Infectious Causes of Acute Encephalitis Syndrome in India - Decadal Change and the Way Forward.

The diagnosis and management of encephalitis were previously largely based on clinical grounds and minimal laboratory investigations. Japanese encephalitis (JE) gets considered as the probable diagnosis in most encephalitis cases. However, reports of JE in adults and the elderly are increasing after the JE vaccine introduction among children in 2006. The Nipah virus (NiV) emerged in 2002 and continues to afflict humans in new geographic areas. Many other infections cause encephalitis, including Chandipura, chikungunya, dengue, and West Nile. Significant advances in diagnostic testing like multiplex testing panels and metagenomic approaches along with sequencing have helped in the detection of new etiologies. Recent years have witnessed an increase in climate-sensitive zoonotic diseases with encephalitis. This highlights the importance of the One Health approach in studying the impact of climate change-associated infectious diseases on human health. The government of India's efforts to develop health research infrastructure would help future responses to emerging infectious disease epidemics.

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

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

Effectiveness of Japanese encephalitis vaccination among children in central India.

Japanese encephalitis (JE) disease among children continues in central India despite vaccination implemented in the routine immunization program. Therefore, we planned to estimate the JE vaccination effectiveness among children by undertaking a 1:2 individually-matched population-based case-control study from August 2018 to October 2020. The laboratory-confirmed JE cases aged 1-15 years were enrolled along with neighborhood controls without fever and encephalitis matched on the residence area, age and sex. The JE vaccination history was enquired from parents and verified independently from the vaccination cards available at home and records at health facilities. We enrolled 35 JE cases and 70 matched controls. The vaccination effectiveness of 86.7% (95% confidence interval [CI]: 30.8-94.7) was estimated on the per-protocol analysis of 31 case-control sets. The screening method provided an effectiveness of 89.5% (CI: 78.9-94.7) on using the population vaccination coverage of 90% reported earlier in the same area. In conclusion, JE vaccination offered a moderate level of protection among children in JE medium-endemic central India, similar to reports from high-endemic areas in India. The operational aspects of vaccination program implementation need to be evaluated to assess the impact of vaccination on the disease burden of JE in medium-endemic regions of India.

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

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

Infectious causes of acute encephalitis syndrome hospitalizations in Central India, 2018-20.

BACKGROUND: We enhanced surveillance of hospitalizations of all ages for acute encephalitis syndrome (AES) along with infectious aetiologies, including the Japanese encephalitis virus (JEV). METHODS: From October 2018 to September 2020, we screened neurological patients for AES in all age groups in Maharashtra and Telangana States. AES cases were enrolled at study hospitals along with other referrals and sampled with cerebrospinal fluid, acute and convalescent sera. We tested specimens for non-viral aetiologies viz. leptospirosis, typhoid, scrub typhus, malaria and acute bacterial meningitis, along with viruses - JEV, Dengue virus (DENV), Chikungunya virus (CHIKV), Chandipura virus (CHPV) and Herpes simplex virus (HSV). RESULTS: Among 4977 neurological hospitalizations at three study site hospitals over two years period, 857 (17.2%) were AES. However, only 287 (33.5%) AES cases were eligible. Among 278 (96.9%) enrolled AES cases, infectious aetiologies were identified in 115 (41.4%) cases, including non-viral in 17 (6.1%) cases - leptospirosis (8), scrub-typhus (3) and typhoid (6); and viral in 98 (35.3%) cases - JEV (58, 20.9%), HSV (22, 7.9%), DENV (15, 5.4%) and CHPV (3, 1.1%). JEV confirmation was significantly higher in enrolled cases than referred cases (10.2%) (p < 0.05). However, the contribution of JEV in AES cases was similar in both children and adults. JE was reported year-round and from adjacent non-endemic districts. CONCLUSIONS: The Japanese encephalitis virus continues to be the leading cause of acute encephalitis syndrome in central India despite vaccination among children. Surveillance needs to be strengthened along with advanced diagnostic testing for assessing the impact of vaccination.

Effect of mobile phone signal radiation on epigenetic modulation in the hippocampus of Wistar rat.

Exponential increase in mobile phone uses, given rise to public concern regarding the alleged deleterious health hazards as a consequence of prolonged exposure. In 2018, the U.S. National toxicology program reported, two year toxicological studies for potential health hazards from exposure to cell phone radiations. Epigenetic modulations play a critical regulatory role in many cellular functions and pathological conditions. In this study, we assessed the dose-dependent and frequency-dependent epigenetic modulation (DNA and Histone methylation) in the hippocampus of Wistar rats. A Total of 96 male Wistar rats were segregated into 12 groups exposed to 900 MHz, 1800 MHz and 2450 MHz RF-MW at a specific absorption rate (SAR) of 5.84 × 10-4 W/kg, 5.94 × 10-4 W/kg and 6.4 × 10-4 W/kg respectively for 2 h per day for 1-month, 3-month and 6-month periods. At the end of the exposure duration, animals were sacrificed to collect the hippocampus. Global hippocampal DNA methylation and histone methylation were estimated by ELISA. However, DNA methylating enzymes, DNA methyltransferase1 (DNMT1) and histone methylating enzymes euchromatic histone methylthransferase1 (EHMT1) expression was evaluated by real-time PCR, as well as further validated with Western blot. Alteration in epigenetic modulation was observed in the hippocampus. Global DNA methylation was decreased and histone methylation was increased in the hippocampus. We observed that microwave exposure led to significant epigenetic modulations in the hippocampus with increasing frequency and duration of exposure. Microwave exposure with increasing frequency and exposure duration brings significant (p < 0.05) epigenetic modulations which alters gene expression in the hippocampus.

Activation of endoplasmic reticulum stress in rat brain following low-intensity microwave exposure.

The present study was designed to explore the effects of low-intensity microwave radiation on endoplasmic reticulum stress and unfolded protein response. Experiments were performed on male Wistar rats exposed to microwave radiation for 30 days at 900 MHz, 1800 MHz, and 2450 MHz frequencies on four groups of animal: sham-exposed group, 900 MHz exposed (SAR 5.84 × 10-4 W/kg), 1800 MHz exposed (SAR 5.94 × 10-4 W/kg), and 2450 MHz exposed (SAR 6.7 × 10-4 W/kg) groups. Expressions of mRNA were estimated at the end of exposure in rat brain by real-time quantitative PCR. Microwave exposure at 900, 1800, and 2450 MHz with respective SAR values as mentioned above significantly (< 0.05) altered mRNA expression of transcription factors ATF4, CHOP, and XBP1 in accordance with increasing microwave frequency. The result of the present study reveals that low-intensity microwave exposure at frequencies 900, 1800, and 2450 MHz induces endoplasmic reticulum stress and unfolded protein response.

Effect of Low-Intensity Microwave Radiation on Monoamine Neurotransmitters and Their Key Regulating Enzymes in Rat Brain.

The increasing use of wireless communication devices has raised major concerns towards deleterious effects of microwave radiation on human health. The aim of the study was to demonstrate the effect of low-intensity microwave radiation on levels of monoamine neurotransmitters and gene expression of their key regulating enzymes in brain of Fischer rats. Animals were exposed to 900 MHz and 1800 MHz microwave radiation for 30 days (2 h/day, 5 days/week) with respective specific absorption rates as 5.953 × 10(-4) and 5.835 × 10(-4) W/kg. The levels of monoamine neurotransmitters viz. dopamine (DA), norepinephrine (NE), epinephrine (E) and serotonin (5-HT) were detected using LC-MS/MS in hippocampus of all experimental animals. In addition, mRNA expression of key regulating enzymes for these neurotransmitters viz. tyrosine hydroxylase (TH) (for DA, NE and E) and tryptophan hydroxylase (TPH1 and TPH2) (for serotonin) was also estimated. Results showed significant reduction in levels of DA, NE, E and 5-HT in hippocampus of microwave-exposed animals in comparison with sham-exposed (control) animals. In addition, significant downregulation in mRNA expression of TH, TPH1 and TPH2 was also observed in microwave-exposed animals (p < 0.05). In conclusion, the results indicate that low-intensity microwave radiation may cause learning and memory disturbances by altering levels of brain monoamine neurotransmitters at mRNA and protein levels.

Evaluations of an in-house drug resistance method for HIV-1 drug resistance using ViroSeq™ 2.0 genotyping system as a gold standard.

An in-house method was evaluated for its efficiency to detect the HIV-1 drug resistance mutations. This method was compared with the ViroSeq™ Genotyping System 2.0 (Celera Diagnostics, US) a gold standard. Sixty-five stored plasma samples, previously tested for HIV-1 drug resistance using the ViroSeq™ method were used to evaluate the in-house method. Out of the sixty five plasma samples, sixty were HIV-1 positive clinical samples; four samples from the Virology Quality Assessment (VQA) program and one positive control from the ViroSeq™ kit were used in this study. The sequences generated by the ViroSeq™ and an in-house method showed 99.5±0.5% and 99.7±0.4% (mean±SD) nucleotide and amino acid identity, respectively. Out of 214 Stanford HIVdb listed HIV-1 drug resistance mutations in the protease and reverse transcriptase regions, concordance was observed in 203 (94.9%), partial discordance in 11 (5.1%) and complete discordance was absent. The in-house primers are broadly sensitive in genotyping multiple HIV-1 group M subtypes. The amplification sensitivity of the in-house method was 1000 copies/ml. The evaluation of the in-house method provides results comparable with that of ViroSeq™ method thus, making the in-house method suitable for HIV-1 drug resistance testing in the developing countries.

Initial virologic response and HIV drug resistance among HIV-infected individuals initiating first-line antiretroviral therapy at 2 clinics in Chennai and Mumbai, India.

Human immunodeficiency virus drug resistance (HIVDR) in cohorts of patients initiating antiretroviral therapy (ART) at clinics in Chennai and Mumbai, India, was assessed following World Health Organization (WHO) guidelines. Twelve months after ART initiation, 75% and 64.6% of participants at the Chennai and Mumbai clinics, respectively, achieved viral load suppression of <1000 copies/mL (HIVDR prevention). HIVDR at initiation of ART (P <.05) and 12-month CD4 cell counts <200 cells/µL (P <.05) were associated with HIVDR at 12 months. HIVDR prevention exceeded WHO guidelines (≥ 70%) at the Chennai clinic but was below the target in Mumbai due to high rates of loss to follow-up. Findings highlight the need for defaulter tracing and scale-up of routine viral load testing to identify patients failing first-line ART.

Transmitted HIV drug resistance among HIV-infected voluntary counseling and testing centers (VCTC) clients in Mumbai, India.

A survey for transmitted HIV drug resistance (HIVDR) was conducted according to WHO guidelines among clients newly diagnosed with HIV-1 infection at two voluntary counseling and testing centers (VCTC) in Mumbai. HIVDR testing was performed using the ViroSeq RT-PCR method (Abbott). Out of 50 successfully amplified and sequenced specimens, analysis of the first 34 consecutively collected specimens revealed no nucleoside reverse transcriptase inhibitor, nonnucleoside reverse transcriptase inhibitor, or protease inhibitor mutations from the 2007 WHO list of mutations for surveillance of transmitted HIVDR, indicating that the prevalence of transmitted HIVDR to all three drug classes was <5% among recently infected VCTC clients in Mumbai. The phylogenetic analysis revealed that all samples belonged to HIV-1 subtype C. Continued ART program monitoring and further evaluation of transmitted HIV drug resistance in coming years are essential in Mumbai as well as in other regions of the country in which ART is being scaled up rapidly.