SEROPREVALENCE OF INFECTIOUS BOVINE RHINOTRACHEITIS (IBR) IN NORTH EASTERN (NE) STATES OF INDIA

Infectious bovine rhinotracheitis (IBR) is an infectious disease caused by BoHV-1 and belongs to the Herpesviridae family. IBR is endemic in India including north eastern states of the country. Hence the study was undertaken to understand the seroprevalence of IBR in north eastern parts of the country. A total of 3125 cattle (Holstein Friesian crossbred) serum samples from 35 districts of five north eastern states (Assam, Manipur, Meghalaya, Mizoram, and Sikkim) of India were screened for infectious bovine rhinotracheitis (IBR) virus antibodies using Avidin biotin ELISA.  A two-stage random sampling methodology was followed for the collection of samples. Results from the present study revealed that the overall seropositivity was reported around 29.50% while the highest and lowest seropositivity of 43.39% and 16.66% were reported in the states of Sikkim and Assam respectively, followed by Mizoram (42.16%), Manipur (29.86%) and Meghalaya (27.40%). Cattle of higher age groups showed the highest seropositivity compared to younger ones. A higher percent of IBR antibodies in cattle of NE states is a cause of concern and a detailed study on IBR prevalence comprising of a large number of the bovine population need to be undertaken

Spatial and temporal analysis of haemorrhagic septicaemia outbreaks in India over three decades (1987–2016)

Haemorrhagic septicaemia (HS) is an economically important disease affecting cattle and buffaloes and the livelihoods of small-holder farmers that depend upon them. The disease is caused by Gram-negative bacterium, Pasteurella multocida, and is considered to be endemic in many states of India with more than 25,000 outbreaks in the past three decades. Currently, there is no national policy for control of HS in India. In this study, we analysed thirty year (1987–2016) monthly data on HS outbreaks using different statistical and mathematical methods to identify spatial variability and temporal patterns (seasonality, periodicity). There was zonal variation in the trend and seasonality of HS outbreaks. Overall, South zone reported maximum proportion of the outbreaks (70.2%), followed by East zone (7.2%), Central zone (6.4%), North zone (5.6%), West zone (5.5%) and North-East zone (4.9%). Annual state level analysis indicated that the reporting of HS outbreaks started at different years independently and there was no apparent transmission between the states. The results of the current study are useful for the policy makers to design national control programme on HS in India and implement state specific strategies. Further, our study and strategies could aid in implementation of similar approaches in HS endemic tropical countries around the world

Contrasting selective patterns across the segmented genome of bluetongue virus in a global reassortment hotspot

For segmented viruses, rapid genomic and phenotypic changes can occur through the process of reassortment, whereby co-infecting strains exchange entire segments creating novel progeny virus genotypes. However, for many viruses with segmented genomes, this process and its effect on transmission dynamics remain poorly understood. Here, we assessed the consequences of reassortment for selection on viral diversity through time using bluetongue virus (BTV), a segmented arbovirus that is the causative agent of a major disease of ruminants. We analysed ninety-two BTV genomes isolated across four decades from India, where BTV diversity, and thus opportunities for reassortment, are among the highest in the world. Our results point to frequent reassortment and segment turnover, some of which appear to be driven by selective sweeps and serial hitchhiking. Particularly, we found evidence for a recent selective sweep affecting segment 5 and its encoded NS1 protein that has allowed a single variant to essentially invade the full range of BTV genomic backgrounds and serotypes currently circulating in India. In contrast, diversifying selection was found to play an important role in maintaining genetic diversity in genes encoding outer surface proteins involved in virus interactions (VP2 and VP5, encoded by segments 2 and 6, respectively). Our results support the role of reassortment in driving rapid phenotypic change in segmented viruses and generate testable hypotheses for in vitro experiments aiming at understanding the specific mechanisms underlying differences in fitness and selection across viral genomes

Multiple Origins of Foot-and-Mouth Disease Virus Serotype Asia 1 Outbreaks, 2003–2007

Viruses in 6 genetic groups have caused recent outbreaks in Asia

Full-genome sequencing as a basis for molecular epidemiology studies of bluetongue virus in India

Since 1998 there have been significant changes in the global distribution of bluetongue virus (BTV). Ten previously exotic BTV serotypes have been detected in Europe, causing severe disease outbreaks in naïve ruminant populations. Previously exotic BTV serotypes were also identified in the USA, Israel, Australia and India. BTV is transmitted by biting midges (Culicoides spp.) and changes in the distribution of vector species, climate change, increased international travel and trade are thought to have contributed to these events. Thirteen BTV serotypes have been isolated in India since first reports of the disease in the country during 1964. Efficient methods for preparation of viral dsRNA and cDNA synthesis, have facilitated full-genome sequencing of BTV strains from the region. These studies introduce a new approach for BTV characterization, based on full-genome sequencing and phylogenetic analyses, facilitating the identification of BTV serotype, topotype and reassortant strains. Phylogenetic analyses show that most of the equivalent genome-segments of Indian BTV strains are closely related, clustering within a major eastern BTV ‘topotype’. However, genome-segment 5 (Seg-5) encoding NS1, from multiple post 1982 Indian isolates, originated from a western BTV topotype. All ten genome-segments of BTV-2 isolates (IND2003/01, IND2003/02 and IND2003/03) are closely related (>99% identity) to a South African BTV-2 vaccine-strain (western topotype). Similarly BTV-10 isolates (IND2003/06; IND2005/04) show >99% identity in all genome segments, to the prototype BTV-10 (CA-8) strain from the USA. These data suggest repeated introductions of western BTV field and/or vaccine-strains into India, potentially linked to animal or vector-insect movements, or unauthorised use of ‘live’ South African or American BTV-vaccines in the country. The data presented will help improve nucleic acid based diagnostics for Indian serotypes/topotypes, as part of control strategies

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Not AvailableThe 3A region of foot-and-mouth disease virus has been implicated in host range and virulence. Here we analyzed the 3A region of serotype A virus in view of the emergence of a variant group in India with an amino acid deletion at an antigenically critical position of capsid protein, VP3. The 3A region exhibited extreme variability with 38% of the amino acid positions showing substitutions and the C-terminal third (127-151) region was most flexible. Genotype inclusive grouping of type A foot-and-mouth disease virus as observed in 1D region based phylogeny was much less apparent at 3A region possibly due to independent evolution of nonstructural and structural protein coding regions. Akin to the 1D region, the VP3(59)-deletion group maintained its phylogenetic distinctness even at the 3A region and was found to be diverging with time. Twelve lineage specific signature amino acid residues, of which four were identified to be experiencing positive selection, indicates fixation of advantageous mutations in a lineage specific manner. Six positions, all located in the hypervariable C-terminal third, were identified to be under positive selection and were presumed to be imparting the virus certain advantage accounting for its adaptability to wide host spectrum and rapid dissemination. A significant change of Q(44)H was noted only in the older lineage (VIIb) of the deletion group at a position where Q(44)R mutation is associated with guinea pig adaptation. As this site has been detected to be under positive selection, such a lineage specific substitution is thought to have imparted certain temporary advantage to the virus during its possible adaptation in wild or some understudied domestic hosts and must not have seriously compromised fitness upon readaptation in bovines. A conserved hydrophobic transmembrane domain from position 59 to 76 could be predicted which possibly anchors 3A to intracellular membranes for successful interaction with RNA replication complex.Not Availabl

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Not AvailableGenotype inclusive grouping of Indian type A isolates as observed in 1D region based phylogeny was distorted at complete Lpro region, where the VP359-deletion group lineages of genotype VII clustered away from both genotypes VII and VI, confirming its uniqueness and independent evolution of Lpro and 1D region. Akin to the 1D region, this deletion group is gradually diverging genetically even at L region forming more number of lineages and inter-lineage distance at L region is considerably more than that for 1D region. The deletion group is restricted to India only as none of the exotic sequences clustered within this group. Notably, L protein exhibited variability comparable to external capsid proteins as evident from its high dN/dS ratio (0.105), number of variable amino acid positions (41%), low Ts/Tv ratio (3.47) and alignment revealed N-terminal region, β2 sheet and C-terminal extension to be extremely variable. Basic residues at P1, P3 and only leucine at P2 were predicted to provide an optimum autocatalytic cleavage site at L/P1 junction. All of the eight sites identified to be under positive selection revealed aa substitutions of varied physicochemical properties and at two positions lineage specific signatures were observed, which supports the contention that lineages are evolving under differential selection pressure to adapt to the varied ecological environment.Not Availabl

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Not AvailableYears of molecular epidemiological surveillance has revealed co-circulation of two antigenically divergent genotypes of foot and mouth disease virus serotype A in India. Genotype differentiating RT-PCR and sandwich ELISA were developed as fast, cost-effective and user-friendly alternatives to 1D region based phylogeny for detection and differentiation of genotype VI and VII. The RT-PCR assay targeting 1D region was found to be more sensitive and authentic in distinguishing genotypes than sandwich ELISA. These assays promise to be reliable tools in the epidemiological investigation of foot and mouth disease in the country.Not Availabl

Exploring the Impact of Climate Variables on Livestock Anthrax Outbreaks: A Machine Learning Approach

Anthrax, a globally significant disease, poses substantial threats to both livestock and human populations. Timely identification of anthrax outbreaks is paramount to mitigate its impact on animal health, human health, and public safety. This study aims to construct a predictive model for livestock anthrax disease occurrence. By leveraging the potential of advanced Machine-Learning techniques, we projected the likelihood of anthrax outbreaks across India, through incorporating a diverse set of meteorological, and remote sensing parameters. The ultimate goal is to establish a spatial risk map that can serve as an early warning system, aiding in the anticipation and management of future anthrax outbreaks in India's livestock population. Our analysis revealed elevated risk zones for anthrax outbreaks in the southern and north-eastern regions of India, contrasting with medium to low-risk areas in the central parts. Notably, Enhanced Vegetation Index (EVI), Normalized Difference Vegetation Index (NDVI), rainfall, soil moisture, and wind speed emerged as pivotal variables driving the model's predictive accuracy. Among the employed models, the random forest, adaptive boosting, and classification tree analysis approaches showcased superior performance in livestock anthrax risk assessment. The risk map was generated using significant variables by exploiting best fitted models. These findings hold profound implications for policymakers, guiding the targeted deployment of control strategies against anthrax outbreaks. The dynamic risk maps generated through this study enhance public awareness, equipping decision-makers with vital insights for informed action. By spotlighting risk management endeavours, these maps further enhance governance and risk mitigation efforts