brain. IFA was also used to observe the expression of virus E protein in the brain of mice. Vero cells were infected with JEV in vitro and given a certain concentration of sunitinib to observe the cell survival status. The expression of virus E protein in cells was detected by IFA. Results　Continuous administration of sunitinib significantly improved the survival rate of infected mice. Survival rate and body weight changes showed that the 5-day's administration strategy was significantly better than the 10-day's administration strategy. The treatment of sunitinib decreased the infiltration of CD4+/CD8+T cells in the brain and reduced the changes of vascular sleeve. However, the variation of viral load and E protein expression in brain were not obvious. The cytopathic effect (CPE) of infected Vero cells were slightly relieved after giving sunitinib, and the expression of E protein was also slightly changed. Conclusion　Sunitinib can significantly reduce the mortality of infected mice, and the 5-day's administration strategy is significantly better than the 10-day's administration strategy. Sunitinib decrease T lymphocyte infiltration in brain of mice, relieve the encephalitis symptoms ,and prolonged the life of mice.

Dengue Encephalopathy or Japanese Encephalitis? Co-Infection or Serologic Cross- Reactivity?

@#Dengue infection has a wide clinical spectrum ranging from asymptomatic presentation to life-threatening severe dengue with multiorgan failure, and increasingly recognized neurological presentation in the past decade. Japanese encephalitis on the other hand is another common mosquitoes-borne flavivirus infection endemic in Southeast Asia, which share some similar clinical features. We report a case of a 38-year-old male patient who presented to us with complaints of fever and acute encephalitis syndrome with positive dengue NS1 antigen, and positive cerebrospinal fluid serologies for both dengue and JE immunoglobulins. Magnetic Resonance Imaging findings were suggestive of encephalitic changes. Co-infection and serology cross-reactivity of these two flaviviruses is not uncommon in countries where both dengue and Japanese encephalitis are endemic, and thus, the treating clinician should have a high index of suspicion if clinical and serological evidence are present whilst treating the patient.

Establishment, validation and application of fluorescence focus assay for rapid titration of Japanese encephalitis virus / 中华微生物学和免疫学杂志

Objective:To establish and validate a fluorescence focus assay (FFA) for rapid titration of Japanese encephalitis virus (JEV) and to evaluate its application in the production of Japanese encephalitis vaccine.Methods:Recombinant JEV non-structural protein 1 (NS1) was expressed in a prokaryotic expression system. After purification, JEV-NS1 was used to immunize rabbits to induce polyclonal antibody. FFA was established with the polyclonal antibody to titer JEV. The accuracy of FFA was validated by comparing with plaque assay, and the specificity, precision, linearity, range and robustness of FFA were also validated. Twenty-eight batches of live-attenuated Japanese encephalitis vaccine were titrated with FFA and plaque assay to analyze the relationship between the two assays.Results:FFA established with polyclonal antibody against JEV-NS1 could be used to titrate JEV, and there was no cross reaction with other viruses (tick-borne encephalitis virus, yellow fever virus, coxsackievirus A2, coxsackievirus A4). Results of the validation tests showed that FFA met the requirement of quality control for live-attenuated Japanese encephalitis vaccine. FFA was more consistency than plaque assay.Conclusions:The established FFA could be used for virus titration in the production of live-attenuated Japanese encephalitis vaccine.

Epidemic characteristics of epidemic Japanese encephalitis and antibody levels in healthy people in Longnan City, Gansu Province from 2015 to 2020 / 中华地方病学杂志

Objective:To understand the epidemic characteristics of epidemic Japanese encephalitis and the antibody level of healthy people in Longnan City, Gansu Province, analyze and evaluate its epidemic risk, and provide scientific basis for future prevention and control of Japanese encephalitis.Methods:By retrospective analysis, the data of Japanese encephalitis cases in Longnan City from 2015 to 2020 were collected from the "Japanese Encephalitis Monitoring Information Report Management System" of the "China Disease Prevention and Control Information System", and the distributions of the cases(time, region and population distribution) were statistically described and analyzed. In 2018, the cluster stratified sampling method was adopted to select Li County and Xihe County with higher incidence rate of Japanese encephalitis in Longnan City, and Wudu District and Hui County with lower incidence rate as monitoring sites, and 3 administrative villages (communities) were selected from each monitoring site to collect blood samples from healthy people to detect the level of Japanese encephalitis IgG antibodies.Results:From 2015 to 2020, a total of 261 cases of Japanese encephalitis were reported in Longnan City, with an average annual incidence of 1.66 per 100 000; among them, the number of reported cases in 2017 and 2018 accounted for 82.38% (215/261) of the total number of cases. The incidence of Japanese encephalitis was mainly concentrated in August, accounting for 72.03% (188/261); 9 counties (districts) in Longnan City had reported cases of Japanese encephalitis, and the top 5 counties (districts) with the number of cases were Li County (68 cases), Xihe County (64 cases), Wudu District (40 cases), Kang County (33 cases) and Cheng County (18 cases), accounting for 85.44% (223/261) of the total number of cases. The age of onset of Japanese encephalitis cases was mainly concentrated in the 40 - < 60 years old, accounting for 40.23% (105/261); male to female ratio was 1.00 ∶ 1.14 (122 ∶ 139); the occupation was mainly farmers, accounting for 75.86% (198/261). A total of 887 sera samples from healthy people were tested, and the antibody positive rate was 91.09% (808/887); the difference in antibody positive rate of different age groups was statistically significant (χ 2 = 5.77, P < 0.05); the differences of positive rate of antibodies between different genders and regions were not statistically significant (χ 2 = 0.45, 2.06, P > 0.05). Conclusions:The incidence of Japanese encephalitis in Longnan City is mainly middle-aged farmers, with a high incidence in August each year. After the outbreak of Japanese encephalitis in Longnan City in 2017 and 2018, it has showed a low epidemic trend, and the positive rate of Japanese encephalitis antibody in healthy people is high. It is recommended to carry out regular monitoring of Japanese encephalitis immunization level of healthy people and strengthen the immunization of key populations in time.

Analysis of influencing factors of death of epidemic Japanese encephalitis cases in Longnan City, Gansu Province from 2014 to 2018 / 中华地方病学杂志

Objective:To understand the influencing factors of death of epidemic Japanese encephalitis (EJE) cases in Longnan City of Gansu Province.Methods:In the EJE Monitoring Information Report Management System of the Chinese Disease Prevention and Control Information System, data on EJE cases with onset from 2014 to 2018 and current address in Longnan City were derived. An "Individual Questionnaire of Epidemic Japanese Encephalitis in Longnan City" was designed, retrospective study was conducted on enrolled cases, their information on demographic data, consultation, onset, clinical classification, and chronic underlying diseases were collected, characteristics of EJE cases and death-related factors were analyzed.Results:From 2014 to 2018, a total of 260 EJE cases were reported in Longnan City, and 259 cases completed the questionnaire. Among them, 70 cases (27.0%) were aged ≥60 years old, 67 cases (25.9%) were severe and extremely severe, and 55 cases (21.2%) had chronic underlying diseases. Among 259 EJE cases, 46 cases died, with a fatality rate of 17.8%. After multivariate unconditional logistic regression analysis, age ≥60 years old [odds ratio ( OR)=2.667, 95% confidence interval ( CI): 1.140-6.237], severe and extremely severe ( OR = 2.762, 61.820, 95% CI: 1.053-7.091, 5.149-742.239), and chronic underlying diseases ( OR = 2.489, 95% CI: 1.038-5.964) were risk factors for death in EJE cases. Conclusions:The influencing factors of death of EJE cases in Longnan City are age, clinical classification and chronic underlying diseases. Therefore, we should focus on patients over 60 years old, clinically classified as severe or extremely severe, and suffering from chronic underlying diseases, and strengthen the immunization of EJE vaccine for key populations.

Atorvastatin ameliorates viral burden and neural stem/ progenitor cell (NSPC) death in an experimental model of Japanese encephalitis

Japanese encephalitis virus, a neurotropic flavivirus, causes sporadic encephalitis with nearly 25% fatal casereports. JEV infects neural stem/progenitor cells (NSPCs) and decreases their proliferation. Statin, a commonlyused class of cholesterol lowering drug, has been shown to possess potent anti-inflammatory and neuroprotective effects in acute brain injury and chronic neurodegenerative conditions. Here, we aimed to check theefficacy of atorvastatin in alleviating the symptoms of Japanese encephalitis (JE). Using BALB/c mouse modelof JEV infection, we observed that atorvastatin effectively reduces viral load in the subventricular zone (SVZ)of infected pups and decreases the resultant cell death. Furthermore, atorvastatin abrogates microglial activation and production of proinflammatory cyto/chemokine production post JEV infection in vivo. It alsoreduced interferon-b response in the neurogenic environs. The neuroprotective role of atorvastatin is againevident from the rescued neurosphere size and decreased cell death in vitro. It has also been observed that uponatorvastatin administration, cell cycle regulatory proteins and cell survival proteins are also restored to theirrespective expression level as observed in uninfected animals. Thus the antiviral, immunomodulatory andneuroprotective roles of atorvastatin reflect in our experimental observations. Therefore, this drug broadens apath for future therapeutic measures against JEV infection.

Communication and awareness on a new vaccine: a cross-sectional study in a tertiary care hospital of West Bengal

Background: Japanese encephalitis (JE) vaccination in India started in 2006 with SA-14-14-2 live attenuated JE vaccine (JEV) following large outbreaks of JE in some districts of Eastern Uttar Pradesh and Bihar in 2005. Age groups 1-15 yrs are first vaccinated with a single dose of JEV in a campaign mode followed by integration of this vaccine in routine immunization. It is beyond doubt that added to vaccination campaigns, proper awareness on JE can play significant role in controlling the disease.Methods: An observational study with cross sectional design was conducted in Kolkata Medical College and Hospital, Kolkata during JE Vaccination campaign during January, 2018 among 85 respondents, to assess the awareness on JE, among care-givers who brought their children for vaccination at the immunization clinic.Results: It was found that only 37.6% the respondents attending the campaign knew the name of the disease; 17.6% respondents were aware about disease transmission, and 5.9% could state two or more clinical features that might be associated with Japanese Encephalitis. 69.4% had no knowledge of up to what age JE vaccines can be administered; 23.5% said it can be administered till the beneficiaries attain fifteen years of age.Conclusions: IEC activities during JE vaccination campaign was not able raise awareness on JE to the desired level. However beneficiaries were informed about service availability and could be mobilised to come for vaccination.

Comparson of the immunogenicity of genotypeⅠJapanese encephalitis virus subunit vaccine candidate antigens / 生物工程学报

To screen the best genotypeⅠJapanese encephalitis virus subunit vaccine candidate antigens, the prMEIII gene, the polytope gene and the prMEIII-polytope fusion gene of the GenotypeⅠJapanese encephalitis virus GS strain were cloned into prokaryotic expression vector pET-30a. The recombinant proteins were obtained after the induction and purification. The prepared recombinant proteins were immunized to mice, and the immunogenicity of the subunit vaccine candidate antigens was evaluated through monitoring the humoral immune response by ELISA, detecting the neutralizing antibody titer by plaque reduction neutralization test, and testing the cell-mediated immune response by lymphocyte proliferation assay and cytokine profiling. The recombinant proteins with the molecular weights of 35 (prMEIII), 28 (polytope antigen) and 57 kDa (prMEIII-polytope) induced strong humoral and cellular immune responses in mice. Compared with prMEIII-polytope and polytope proteins, the prMEIII protein induced a significant expression of IL-2 and IFN-γ (P0.05). The study suggests that the prMEIII protein can be used for the development of the Japanese encephalitis virus subunit vaccine.

Japanese encephalitis virus: Biological clones from a clinical isolate quasispecies show differing neurovirulence in vitro and in a mouse model

@#The Japanese encephalitis virus (JEV), a leading cause of encephalitis, exists as quasispecies in clinical isolates. Using a limiting dilution method combined with immunohistochemistry to detect viral antigens, 10 biological clones were isolated and purified from a clinical JEV isolate (CNS138/9) derived from an autopsy brain. These biological clones were tested for neurovirulence in SK-N-MC and NIE-115 neuronal cells, and a 2-week-old, footpad-infected, JE mouse model. Nine clones were found to be neurovirulent; one clone neuroattenuated. Although further studies are needed to determine genotypic differences, if any, in these clones, the limiting dilution purification and neurovirulence testing methods described herein should be useful for phenotypic studies of quasispecies of neurotropic viruses in general, and JEV and other flaviviruses in particular.

A Retrospectives Study of Seroprevalence of Japanese Encephalitis in Patients Attending Microbiology Department of MGM Medical College, Jamshedpur

Background: Japanese Encephalitis is one of the mostimportant causes of viral encephalitis worldwide, with anestimated 50,000 cases and 15,000 deaths annually. Thepresent study was undertaken to investigate theSeroprevalence and Seasonal Trend of Japanese Encephalitisin Jamshedpur.Methods: It was a hospital-based retrospective studyconducted from August 2011 to December 2017. A total of 571consecutive non-repetitive patients, satisfying the clinical casedefinition of JE as per the WHO guidelines, were included inthe study. Cerebrospinal fluid (CSF) and serum samples weretested for JEV-specific IgM antibodies by the NIV JE IgMCapture ELISA Kit.Results: Out of which 166/571 (29.07%) were JE positivediagnosed by IgM Mac ELISA antibody kit. We have observedthat in a period of six years, the JE positivity rate hassignificantly reduced from 39.84% in 2011 to 7.29% in 2017.Conclusions: A declining trend of JE was seen in this study,however further research work needs to be done to lookfor non-JE causes of JE. Surveillance & effective vaccinationshould be carried out regularly for early detection of animpending outbreak and to initiate timely preventive and controlmeasures.

Prevalence Status of Antibodies of Japanese Encephalitis in Pigs in Peri-Urban Area of Chennai

Japanese Encephalitis (JE) is a mosquito borne viral zoonotic disease caused by the Japanese Encephalitis Virus (JEV) of Flaviviridae family and it is one of the leading causes of acute encephalitis syndrome in Asian countries. This study was conducted between November 2018 and February 2019 to understand the dynamic status of sero-prevalence of Japanese encephalitis in pigs in peri-urban areas of Chennai using indirect ELISA. A total of 241 sera samples of pigs was collected from peri-urban areas of Chennai and subjected to indirect IgG capture commercial ELISA kit for screening for JEV antibodies. The overall prevalence of JEV antibodies was found as 35.48% which showed the circulation of JEV antibodies in swine population in peri-urban areas of Chennai indicating that pigs still act as amplifier hosts for vectors for the transmission of the disease in Peri-urban areas of Chennai

Effects of different salinity levels on larval growth and development of disease vectors of Culex species

Aim: To determine species distribution of mosquitoes in coastal brackish wetlands and in paddy field area of Kerala along with the effect of increased salinity on the development and survival of major Japanese encephalitis vectors. Methodology: Mosquito survey was carried out in different sites of coastal brackish water as well as in paddy fields of Alappuzha district. First instar larvae were reared until adult emergence at different constant saline water. Each individual was monitored daily for mortality. Larvae were placed in a plastic container with 200 ml distilled water, which served as controls. Counts of larvae, pupae and adults were recorded every 24 hr up to adult emergence. Results: The collected mosquitoes were Culex tritaeniorhynchus, Cx. gelidus, Cx. sitiens, Cx. quinquefasciatus, Cx. bitaeniorhynchus and Anopheles vagus. During summer season, Cx. sitiens (92.85%) was the predominant species followed by Cx. tritaeniorhynchus (2.97%) and Cx. gelidus (2.25%). In saline tolerant study, the maximum adult emergence occurred at 5 parts per thousand. The number of larvae surviving till adult stage decreased progressively with increased salinity. The wing size decreased significantly with increasing salinities, except those reared in 5ppt. Interpretation: The present study demonstrates that these three mosquitoes have the ability to oviposit and breed in brackish water. The study also reveals the health risks associated with vector mosquitoes developing and their frequency of abundance in brackish water, particularly in the context of rising sea levels due to global warming.