Occupational exposure of cashew nut workers to Kyasanur Forest disease in Goa, India

Computational Exploration of Potential Pharmacological Inhibitors Targeting the Envelope Protein of the Kyasanur Forest Disease Virus

The limitations of the current vaccination strategy for the Kyasanur Forest Disease virus (KFDV) underscore the critical need for effective antiviral treatments, highlighting the crucial importance of exploring novel therapeutic approaches through in silico drug design. Kyasanur Forest Disease, caused by KFDV, is a tick-borne disease with a mortality of 3-5% and an annual incidence of 400 to 500 cases. In the early stage of infection, the envelope protein plays a crucial role by facilitating host-virus interactions. The objective of this research is to develop effective antivirals targeting the envelope protein to disrupt the virus-host interaction. In line with this, the 3D structure of the envelope protein was modeled and refined through molecular modeling techniques, and subsequently, ligands were designed via de novo design and pharmacophore screening, yielding 12 potential hits followed by ADMET analysis. The top five candidates underwent geometry optimization and molecular docking. Notably, compounds L4 (SA28) and L3 (CNP0247967) are predicted to have significant binding affinities of -8.91 and -7.58 kcal/mol, respectively, toward the envelope protein, based on computational models. Both compounds demonstrated stability during 200 ns molecular dynamics simulations, and the MM-GBSA binding free-energy values were -85.26 ± 4.63 kcal/mol and -66.60 ± 2.92 kcal/mol for the envelope protein L3 and L4 complexes, respectively. Based on the computational prediction, it is suggested that both compounds have potential as drug candidates for controlling host-virus interactions by targeting the envelope protein. Further validation through in-vitro assays would complement the findings of the present in silico investigations.

Land system governance shapes tick-related public and animal health risks

Land cover and land use have established effects on hazard and exposure to vector-borne diseases. While our understanding of the proximate and distant causes and consequences of land use decisions has evolved, the focus on the proximate effects of landscape on disease ecology remains dominant. We argue that land use governance, viewed through a land system lens, affects tick-borne disease risk. Governance affects land use trajectories and potentially shapes landscapes favourable to ticks or increases contact with ticks by structuring human-land interactions. We illustrate the role of land use legacies, trade-offs in land-use decisions, and social inequities in access to land resources, information and decision-making, with three cases: Kyasanur Forest disease in India, Lyme disease in the Outer Hebrides (Scotland), and tick acaricide resistance in cattle in Ecuador. Land use governance is key to managing the risk of tick-borne diseases, by affecting the hazard and exposure. We propose that land use governance should consider unintended consequences on infectious disease risk.

Clinical, epidemiological, and molecular investigation of Kyasanur forest disease from Karnataka state, India during 2018-2019

BACKGROUND

In this study, we carried out an investigation of Kyasanur Forest Disease (KFD) suspected human cases reported in Karnataka state, India from December 2018 to June 2019.

METHODS

The clinical samples of KFD suspected cases (n = 1955) from 14 districts of Karnataka were tested for KFD using real-time RT-PCR and IgM ELISA. Further, the KFD-negative samples were tested for IgM antibodies against dengue and chikungunya viruses. Monkey samples (n = 276) and tick pools (n = 11582) were also screened using real-time RT-PCR. KFD-positive samples were further analysed using next-generation sequencing along with clinico-epidemiological analysis.

RESULTS

Of all, 173 (8.8%) cases tested positive for KFD either by real-time RT-PCR (n = 124), IgM ELISA (n = 53) or both tests (n = 4) from seven districts. Among KFD-negative cases, IgM antibody positivity was observed for dengue (2.6%), chikungunya (5.8%), dengue and chikungunya coinfection (3.7%). KFD cases peaked in January 2019 with fever, conjunctivitis, and myalgia as the predominant symptoms and a mortality of 4.6%. Among confirmed cases, 41% received a single dose and 20% received two doses of the KFD vaccine. Of the seven districts with KFDV positivity, Shivamogga and Hassan districts reported KFD viral RNA positivity in humans, monkeys, and ticks. Sequencing analysis of 2019 cases demonstrated a difference of less than 1.5% amino acid compared to prototype KFDV.

CONCLUSION

Although the KFD has been endemic in many districts of Karnataka state, our study confirms the presence of KFDV for the first time in two new districts, i.e. Hassan and Mysore. A comparative analysis of KFDV infection among the KFD-vaccinated and non-vaccinated populations demonstrated an insignificant difference.

Knowledge, Attitudes, and Practices Regarding Ticks, Tick-Borne Diseases, and Ethnomedicine Among an at-Risk Population in Kerala

Tick and tick-borne diseases (TBDs) are increasing annually, and the study of ticks has gained importance after the outbreak of Kyasanur Forest disease (KFD) in the South Western Ghats of India. Wayanad district of Kerala, with the highest tribal population in South India, is a KFD endemic state, owing to the lack of knowledge, attitude, and practice studies on TBDs and ethnomedicines against ticks. This study was carried out to assess their baseline knowledge, attitude, and ethnomedicinal practice against ticks. A structured questionnaire was used to conduct a survey of 499 tribal members living in forest fringe areas. Logistic regression analysis was performed to identify the factors that influence the knowledge, attitude, and practice of tribes on TBDs. More than 70% of the population visit the forests on a regular basis, with 65.7% of the population regularly exposed to tick bites; however, only 47.7% were aware of TBDs. About 47.4% of the respondents took precautions like therapeutics and natural remedies to avoid tick bites. Ten species of medicinal plant belonging to eight different families have been identified from the survey. The tribal population use these plants to repel ticks as well as treat tick bites. From the study, we concluded that the limited in-depth knowledge displayed by the tribes can be strengthened by conducting community programs such as awareness classes on TBD and its control measures. The ethnobotanicals identified can be used to formulate novel tick repellents in the future.

Primates and pandemics: A biocultural approach to understanding disease transmission in human and nonhuman primates

Investigations into zoonotic disease outbreaks have been largely epidemiological and microbiological, with the primary focus being one of disease control and management. Increasingly though, the human-animal interface has proven to be an important driver for the acquisition and transmission of pathogens in humans, and this requires syncretic bio-socio-cultural enquiries into the origins of disease emergence, for more efficacious interventions. A biocultural lens is imperative for the examination of primate-related zoonoses, for the human-primate interface is broad and multitudinous, involving both physical and indirect interactions that occur due to shared spaces and ecologies. I use the case example of a viral zoonotic epidemic that is currently endemic to India, the Kysanaur Forest Disease, to show how biocultural anthropology provides a broad and integrative perspective into infectious disease ecology and presents new insights into the determinants of disease outbreaks. Drawing on insights from epidemiology, political ecology, primate behavioral ecology and ethnoprimatology, this paper demonstrates how human-primate interactions and shared ecologies impact infectious disease spread between human and nonhuman primate groups.

Computational prediction of B and T-cell epitopes of Kyasanur Forest Disease virus marker proteins towards the development of precise diagnosis and potent subunit vaccine

Kyasanur Forest Disease (KFD), also known as 'monkey fever', caused by KFD Virus (KFDV), is a highly neglected tropical disease endemic to Western Ghat region of Karnataka, India. Recently, KFD, which is fatal for both monkeys and humans with a mortality rate of 2-10% has been found to spread from its epicenter to neighboring districts and states also. The current ELISA based KFD detection method is very non-specific due to cross-reactivity with other flaviviruses. Further, presently available formalin-inactivated vaccine has been found to be less effective leading to disease susceptibility and severity. To address these, the present study was aimed at predicting the potent specific B and T-cell epitopes of KFDV immunogenic marker proteins using diverse computational tools aiming at developing precise diagnostic method and an effective subunit vaccine. Here, we have chosen E, NS1 and NS5 proteins as markers of KFDV by taking into account of their differential and non-overlapping sequences with selected arboviruses. Based on the linear and nonlinear epitope prediction tools and important biophysical parameters, we identified three potential linear and ten nonlinear B-cell epitopes. We also predicted T-cell epitope peptides which binds to MHC class-I and class-II receptors for the effective T-cell activation. Thus, our molecular docking and molecular dynamics simulation analysis has identified six different TH-cell epitopes based on the distribution frequency of MHC-II haplotypes in the human population and one TC-cell epitope from NS5 protein that has maximum interaction with class-I MHC. Overall, we have successfully identified potential B and T-cell epitope marker peptides present in the envelope and two non-structural proteins.Communicated by Ramaswamy H. Sarma.

Using mechanistic models to highlight research priorities for tick-borne zoonotic diseases: Improving our understanding of the ecology and maintenance of Kyasanur Forest Disease in India

The risk of spillover of zoonotic diseases to humans is changing in response to multiple environmental and societal drivers, particularly in tropical regions where the burden of neglected zoonotic diseases is highest and land use change and forest conversion is occurring most rapidly. Neglected zoonotic diseases can have significant impacts on poor and marginalised populations in low-resource settings but ultimately receive less attention and funding for research and interventions. As such, effective control measures and interventions are often hindered by a limited ecological evidence base, which results in a limited understanding of epidemiologically relevant hosts or vectors and the processes that contribute to the maintenance of pathogens and spillover to humans. Here, we develop a generalisable next generation matrix modelling framework to better understand the transmission processes and hosts that have the greatest contribution to the maintenance of tick-borne diseases with the aim of improving the ecological evidence base and framing future research priorities for tick-borne diseases. Using this model we explore the relative contribution of different host groups and transmission routes to the maintenance of a neglected zoonotic tick-borne disease, Kyasanur Forest Disease Virus (KFD), in multiple habitat types. The results highlight the potential importance of transovarial transmission and small mammals and birds in maintaining this disease. This contradicts previous hypotheses that primates play an important role influencing the distribution of infected ticks. There is also a suggestion that risk could vary across different habitat types but currently more research is needed to evaluate this relationship. In light of these results, we outline the key knowledge gaps for this system and future research priorities that could inform effective interventions and control measures.

The role of social vulnerability in improving interventions for neglected zoonotic diseases: The example of Kyasanur Forest Disease in India

Forest-based communities manage many risks to health and socio-economic welfare including the increasing threat of emerging zoonoses that are expected to disproportionately affect poor and marginalised groups, and further impair their precarious livelihoods, particularly in Low-and-Middle Income (LMIC) settings. Yet, there is a relative dearth of empirical research on the vulnerability and adaptation pathways of poor and marginalised groups facing emerging zoonoses. Drawing on a survey of 229 households and a series of key-informant interviews in the Western Ghats, we examine the factors affecting vulnerability of smallholder and tribal households to Kyasanur Forest Disease (KFD), an often-fatal tick-borne viral haemorrhagic fever endemic in south India. Specifically, we investigate how different socio-demographic and institutional factors interact to shape KFD vulnerability and the strategies employed by households to adapt to disease consequences. Although surveyed households generally perceived KFD as an important health issue in the study region, there was variability in concern about contracting the disease. Overall results showed that poor access to land (AOR = 0.373, 95% CI: 0.152-0.916), being at or below the poverty line (AOR = 0.253, 95% CI: 0.094-0.685) and being headed by an older person (AOR = 1.038, 95% CI: 1.006-1.071) were all significant determinants of perceived KFD vulnerability. Furthermore, KFD vulnerability is also modulated by important extra-household factors including proximity to private hospitals (AOR = 3.281, 95% CI: 1.220-8.820), main roads (AOR = 2.144, 95% CI: 1.215-3.783) and study location (AOR = 0.226, 95% CI: 0.690-0.743). Our findings highlight how homogenous characterisation of smallholder and tribal communities and the 'techno-oriented' approach of existing interventions may further marginalise the most vulnerable and exacerbate existing inequalities. These findings are important for designing context-specific and appropriate health interventions (including the prioritisation of awareness raising, knowledge networks, livelihood diversification) that enhances the resilience of at-risk social groups within the KFD context. More broadly, our findings highlight how a focus on social vulnerability can help national and international health planners improve health interventions and prioritise among diseases with respect to neglected endemic zoonoses.

Dry- down probe free qPCR for detection of KFD in resource limited settings

Kyasanur Forest Disease is a tick-borne flavivirus is endemic in the Southern India. The recent expansion and resurgence of sporadic outbreaks in southern parts of country is the most important concern. Although only formalin inactivated vaccine is available for treatment with limited efficacy the early detection and timely identification is a only way to prevent spread of cases. If the disease can be identified prior to infection in humans like in forest areas from ticks and vectors the disease spread supposed to be managed quickly. Here we have standardized a single tube ready to use dry-down probe free real time RT-PCR targeted against virus envelope gene for detection of KFDV infection. The assay was standardized in liquid format first, later it was converted into dry-down format with addition of stabilizers with a similar sensitivity and specificity (10RNA Copies/rxn). The sensitivity was comparable to the most widely used and accepted diagnostic platform i.e. TaqMan qRT-PCR. However as the reported assay here omit the need of probes makes it cost effective and dry-down reagents makes more stability to the developed assay in this study if compare to TaqMan qPCR. The assay was evaluated with KFD positive samples and healthy sample panel which revealed high concordance with TaqMan qRT-PCR. Stability was unaffected by temperature fluctuations during transportation even in cold chain free conditions, thus reduce the maintenance of strict cold storage. These findings demonstrated that the reported assay is convenient with 100% sensitivity and specificity to TaqMan qPCR. Thus this assay has the potential usefulness for diagnosis KFDV for routine surveillance in resource limited laboratory settings omitting the use costly and heat sensitive TaqMan qRT-PCR reagents without compromising the sensitivity and specificity of the diagnosis assay.

Co-production of knowledge as part of a OneHealth approach to better control zoonotic diseases

There is increased global and national attention on the need for effective strategies to control zoonotic diseases. Quick, effective action is, however, hampered by poor evidence-bases and limited coordination between stakeholders from relevant sectors such as public and animal health, wildlife and forestry sectors at different scales, who may not usually work together. The OneHealth approach recognises the value of cross-sectoral evaluation of human, animal and environmental health questions in an integrated, holistic and transdisciplinary manner to reduce disease impacts and/or mitigate risks. Co-production of knowledge is also widely advocated to improve the quality and acceptability of decision-making across sectors and may be particularly important when it comes to zoonoses. This paper brings together OneHealth and knowledge co-production and reflects on lessons learned for future OneHealth co-production processes by describing a process implemented to understand spill-over and identify disease control and mitigation strategies for a zoonotic disease in Southern India (Kyasanur Forest Disease). The co-production process aimed to develop a joint decision-support tool with stakeholders, and we complemented our approach with a simple retrospective theory of change on researcher expectations of the system-level outcomes of the co-production process. Our results highlight that while co-production in OneHealth is a difficult and resource intensive process, requiring regular iterative adjustments and flexibility, the beneficial outcomes justify its adoption. A key future aim should be to improve and evaluate the degree of inter-sectoral collaboration required to achieve the aims of OneHealth. We conclude by providing guidelines based on our experience to help funders and decision-makers support future co-production processes.

Clinical and Laboratory Diagnostic Features of Kyasanur Forest Disease: A Study From Wayanad, South India

Background

Kyasanur forest disease (KFD), also known as monkey fever, was first recognized in the Shimoga district of Karnataka, India, in 1957. This study was conceived to address the paucity of medical literature on KFD, to describe the clinical and laboratory features of real-time reverse-transcriptase-polymerase chain reaction (rRT-PCR) confirmed cases of KFD, and to detect any change in the clinical picture and presentation of the disease over the last 30 years.

Aim

The study sought to document the clinical and laboratory features of Kyasanur forest disease (KFD), a tick-borne arboviral disease, now emerging in many parts of southern India.

Material and methods

This was a retrospective study using secondary data of patients with real-time reverse transcription-polymerase chain reaction (rRT-PCR)-confirmed KFD in a secondary care hospital in Wayanad, Kerala, India.

Results

Sixty rRT-PCR-proven KFD patients were included in the study. Commonly noted clinical symptoms were fever (98%), headache (80%), body ache (86%), vomiting (61%), and prostration (83%). Relative bradycardia, hypotension (45%), and oral lesions (23%) were the frequent physical signs. The median total leukocyte count and median platelet count at admission were 2600 per μL and 1.62 per μL, respectively. The median erythrocyte sedimentation rate was 10 mm/hr. Urinary sediments and albuminuria were seen in 66% and 60% respectively. The major complications observed were neurological complications (23%), bleeding manifestations (20%), and persistent shock (20%). The common neurological complications were seizures, altered sensorium, aseptic meningitis, and focal neurological deficits. The case fatality rate in the study was 6.7%.

Conclusions

The clinical picture of a prostrating viral syndrome in an epidemiological setting of KFD with marked leucopenia, moderate thrombocytopenia, low erythrocyte sedimentation rate (ESR), albuminuria, urinary sediments, and moderately elevated transaminases help in making an early diagnosis of KFD. Neurological complications in the initial two weeks are associated with poor outcomes.

Kyasanur Forest Disease, is our surveillance system healthy to prevent a larger outbreak? A mixed-method study, Shivamogga, Karnataka, India: 2019

BACKGROUND

Kyasanur Forest disease (KFD) is a tick-borne zoonosis that is endemic in Karnataka. Against the backdrop of the recent geographical expansion of KFD, indicating the inadequacy of policy and surveillance systems, the present study was performed to evaluate the KFD surveillance system in Shivamogga.

METHODS

US Centers for Disease Control and Prevention guidelines for surveillance system evaluation were followed. Nine attributes of the system towards its objectives were evaluated in a mixed study in Shivamogga.

RESULTS

Two of three medical officers and four of six health staff at the institutions visited were found to be untrained in KFD surveillance. Integrated disease surveillance formats did not capture KFD data. Surveillance (tick, monkey, human) was mostly driven by the Health Department. Some of the critical findings of the evaluations were the absence of an animal and entomological surveillance line list, non-standardized reporting formats for human suspects, varying delays in the time-to-test across laboratories (2-16 days), and a lack of systematic data-sharing practices. Significant issues that emerged in the interview were deforestation with a change in ecosystem dynamics, limited diagnostic capacity, non-availability of point-of-care tests, outdated surveillance guidelines, a confusing surveillance perimeter (5 km), non-existing co-ownership among stakeholders, limited vaccine production capacity, and inadequate operational research.

CONCLUSIONS

The system should consider integrating a One Health approach with defined ownership of activities among stakeholders. Revision of the guidelines is mandatory.

Experiences of Indian Council of Medical Research with tick-borne zoonotic infections: Kyasanur Forest disease & Crimean-Congo haemorrhagic fever in India with One Health focus

Emergence and re-emergence of several pathogens have been witnessed by this century in the form of outbreaks, epidemics and pandemics. In India, the influencing factor that promotes dissemination of emerging and re-emerging viral infections is the biogeographical zones: a megadiverse country, characterized by varied geographical, climatic conditions and ever-changing socio-economical and geopolitical issues. These influence the movement of humans and animals and add layers of complexity for the identification and timely management of infectious diseases. This review focuses on two tick-borne infections: Crimean-Congo haemorrhagic fever (CCHF) and Kyasanur forest disease (KFD). In the last two decades, these viruses have emerged and caused outbreaks in different parts of India. KFD virus was initially identified in 1957 and was known to be endemic in Karnataka State while CCHF virus was first identified during 2010 in Gujarat State, India. These viruses have managed to emerge in new areas within the last decade. With changing epidemiology of these arboviruses, there is a probability of the emergence of these viruses from new areas in future. The investigations on these two diseases under the One Health focus involved early detection, quickly developing diagnostic tools, identifying stakeholders, capacity building by developing collaboration with major stakeholders to understand the epidemiology and geographical spread in domestic animal reservoirs and tick vectors in the affected areas, developing laboratory network, providing diagnostic reagents and biosafety and laboratory diagnosis training to the network laboratories to control these diseases.

Point of care real-time polymerase chain reaction-based diagnostic for Kyasanur forest disease

OBJECTIVES

Due to the remote forest area locations of sporadic cases and outbreaks of Kyasanur forest disease (KFD), rapid diagnosis poses a significant challenge. This study aimed to evaluate the diagnostic performance of Truenat KFD, a simple, rapid and user-friendly point-of-care test for detection of KFD and compare diagnostic accuracy with conventional real-time reverse transcription-polymerase chain reaction (RT-PCR) testing. Truenat KFD can be deployed in a field laboratory setting.

METHODS

The study involved 145 clinical specimens, including human serum, monkey necropsy tissues and tick pool, to validate Truenat KFD (Molbio Diagnostics Pvt.Ltd.) for KFD diagnosis.

RESULTS

We have optimized and validated the microchip-based Truenat KFD (Molbio Diagnostics Pvt.Ltd.) for KFD diagnosis. Point-of-care testing was highly sensitive and specific, with a detection limit of up to 10 copies of KFD viral RNA. Results were comparable with the gold-standard TaqMan and commercially available Altona RealStar AHFV / KFDV real-time RT-PCR assays. Screening results for human, monkey and tick specimens were 100% concordant across the assays.

CONCLUSION

Truenat KFD(Molbio Diagnostics Pvt.Ltd.) was found to be highly sensitive and specific with a significant limit of detection. This point-of-care test would be useful in rapid diagnosis of KFD in remote and/or field settings, quick patient management and control of virus spread.

Assessing the importance of Molecular and Genetic perspectives in Prophesying the KFD transmission risk provinces in the Western Ghats, Kerala, INDIA in context with spatial distribution, Extensive genetic Diversity, and phylogeography

The deadly effects of KFD have been pointed in southern India; however, the infecting regions have been getting larger in recent epochs. People who live or work in regions where KFDV infected tick vectors are present are severely prone to procuring the infection. Being aware of tick vectors and infectious agents' geospatial location is vital to direct sustenance approaches to prevent and manage such infectious diseases as KFD. The present investigation has focussed on the spatial distribution, Extensive genetic Diversity, and phylogeography to forecast the probable KFD disease risk provinces in the Western Ghats. The statistical analysis for diversity indices and community comparison has been performed by using SPSS version 24.0.0 and R software version 3.4.2. The nucleotide sequences of the respective ticks and KFDV were retrieved from NCBI. The first strand of this investigation revealed that, around the world, the Indian province was found to exhibit a maximum range of diversity for tick vectors. The next strands prophesied the KFD transmission risk areas in the Western Ghats region, India, with computational spatial analysis and phylogeography. The final strand exposed the genetic diversity of the KFD virus and the tick vectors in terms of their spatial distribution worldwide.

Update on prevalence and distribution pattern of tick-borne diseases among humans in India: a review

In the present scenario, tick-borne diseases (TBDs) are well known for their negative impacts on humans as well as animal health in India. The reason lies in their increased incidences due to global warming, environmental and ecological changes, and availability of suitable habitats. On a global basis, they are now considered a serious threat to human as well as livestock health. The major tick-borne diseases in India include Kyasanur forest disease (KFD), Crimean-congo hemorrhagic fever (CCHF), Lyme disease (LD), Q fever (also known as coxiellosis), and Rickettsial infections. In recent years, other tick-borne diseases such as Babesiosis, Ganjam virus (GANV), and Bhanja virus (BHAV) infections have also been reported in India. The purpose of this paper is to review the history and the current state of knowledge of tick-borne diseases in the country. The conclusion of this review is extending the requirement of greater efforts in research and government management for the diagnosis and treatment and as well as prevention of these diseases so that tick-borne disease burden should be minimizing in India.

Reviewing the ecological evidence base for management of emerging tropical zoonoses: Kyasanur Forest Disease in India as a case study

Zoonoses disproportionately affect tropical communities and are associated with human modification and use of ecosystems. Effective management is hampered by poor ecological understanding of disease transmission and often focuses on human vaccination or treatment. Better ecological understanding of multi-vector and multi-host transmission, social and environmental factors altering human exposure, might enable a broader suite of management options. Options may include "ecological interventions" that target vectors or hosts and require good knowledge of underlying transmission processes, which may be more effective, economical, and long lasting than conventional approaches. New frameworks identify the hierarchical series of barriers that a pathogen needs to overcome before human spillover occurs and demonstrate how ecological interventions may strengthen these barriers and complement human-focused disease control. We extend these frameworks for vector-borne zoonoses, focusing on Kyasanur Forest Disease Virus (KFDV), a tick-borne, neglected zoonosis affecting poor forest communities in India, involving complex communities of tick and host species. We identify the hierarchical barriers to pathogen transmission targeted by existing management. We show that existing interventions mainly focus on human barriers (via personal protection and vaccination) or at barriers relating to Kyasanur Forest Disease (KFD) vectors (tick control on cattle and at the sites of host (monkey) deaths). We review the validity of existing management guidance for KFD through literature review and interviews with disease managers. Efficacy of interventions was difficult to quantify due to poor empirical understanding of KFDV-vector-host ecology, particularly the role of cattle and monkeys in the disease transmission cycle. Cattle are hypothesised to amplify tick populations. Monkeys may act as sentinels of human infection or are hypothesised to act as amplifying hosts for KFDV, but the spatial scale of risk arising from ticks infected via monkeys versus small mammal reservoirs is unclear. We identified 19 urgent research priorities for refinement of current management strategies or development of ecological interventions targeting vectors and host barriers to prevent disease spillover in the future.

Geospatial clustering, seasonal trend and forecasting of Kyasanur Forest Disease in the state of Goa, India, 2015-2018

Introduction

Five states in India are reporting sporadic outbreaks of Kyasanur Forest Disease (KFD). Goa experienced an outbreak of KFD in 2015. It remains as an important differential diagnosis for tropical fever in the endemic regions. Few studies among neighboring two states (Karnataka and Kerala) have described the epidemiological characteristics of KFD. However, there is no study which describes the same among cases in the state of Goa. Hence, we planned to understand the epidemiology (time, place, and person distribution) of the disease including seasonal pattern with forecasting using zero-inflated negative binomial regression and time series models. We also explored geo-spatial clustering of KFD cases in Goa during 2015–2018 which would help design effective intervention to curb its transmission in Goa.

Results

Blood samples of all suspected cases of KFD during 2015 to 2018 were tested using reverse transcriptase-polymerase chain reaction technique. Reports of these results were periodically shared with the state surveillance unit. Records of 448 confirmed cases of KFD available at the State Integrated Disease Surveillance Programme were analyzed. The mean (SD) age of the patients was 41.6 (14.9) years. Of 143 cases with documented travel history, 135 (94.4%) had history of travel to forest for cashew plucking. Two thirds of cases (66.3%) did not receive KFD vaccine prior to the disease. Case fatality rate of 0.9% was reported. Seasonal peaks were observed during January to April, and forecasting demonstrated a peak in cases in the subsequent year also during January–April persisting till May. Around 40 villages located along the Western Ghats had reported KFD, and affected villages continued to report cases in the subsequent years also. Case density-based geographic maps show clustering of cases around the index village.

Conclusion

Most of the confirmed cases did not receive any vaccination. KFD cases in Goa followed a specific seasonal pattern, and clustering of cases occurred in selected villages located in North Goa. Most of the patients who had suffered from the disease had visited the forest for cashew plucking. Planning for public health interventions such as health education and vaccination campaigns should consider these epidemiological features.

Predicting disease risk areas through co-production of spatial models: The example of Kyasanur Forest Disease in India's forest landscapes

Zoonotic diseases affect resource-poor tropical communities disproportionately, and are linked to human use and modification of ecosystems. Disentangling the socio-ecological mechanisms by which ecosystem change precipitates impacts of pathogens is critical for predicting disease risk and designing effective intervention strategies. Despite the global "One Health" initiative, predictive models for tropical zoonotic diseases often focus on narrow ranges of risk factors and are rarely scaled to intervention programs and ecosystem use. This study uses a participatory, co-production approach to address this disconnect between science, policy and implementation, by developing more informative disease models for a fatal tick-borne viral haemorrhagic disease, Kyasanur Forest Disease (KFD), that is spreading across degraded forest ecosystems in India. We integrated knowledge across disciplines to identify key risk factors and needs with actors and beneficiaries across the relevant policy sectors, to understand disease patterns and develop decision support tools. Human case locations (2014-2018) and spatial machine learning quantified the relative role of risk factors, including forest cover and loss, host densities and public health access, in driving landscape-scale disease patterns in a long-affected district (Shivamogga, Karnataka State). Models combining forest metrics, livestock densities and elevation accurately predicted spatial patterns in human KFD cases (2014-2018). Consistent with suggestions that KFD is an "ecotonal" disease, landscapes at higher risk for human KFD contained diverse forest-plantation mosaics with high coverage of moist evergreen forest and plantation, high indigenous cattle density, and low coverage of dry deciduous forest. Models predicted new hotspots of outbreaks in 2019, indicating their value for spatial targeting of intervention. Co-production was vital for: gathering outbreak data that reflected locations of exposure in the landscape; better understanding contextual socio-ecological risk factors; and tailoring the spatial grain and outputs to the scale of forest use, and public health interventions. We argue this inter-disciplinary approach to risk prediction is applicable across zoonotic diseases in tropical settings.

Seroprevalence and incidence of primary dengue infections among children in a rural region of Maharashtra, Western India

Background

Dengue infections have become a huge threat to public health systems in developing countries. Data on seroprevalence and incidence of dengue infections are lacking from rural regions of India. The objective of present study was to investigate the seroprevalence and incidence of dengue infection utilizing repeated serosurveys from a rural region of Maharashtra, Western India.

Methods

In the present study, 819 children between ages 5 to 15 years from 21 villages in Pune District of Maharashtra, India were sampled in 2014 and 2016. The sera were tested for the presence of dengue specific IgG using an indirect IgG ELISA kit.

Results

Overall seroprevalence of dengue was 15.3% (95% confidence intervals (CI) 12.9–17.8%) in 2014 and 20.5% (95% CI 17.8–23.4%) in 2016. Among the 694 children who were seronegative at baseline (2014), 78 seroconverted. Overall incidence rate of primary dengue was 54.2 infections/1000 children years (95% CI 43.0–67.3). Incidence of primary dengue infection was higher in children from urbanized villages compared to rural villages (Incidence rate ratio (IRR) 2.6 (95% CI 1.3–5.2)). In rural villages, incidence of primary dengue infection was higher in children aged 10 years or above as compared to those aged below 10 years (IRR 9.75 (95% CI 1.21–77.9).

Conclusions

The study provides the incidence rates of primary dengue infections from a rural region of India. More multi centric studies investigating the incidence of dengue will provide accurate estimate of incidence of dengue and help formulate well directed policies. The results also suggest that urbanization and transitions in demographic settings might favour dengue outbreaks in rural regions and these regions need to be targeted for vector control measures.

Historical Expansion of Kyasanur Forest Disease in India From 1957 to 2017: A Retrospective Analysis

A highly infectious tick-borne virus causes Kyasanur Forest disease (KFD), which has been expanding in recent decades in India. Current studies do not provide an updated understanding of the disease trends and its expansion in India. We address this gap in the literature through a detailed review to reveal the annual historic expansion of KFD cases across the span of years from 1957 to 2017. In addition, we explore the factors that may have led to the geographic expansion of KFD. The annual numbers of cases of KFD among humans are estimated using peer-reviewed journal articles, Pro-MED database, historical and archived newspapers, and government reports, technical reports, publications, and medical websites. From 1957 to 2017, there were an estimated 9,594 cases of KFD within 16 districts in India. The most significant human outbreaks of the disease were in the years 1957-1958 (681 cases), 1983-1984 (2,589 cases), 2002-2003 (1,562 cases), and 2016-2017 (809 cases). In 2015, KFD appeared in Goa. In 2016, new cases emerged in Belgaum, a district in Karnataka state, and in the Sindhudurg district in Maharashtra state. The processes by which KFD persists and spreads are not clear, but demographic, socioeconomic, political, and environmental factors seem to play a role.

Epidemiology, Pathogenesis, and Control of a Tick-Borne Disease- Kyasanur Forest Disease: Current Status and Future Directions

In South Asia, Haemaphysalis spinigera tick transmits Kyasanur Forest Disease Virus (KFDV), a flavivirus that causes severe hemorrhagic fever with neurological manifestations such as mental disturbances, severe headache, tremors, and vision deficits in infected human beings with a fatality rate of 3-10%. The disease was first reported in March 1957 from Kyasanur forest of Karnataka (India) from sick and dying monkeys. Since then, between 400 and 500 humans cases per year have been recorded; monkeys and small mammals are common hosts of this virus. KFDV can cause epizootics with high fatality in primates and is a level-4 virus according to the international biosafety rules. The density of tick vectors in a given year correlates with the incidence of human disease. The virus is a positive strand RNA virus and its genome was discovered to code for one polyprotein that is cleaved post-translationally into 3 structural proteins (Capsid protein, Envelope Glycoprotein M and Envelope Glycoprotein E) and 7 non-structural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5). KFDV has a high degree of sequence homology with most members of the TBEV serocomplex. Alkhurma virus is a KFDV variant sharing a sequence similarity of 97%. KFDV is classified as a NIAID Category C priority pathogen due to its extreme pathogenicity and lack of US FDA approved vaccines and therapeutics; also, the infectious dose is currently unknown for KFD. In India, formalin-inactivated KFDV vaccine produced in chick embryo fibroblast is being used. Nevertheless, further efforts are required to enhance its long-term efficacy. KFDV remains an understudied virus and there remains a lack of insight into its pathogenesis; moreover, specific treatment to the disease is not available to date. Environmental and climatic factors involved in disseminating Kyasanur Forest Disease are required to be fully explored. There should be a mapping of endemic areas and cross-border veterinary surveillance needs to be developed in high-risk regions. The involvement of both animal and health sector is pivotal for circumscribing the spread of this disease to new areas.