Apurba Sarkar

Introduction From 2020, with advent of COVID-19 pandemic, Tripura has experienced SARS-CoV-2 viral evolution in accordance with other parts of India. Since January 2022, the Omicron variant of SARS-CoV-2 virus became the predominant lineage circulating in India and neighboring countries. This study characterizes the viral genome of the omicron variant circulating in the state since its inception to June, 2023. Methods and results The current study was performed on nasopharyngeal and oropharyngeal samples received from the various departments of AGMC, as well as eight district hospitals from Tripura. The positive samples with a cycle threshold value of 25 or less for the E and/or N gene were considered for whole genome sequencing using Illumina Miseq NGS platform. Majority of the sequences belonged to Clade 21 L, with BA.5.2 being the major sub variant detected during the study period. Majority of the mutations were detected in the Spike protein region, including L24-, P25-, P26-, V213G, G339D, S371F, S373P, S375F, T376A, D405N, R408S, K417N, S477N, T478K, Q498R, Y505H, Q954H and N969K. All the sequences uniquely showed the mutations A27S and G142D in N terminal domain in Spike protein, not being reported from other Indian sequences like BA.5 variants. T9I, A63T and P13L were major substitutions in E, M and N protein regions respectively. Escape of mutants from vaccine induced immunity was mostly observed in BA.2 sub variants, majority endowed with the triplet mutation of K417N + E484K + N501Y. Conclusion The current study indicates that Omicron variants circulating in the state of Tripura is comparable to other regions of India and the neighbouring country of Bangladesh. Genetic mutations increasing viral transmissibility have been identified in the circulating viral genomes.

For the vast majority of people on earth, wheat is a primary staple food crop. It is one of the most vulnerable crops, the production of which significantly suffers from the harmful effects of climate change. As the predicted increase in global temperature is supposed to jeopardize production, wheat improvement towards heat stress-resilience has gained pivotal importance. The large and complex allohexaploid wheat genome represents a genetic puzzle, where deciphering any trait-genetics is always challenging. Fortunately, the advancement in the ‘omics’ approach has paved the way for solving these issues in a multidisciplinary convergent manner. The approach has significantly contributed towards the complex molecular mechanisms of the heat stress tolerance in wheat. In the recent past, salient attainments have been observed in exploring heat tolerance mechanisms in wheat addressed through omics technologies. All these approaches have identified some of the key regulators behind this complex trait, the conglomeration of which is definitely promising for achieving heat tolerant cultivars. Besides, the epigenetic regulation of this important trait as well as the significant achievements in developing heat tolerant lines through a transgenic approach has been enumerated. This summarized review of an issue of global importance should enlighten the understanding of the complex regulation of heat tolerance mechanism in wheat, which is a prerequisite for the development of stable heat tolerant wheat cultivars in near future. Here we discussed current research on the genetic and molecular variables that alter one's ability to tolerate heat, including the effects of epigenetic regulation. At the end, we concluded the review by discussing integrative methods for enhancing heat tolerance through the use of current germplasm, such as contemporary cultivars, landraces, and related species.

The aetiology of non-malaria vector-borne diseases in malaria-endemic, forested, rural, and tribal-dominated areas of Dhalai, Tripura, in north-east India, was studied for the first time in the samples collected from malaria Rapid Diagnostic Kit negative febrile patients by door-to-door visits in the villages and primary health centres. Two hundred and sixty serum samples were tested for the Dengue NS1 antigen and the IgM antibodies of Dengue, Chikungunya, Scrub Typhus (ST), and Japanese Encephalitis (JE) during April 2019–March 2020. Fifteen Dengue, six JE, twelve Chikungunya, nine ST and three Leptospirosis, and mixed infections of three JE + Chikungunya, four Dengue + Chikungunya, three Dengue + JE + Chikungunya, one Dengue + Chikungunya + ST, and one Dengue + ST were found positive by IgM ELISA tests, and four for the Dengue NS1 antigen, all without any travel history. True prevalence values estimated for infections detected by Dengue IgM were 0.134 (95% CI: 0.08–0.2), Chikungunya were 0.084 (95% CI: 0.05–0.13), Scrub were 0.043 (95% CI: 0.01–0.09), and Japanese Encephalitis were 0.045 (95% CI: 0.02–0.09). Dengue and Chikungunya were associated significantly more with a younger age. There was a lack of a defined set of symptoms for any of the Dengue, Chikungunya, JE or ST infections, as indicated by the k-modes cluster analysis. Interestingly, most of these symptoms have an overlapping set with malaria; thereby, it becomes imperative that malaria and these non-malaria vector-borne disease diagnoses are made in a coordinated manner. Findings from this study call for advances in routine diagnostic procedures and the development of a protocol that can accommodate, currently, in practicing the rapid diagnosis of malaria and other vector-borne diseases, which is doable even in the resource-poor settings of rural hospitals and during community fever surveillance.

Background: Spectrum of COVID-19 disease ranges from asymptomatic or mild symptomatic to life threatening cases. Population based sero-epidemiological studies are useful for assessing the magnitude of COVID-19 infection in a geographic area and it is helpful for planning control measures. Objectives: To estimate the sero-prevalence of SARS CoV-2 antibody in the general population of Tripura and to study the factors associated with it. Methodology: This community based cross-sectional study was conducted from 15th October to 14th November 2020 among 4800 subjects selected from the whole state of Tripura, India by probability proportionate to size sampling technique using 30 clusters. Electrochemiluminescence (eCLIA) based assay was used to test the serum samples for SARS-CoV-2 specific antibody. Data entry and analysis was performed using SPSS-25 for windows and sero-prevalence was expressed in percentages. Binary logistic regression model was used for predicting sero-positivity by including the significant factors associated with SARS-CoV-2 infection as found out by univariate analysis. Result: Sero-prevalence of SARS-CoV-2 antibody was found to be 34% among the general population of Tripura and it varied from 42.4% to 19.7% across different districts. Logistic regression model has identified, urban residency (OR: 1.21, 95% CI: 1.03-1.42), ethnic community (OR: 0.55, 95% CI: 0.48-0.64) and literacy (OR: 1.41, 95% CI: 1.13-1.77) as the independent risk factors for SARS-CoV-2 sero-positivity (p<0.05). Conclusion: Approximately one out of three residents of Tripura has already acquired the novel SARS CoV-2 infection. As the threshold required for achieving herd immunity against COVID-19 is not yet known, control measures need to be continued for preventing further spread of disease in the community.