Kyasanur Forest Disease Research Articles

Does the rise in cases of Kyasanur forest disease call for the implementation of One Health in India?

The viral hemorrhagic illness known as Kyasanur forest disease (KFD), also referred to as monkey fever, is transmitted by ticks. The etiological agent, which was formerly isolated from monkeys, is Kyasanur forest disease virus (KFDV), an RNA virus belonging to the family Flaviviridae. Since 1957, India has reported 400–500 cases annually, with a case fatality rate of 1–3%. Shiroma, Chikkamagalore, Uttara Kannada, Dakshina Kannada, and Udupi are the five regions in Karnataka, India where KFD is highly prevalent, with around 3263 notified cases reported between 2003 and 2012, of which 823 cases were laboratory confirmed.The symptoms of monkey fever can range from mild sickness to severe neurological sequelae. Currently, prophylaxis involves administration of formalin-inactivated tissue culture vaccine. Despite the continuing vaccination programs in endemic areas for KFD, new cases are being reported. The current availability and effectiveness of the vaccine are not enough to provide protective immunity and thus prevent new outbreaks.Our study examined the known literature, knowledge gaps, and host responses associated with KFD. There is a need for robust vector control, public awareness campaigns, mass vaccination programmes, a full understanding of the eco-epidemiological elements of the disease, and implementation of a One Health program. These could all support prevention and management protocols, and thus help to address the issue.

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.

Differences in Genetic Diversity of Mammalian Tick-Borne Flaviviruses.

The genetic diversities of mammalian tick-borne flaviviruses are poorly understood. We used next-generation sequencing (NGS) to deep sequence different viruses and strains belonging to this group of flaviviruses, including Central European tick-borne encephalitis virus (TBEV-Eur), Far Eastern TBEV (TBEV-FE), Langat (LGTV), Powassan (POWV), Deer Tick (DTV), Kyasanur Forest Disease (KFDV), Alkhurma hemorrhagic fever (AHFV), and Omsk hemorrhagic fever (OHFV) viruses. DTV, AHFV, and KFDV had the lowest genetic diversity, while POWV strains LEIV-5530 and LB, OHFV, TBEV-Eur, and TBEV-FE had higher genetic diversities. These findings are compatible with the phylogenetic relationships between the viruses. For DTV and POWV, the amount of genetic diversity could be explained by the number of tick vector species and amplification hosts each virus can occupy, with low diversity DTV having a more limited vector and host pool, while POWV with higher genetic diversities has been isolated from different tick species and mammals. It is speculated that high genetic diversity may contribute to the survival of the virus as it encounters these different environments.

Kyasanur forest disease: A review on the emerging infectious disease

Kyasanur forest disease: A review on the emerging infectious disease

Sofosbuvir and its tri-phosphate metabolite inhibit the RNA-dependent RNA polymerase activity of non-structural protein 5 from the Kyasanur forest disease virus

Kyasanur forest disease is a neglected zoonotic disease caused by a single-stranded RNA-based flavivirus, the incidence of which was first recorded in 1957 in the Southern part of India. Kyasanur forest disease virus is transmitted to monkeys and humans through the infected tick bite of Haemophysalis spinigera. Kyasanur forest disease is a febrile illness, which in severe cases, results in neurological complications leading to mortality. The current treatment regimens are symptomatic and supportive, and no targeted therapies are available for this disease. In this study, we evaluated the ability of FDA-approved drugs sofosbuvir (and its active metabolite) and Dasabuvir to inhibit the RNA-dependent RNA polymerase activity of NS5 protein from the Kyasanur forest disease virus. NS5 protein containing the N-terminal methyl transferase domain and C-terminal RNA-dependent RNA polymerase domain was expressed in Escherichia coli, and RNA-dependent RNA polymerase activity was demonstrated with the purified protein. The RNA-dependent RNA polymerase assay conditions were optimized, followed by the determination of apparent Km,ATP to validate the enzyme preparation. Half maximal-inhibitory concentrations against RNA-dependent RNA polymerase activity were determined for Sofosbuvir and its active metabolite. Dasabuvir did not show detectable inhibition with the tested conditions. This is the first demonstration of the inhibition of RNA-dependent RNA polymerase activity of NS5 protein from the Kyasanur forest disease virus with small molecule inhibitors. These initial findings can potentially facilitate the discovery and development of targeted therapies for treating Kyasanur forest disease.

Kyasanur Forest Disease – A Re-emerging Tick-borne Viral Zoonoses

Kyasanur Forest Disease – A Re-emerging Tick-borne Viral Zoonoses

Genomic Determinants Potentially Associated with Clinical Manifestations of Human-Pathogenic Tick-Borne Flaviviruses.

The tick-borne flavivirus group contains at least five species that are pathogenic to humans, three of which induce encephalitis (tick-borne encephalitis virus, louping-ill virus, Powassan virus) and another two species induce hemorrhagic fever (Omsk hemorrhagic fever virus, Kyasanur Forest disease virus). To date, the molecular mechanisms responsible for these strikingly different clinical forms are not completely understood. Using a bioinformatic approach, we performed the analysis of each amino acid (aa) position in the alignment of 323 polyprotein sequences to calculate the fixation index (Fst) per site and find the regions (determinants) where sequences belonging to two designated groups were most different. Our algorithm revealed 36 potential determinants (Fst ranges from 0.91 to 1.0) located in all viral proteins except a capsid protein. In an envelope (E) protein, most of the determinants were located on the virion surface regions (domains II and III) and one (absolutely specific site 457) was located in the transmembrane region. Another 100% specific determinant site (E63D) with Fst = 1.0 was located in the central hydrophilic domain of the NS2b, which mediates NS3 protease activity. The NS5 protein contains the largest number of determinants (14) and two of them are absolutely specific (T226S, E290D) and are located near the RNA binding site 219 (methyltransferase domain) and the extension structure. We assume that even if not absolutely, highly specific sites, together with absolutely specific ones (Fst = 1.0) can play a supporting role in cell and tissue tropism determination.

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

Monkeypox and Monkey Fever: Basic Understanding for Better Community Participation in Disease Control

Currently, Monkeypox is a threatening viral disease terminology around the world that worries the global community after the Coronavirus pandemic. Beyond the woods of central Africa, where cases were first discovered, the geographic distribution of monkeypox cases has extended to other parts of the world including India, where cases have been imported. Under these circumstances, public confusion is noticed between Monkeypox and Monkey fever across southern parts of India. Monkeypox and Monkey fever (Kyasanur Forest Disease) are categorized as potential emerging or re-emerging Zoonotic diseases of humans and are fundamentally having clear-cut differentiation in their causative agent, clinical symptoms, and pathogenesis. Hence, it is important to clarify and eliminate the confusions which would have tremendous and dangerous public health impacts. As defined by the Global Burden of Disease Study, Emerging Infections (EIs) are those that have recently appeared in a population or previously existed but are now gaining in prevalence or geographic spread rapidly. A disease emerges from the interactions between rapidly evolving infectious agents and the environmental changes and changes in human behavior that provide these agents with favorable ecological niches. This review attempts to differentiate between the two emerging infections - Monkeypox and Monkey fever which are affecting a significant group of the population worldwide and provides a comparative picture of both diseases towards developing adequate awareness among the public and expects to complement the community-based future control measures.

Development and application of a recombinant Envelope Domain III protein based indirect human IgM ELISA for Kyasanur forest disease virus

Kyasanur forest virus disease (KFD) is a major public health concern in India. Its etiology KFD virus causes haemorrhagic fever with severe sequelae in humans. Due to continuous spatiotemporal expansion of KFD in last decade, the incidences of positive cases have been increasing in both humans and primates. Early diagnosis is of prime importance for disease management and epidemiological containment. In the present study, the highly immunogenic Envelope Domain III (EDIII) antigen was produced using prokaryotic expression system with an yield of 8 mg/L. The protein was purified using affinity chromatography and confirmed for its immuno-reactivity by western blot and UPLCMS/MS analysis. The recombinant EDIII was used as an antigen for the standardization of ELISA to detect anti KFD IgM antibodies in humans. The ROC curve was prepared to set the optimum cut-off OD for the assay. The comparative evaluation of the assay with a reference MAC ELISA revealed 86.96% concordance, 82.22% sensitivity and 91.48% specificity. Inter-rater agreement was performed with kappa index revealing significant agreement between the assays. This is the first study using safe recombinant protein antigen-based detection of anti KFDV antibodies in humans. This simple and scalable ELISA assay will be applicable for large scale screening of samples for combating the emerging threats of KFD in newer territories.

Mucosal Vaccination: A Promising Alternative Against Flaviviruses.

The Flaviviridae are a family of positive-sense, single-stranded RNA enveloped viruses, and their members belong to a single genus, Flavivirus. Flaviviruses are found in mosquitoes and ticks; they are etiological agents of: dengue fever, Japanese encephalitis, West Nile virus infection, Zika virus infection, tick-borne encephalitis, and yellow fever, among others. Only a few flavivirus vaccines have been licensed for use in humans: yellow fever, dengue fever, Japanese encephalitis, tick-borne encephalitis, and Kyasanur forest disease. However, improvement is necessary in vaccination strategies and in understanding of the immunological mechanisms involved either in the infection or after vaccination. This is especially important in dengue, due to the immunological complexity of its four serotypes, cross-reactive responses, antibody-dependent enhancement, and immunological interference. In this context, mucosal vaccines represent a promising alternative against flaviviruses. Mucosal vaccination has several advantages, as inducing long-term protective immunity in both mucosal and parenteral tissues. It constitutes a friendly route of antigen administration because it is needle-free and allows for a variety of antigen delivery systems. This has promoted the development of several ways to stimulate immunity through the direct administration of antigens (e.g., inactivated virus, attenuated virus, subunits, and DNA), non-replicating vectors (e.g., nanoparticles, liposomes, bacterial ghosts, and defective-replication viral vectors), and replicating vectors (e.g., Salmonella enterica, Lactococcus lactis, Saccharomyces cerevisiae, and viral vectors). Because of these characteristics, mucosal vaccination has been explored for immunoprophylaxis against pathogens that enter the host through mucosae or parenteral areas. It is suitable against flaviviruses because this type of immunization can stimulate the parenteral responses required after bites from flavivirus-infected insects. This review focuses on the advantages of mucosal vaccine candidates against the most relevant flaviviruses in either humans or animals, providing supporting data on the feasibility of this administration route for future clinical trials.

Impact of Plantation Induced Forest Degradation on the Outbreak of Emerging Infectious Diseases-Wayanad District, Kerala, India.

Simple SummaryThe emerging infectious diseases (EIDs) have increased recently due to forest degradation. This research is an attempt to understand the direct and indirect impact of forest degradation on infectious disease outbreaks in a specific context of the Wayanad district in Kerala, India. The study was done in two parts. In the first part, land use and land cover change of the Wayanad district was analyzed for the period of 1950 to 2018. The result of the analysis shows that a significant amount of forest has been converted into agricultural and forest plantations over the time. The second part involves understanding the impact of plantations on the outbreak of EIDs. We have employed GIS tools, remote sensing data, extensive field work and disease data to discover the relationship between the LULCC and disease outbreak. It was found that cases of EIDs were high in those gram panchayats where forests were encroached by plantations.The world has been facing a pandemic owing to COVID-19. We have also seen the geographic expansion and outbreaks of other emerging infectious diseases (EID) in recent years. This paper investigates the direct and indirect effects of land use land cover change (LULCC) on EID outbreaks in the context of Wayanad District of Kerala, India. Wayanad is in the vulnerable tropical forested region, and it is named as one of the four environmental change hotspots. The focus of this project is mainly three EIDs prevalent in this region: Kyasanur forest disease (KFD), Dengue and Leptospirosis. Our results, based on topographical map, remote sensing and extensive field work, show that the natural forest in Wayanad was replaced with agriculture and forest plantation during 1950–2018. This paper further suggests that encroachment of forest by forest plantation causes the human–animal conflict resulting in the outbreak of KFD cases. Our analysis reveals that a high number of Dengue cases is found in the forested regions of the district and over the adjacent human-made agriculture plantation areas. High and medium number of Leptospirosis cases contain a high portion of land area devoted to paddy cultivation and agricultural plantation. In summary, the results clearly show the linkage between the outbreak of above mentioned EIDs and LULCC in the context of Wayanad district, Kerala. We also discuss in detail the causal pathway involving human–environmental dynamics through which plantation leads to the outbreak of KFD. Replacing forests with plantations poses an alarming threat of disease outbreak in the community.

Kinetics of human infection with Kyasanur Forest Disease Virus

Background: Kyasanur Forest disease (KFD) was first reported in 1957 and became an emerging tick-borne viral disease of public health importance in India. However, very little is known about the host-virus interaction and pathogenesis of KFD in humans. This study described the presence, duration, and kinetics of KFDV RNA in body fluids in infected human cases. Methodology: We enrolled 76 laboratory-confirmed KFD individuals and followed them up in the study. We obtained serial samples of blood, throat swabs in viral transport medium (VTM), urine, stool, and semen during the acute and convalescent phase of KFD illness. In addition, specimens were inactivated, and nucleic acid was extracted and tested for KFDV real-time reverse transcriptase -PCR. Clinical data was also obtained from the subjects. Result: The study provides evidence of KFD virus RNA in different biological body fluids of humans. The percentage positivity of KFDV RNA in blood was 100% during the first four days of illness. PCR became negative in most cases by 7–8 days; a subset of cases (14%) had prolonged viremia for up to 15 days post-onset of illness. Relatively low copies of KFDV RNA were also detected in throat swabs and urine in the first week of illness. In addition, we detected KFDV RNA in stool samples of cases of those who had diarrhea at an early stage of infection. Conclusion: The study provides evidence of KFDV RNA in different biological body fluids, which will help understand the pathogenesis, transmission pattern and develop diagnostic algorithms of KFDV in humans. In Kyasanur Forest disease infection, the blood has more RNA copies/ml than other body fluids, and viremia may last up to two weeks post-infection.

Good Medical Entomology Laboratories Practices (GMELP) in India: A Concept Note

Vectors of malaria, filaria, dengue, chikungunya, zika, japanese encephalitis, and kala-azar play an important role in the disease transmission in different eco-settings with variable climatic conditions. Ticks, mites, and fleas also pose a threat to new emerging and re-emerging vector-borne diseases, i.e. Kyasanur Forest Disease (KFD), Crimean Congo Hemorrhagic Fever (CCHF), scrub typhus, and other rickettsioses. Now, the time has come that field oriented entomological work has to shift from open, field based towards closed medical entomological laboratories for undertaking molecular research and pathogen/ virus detection among vector species handling them by minimising human risks. It is imperative to note that there is a strong need for a standard protocol for effective medical entomological laboratory practices while handling the pathogen carrying vector species under laboratory conditions. This may help to prevent the transmission of pathogens/ viruses in case of accidental release of vectors carrying pathogens/ viruses from the entomology laboratories. Such protocols would always help the scientists to minimise risks working in closed conditions. Though, there are guidelines/ procedures available for developing medical entomology laboratory, having facilities for insect rearing, its handling and equipment, however, no specific published protocol or guidelines exist presently in the Indian context. In the present manuscript, the need for a standard protocol for arthropod containment levels (ACLs 1- 4) along with the appropriate bio-safety levels based on the risk potential of pathogen carried by the vector species has been discussed for its application at the ground by the respective health authorities/ institutions.The presence of Standard Operating Procedures (SoPs) and guidelines on Good Medical Entomology Laboratory Practices (GMELP) would help the professionals working in a medical entomology laboratory to minimise risks. There is a need to develop and follow Good Medical Entomology Laboratory Practices (GMELP) for handling the vectors (Arthropods) carrying the pathogens/ viruses at the national/ state/ district level as well as by the research institutes, medical colleges, and universities. The present concept note shall help to provide a guiding principle to develop standard operating procedure (SoP)/ Guidelines for GMELP.

Neurological manifestations of Kyasanur Forest disease: a retrospective cohort study from South India.

Kyasanur Forest disease (KFD) is a viral zoonotic disease where patients present with febrile illness and haemorrhagic manifestations in the first phase. In a small fraction of patients, the fever may be biphasic. This study aimed to describe the neurological manifestations of patients with KFD in the first and second phases of the illness. This is a retrospective cohort study of 297 patients admitted with a molecular diagnosis of KFD from December 2018 to December 2020. The case records of these patients were reviewed for evidence of neurological involvement. A total of 34 (11.5%) patients in the first phase and 16 (36.4%) patients in the second phase had neurological involvement. Altered sensorium, seizures and focal infarcts were common in the first phase, while cerebellar signs and leptomeningeal enhancement were common in the second phase. Neurological involvement is seen in both phases of KFD. While in the first phase it is a result of possible encephalitis/encephalopathy, the second phase involvement is possibly due to postinfectious cerebellitis or meningitis.

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.

Kyasanur forest disease and climatic attributes in India.

In India, Kyasanur Forest Disease has been reported from the states of Karnataka, Kerala, Goa, and Maharashtra. The relationship between climatic factors and transmission of KFD remains untouched, therefore, the present study was undertaken. Based on the occurrence of cases, Shivamogga district (Karnataka) and Wayanad district in Kerala and northern Goa (Goa state) were selected for the study. Data on the incidence of KFD and climate factors were collected from concerned authorities. To determine the relationship between dependent and independent variables, spearman's correlation was calculated for monthly as well as with lag months. KFD cases and temperature (°C) were found significantly correlated up to 1 months' lag period (p<0.05) while with precipitation relationship was found negatively significant for 0-3 months' lag. The range of suitable temperature for KFD in Shivamogga, Goa and Wayanad was found as 20-31°C, 25-29°C and 27-31°C respectively. The cumulative precipitation during transmission months (November-May) ranged from <150-500mm, while in non-transmission months (June-October) from >1100-2400mm. The analysis of three sites revealed that with the increase in temperature, the intensity of KFD transmission decreases as corroborated by the seasonal fluctuations in Shivamogga, Goa and Wayanad. High precipitation from June to October rovides suitable ecology to tick vector and sets in transmission season from November to May when cumulative precipitation is <500 mm.

Effectiveness of One Health approach for control of Kyasanur Forest Disease in Wayanad, Kerala, India.

Kyasanur Forest Disease (KFD) is a vector borne haemorrhagic fever that is endemic in the Wayanad region located in Northern part of Kerala, India. The region is managing the outbreak well ever since the major epidemic of 2015. This was because of the successful implementation of One Health (OH) initiative concentrating on multisectoral collaboration between regional institutions involved in public, animal and environmental health domains. The article presents how OH was implemented for the first time in the district in the year 2015 and evaluates the degree OH-ness of the Initiative. The OH approach involved trans-disciplinary stakeholder meetings and reviews, outbreak management and integrated surveillance targeting ticks, monkeys and humans. The degree of OH-ness used for addressing KFD during the year 2015 was evaluated following the protocol developed by the Network for Evaluation of One Health (NEOH). In detail, we (i) described the OH initiative and its system (Aim, stakeholders, action strategy) and (ii) scored different aspects of this initiative (i.e., OH-thinking, -planning, -working, -sharing, -learning, -organization), with values from 0 (=no OH approach) to 1 (=perfect OH approach). We obtained a median score for each aspect evaluated. We reached high scores for OH systemic organization (1.0), OH thinking (0.83) and OH working (0.83). Lower scores were attributed to OH planning (0.58), OH sharing (0.50) and OH learning (0.33). The OH index was 0.36 and OH ratio was 0.95, indicating a balance between the OH operations and supporting infrastructures. With this we could high-light some critical issues related to communication on sharing data as well as learning gaps for consideration to control future outbreaks. The strengths and weaknesses detected may be used to refine the initiative, aiming to provide a basis for the development of shared recommendations in a more OH-oriented perspective. This model of evaluation criteria will serve to create a database of OH success stories in India that will in turn help to institutionalize the approach at ministerial level. Future India is moving towards implementing a One Health, hence, this study data will provide an ideal opportunity for all sectors to control any vector borne diseases.

Development of Nipah virus-specific IgM & IgG ELISA for screening human serum samples.

Nipah virus (NiV) is a zoonotic paramyxovirus that causes fatal encephalitis in humans. Enzyme Linked Immunosorbent Assay (ELISA) is a safe, sensitive, specific, and affordable diagnostic tool that can be used during screening of large-scale epidemiological investigations. Development and evaluation of IgM and IgG ELISA for screening serum samples of NiV suspected cases would also help in planning public health interventions. An IgM capture (MAC) ELISA and an indirect IgG ELISA were developed using NiV antigen to detect IgM and IgG antibodies against NiV in human sera. The sensitivity, specificity, and cross-reactivity of the assays were evaluated using NiV IgM, IgG positive, negative human sera and measles, mumps, rubella, Crimean-Congo haemorrhagic fever, Kyasanur forest disease IgM, IgG positive sera, respectively. The developed anti-NiV IgM and IgG ELISAs have shown specificity of 99.28 per cent and sensitivity of 100 per cent compared to reference test from Centers for Disease Control and Prevention, USA. Assays demonstrated negative predictive value of 100 per cent and positive predictive value as 90 and 93.94 per cent for anti-Nipah IgM ELISA and IgG ELISA respectively with test accuracy of 99.33 per cent. Timely diagnosis of NiV is crucial for the management of cases, which could prevent further spread of infection in the community. IgM ELISA can be used as primary diagnostic tool followed by polymerase chain reaction. These assays have advantages of its applicability during outbreak investigations and surveillance activities at hospital or onsite laboratories with basic biosafety practices.

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

BackgroundKyasanur 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.AimThe 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 methodsThis 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.ResultsSixty 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%.ConclusionsThe 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.