Recent advances in combating Nipah virus

The Current Pathogenicity and Potential Risk Assessment of Nipah Virus as Potential Cause of "Disease X": A Narrative Review

Background and Aims

The World Health Organization (WHO) recognized the potential for a severe international epidemic and introduced the term "Disease X" to classify pathogens that not yet identified. The Nipah virus (NiV) is highly dangerous due to its zoonotic nature, high mortality rate, and ability to cause severe clinical symptoms in humans. In this review, we gather the latest information on the NiV and its potential to become a significant candidate for Disease X.

Methods

We performed a thorough review of articles published in PubMed, Scopus, and Google Scholar using appropriate MeSH terms and keywords. Studies reported NiV infection were considered for this review.

Results

The NiV exhibits different epidemiological patterns in different countries that calls for customized prevention and control strategies. Genetic analysis highlights NiV's ability to mutate that alters possible treatment options. Transmission typically involves bats as the primary reservoir, with humans becoming infected either through intermediate hosts or food. This shows NiV's complex nature, including its ability to reach the central nervous system through the olfactory nerve. Promising treatment options, such as monoclonal antibodies, antivirals, and ongoing vaccine research, provide hope. However, the virus's adaptability, human-to-human transmission, and the lack of specific antiviral therapy raise concerns about its potential to cause a global pandemic. The interconnection between animals, humans, and the environment stresses the need for a One Health approach to tackle emerging infectious disease by NiV.

Conclusion

Global collaboration, surveillance, and research investments are imperative for the preparation of future pandemics. The ongoing COVID-19 challenges underscoring the critical need for sustained scientific endeavors, global leadership, and recognition of the prominence of NiV as a candidate for the potential Disease X.

Risk Evaluation and Mitigation Strategies for Potential Outbreaks of Nipah Virus Infection: Evidenced by the Recent Incidences in Southeast Asian Countries

Background

The importance of studying Nipah virus (NiV) stems from its high fatality rates and potential for causing widespread outbreaks. Recent incidences in Southeast Asian countries highlight the urgent need for effective risk evaluation and mitigation strategies.

Justification

Studying NiV in Southeast Asia is crucial due to the geographic and epidemiological significance that makes this region predominantly susceptible to the virus.

Objectives

This study aims to identify the risk factors of NiV, evaluate current mitigation strategies, and suggest improvements against this virus.

Methods

This review incorporates articles from the PubMed database related to available NiV treatments, vaccines, mitigation strategies, transmission data, and mortality to comprise an extensive analysis of pertinent information.

Findings

NiV warrants international attention, due to the high mortality rate and the rising number of human-to-human transmission vectors. NiV is difficult to diagnose early on in the infection due to its generic symptoms, and the two strains of NiV (B and M), pose significant challenges to healthcare institutions. Vaccines, such as the VSV-stored, virus-like particle-based, and mRNA-based NiV show promising results in both animal and human studies. Synthetic medicines, like Ribavirin, and favipiravir showed promising results in NiV-infected patients. Therapeutic infectious particles increased survival from 10% to roughly 70%-80% in animals. Phytochemicals, like serpentine and neoandrographolide are alternatives to NiV-G ligands. Griffithsin, an algae derivative has also shown efficacy in treating NiV infections. Artificial intelligence determines the NiV infection with an accuracy of 88.3%.

Conclusions

The strategies to control NiV must be one of a One Health approach, incorporating environmental and social factors. Extensive research on vaccines that showed promising results in animals needs to be tested for humans on a large scale. The major mitigation strategy available is the public awareness during the outbreak about NiV transmission vectors, quarantine protocol, and food hygiene.

Recent Advances in Immunological Landscape and Immunotherapeutic Agent of Nipah Virus Infection

Over the last two decades, the Nipah virus (NiV) emerged as a highly lethal zoonotic pathogen to humans. Outbreaks occurred occasionally in South and Southeast Asia. Therefore, a safe and effective vaccine against the virus is needed to fight against the deadly virus. Understanding the immunological landscape during this lethal virus infection is necessary in this direction. However, we found scattered information on the immunological landscape of the virus's reservoir, as well as hosts such as humans and livestock. The review provides a recent understanding of the immunological landscape of the virus's reservoir, human hosts, monoclonal antibodies, and vaccines for NiV infection. To describe the immunological landscape, we divided our review article into some points. Firstly, we illustrated bats' immune response as a reservoir during the NiV infection. Secondly, we illustrated an overview of the molecular mechanisms underlying the immune response to the NiV infection, various immune cells, humans' innate immune response, adaptive immunity, and the landscape of cytokines and chemokines. We also discussed INF escape, NET evasion, the T cell landscape, and the B cell landscape during virus infection. Thirdly, we also demonstrated the potential monoclonal antibody therapeutics, and vaccines. Finally, neutralizing antibodies (nAbs) of NiV and potentially other therapeutic strategies were discussed. The review will help researchers for better understanding the immunological landscape, mAbs, and vaccines, enabling them to develop their next-generation versions.

A systematic review of case reports on mortality, modes of infection, diagnostic tests, and treatments for Nipah virus infection

BACKGROUND

First identified in Malaysia in 1998, the Nipah virus is a paramyxovirus related to the Hendra virus. The clinical manifestation can vary from a silent infection to a life-threatening encephalitis. The World Health Organization (WHO) has documented 25 outbreaks in South Asia, resulting in 429 cases and 307 deaths to date. Currently, there are no approved treatments for the deadly Nipah virus infection, which is a serious threat to public health worldwide. Consequently, a review was conducted to examine the geographic distribution of the Nipah virus, mortality, transmission pathways, and available methods for diagnosis and treatment.

METHODS

PubMed, Scopus, Web of Science, and Google Scholar servers were used to conduct a systematic search in compliance with the PRISMA guidelines. The results were tabulated and analyzed.

RESULTS

A total of 12 studies (7 case series and 5 case reports) were included in the final analysis, and 92 cases were analyzed. The most frequent symptoms were fever (80%), myalgia (47%), headache (47%), shortness of breath/acute respiratory distress syndrome (n = 44.1%), altered sensorium (44.1%), and vomiting (42.6%). The most commonly used diagnostic test was RT-PCR (45.5%). The most common route of transmission reported is direct human contact with the infected patients. Treatment modalities include interventional procedures, antiviral drugs, and symptomatic treatment. The most common complications were seizures (39.2%) and altered sensorium (35.7%). The mortality rate was 73.9%.

CONCLUSION

It is crucial to emphasize the importance of early Nipah virus infection diagnosis and treatment to prevent life-threatening consequences.

High-throughput virtual screening of Streptomyces spp. metabolites as antiviral inhibitors against the Nipah virus matrix protein

Nipah virus (NiV) remains a significant global concern due to its impact on both the agricultural industry and human health, resulting in substantial economic and health consequences. Currently, there is no cure or commercially available vaccine for the virus. Therefore, it is crucial to prioritize the discovery of new and effective treatment options to prevent its continued spread. Streptomyces spp. are rich sources of metabolites known for their bioactivity against certain diseases; however, their potential as antiviral drugs against the Nipah virus remain unexplored. In this study, 6524 Streptomyces spp. metabolites were screened through in silico methods for their inhibitory effects against the Nipah virus matrix (NiV-M) protein, which assists in virion assembly of Nipah virus. Different computer-aided tools were utilized to carry out the virtual screening process: ADMET profiling revealed 913 compounds with excellent safety and efficacy profiles, molecular docking predicted the binding poses and associated docking scores of the ligands in their respective targets, MD simulations confirmed the binding stability of the top ten highest-scoring ligands in a 100 ns all-atom simulation, PCA elucidated simulation convergence, and MMPB(GB)SA calculations estimated the binding energies of the final candidate compounds and determined the key residues crucial for complex formation. Using in silico methods, we identified six metabolites targeting the main substrate-binding site and five targeting the dimerization site that exhibited excellent stability and strong binding affinity. We recommend testing these compounds in the next stages of drug development to confirm their effectiveness as therapeutic agents against Nipah virus.

A top-down approach for studying the in-silico effect of the novel phytocompound tribulusamide B on the inhibition of Nipah virus transmission through targeting fusion glycoprotein and matrix protein

The proteins of Nipah virus ascribe to its lifecycle and are crucial to infections caused by the virus. In the absence of approved therapeutics, these proteins can be considered as drug targets. This study examined the potential of fifty-three (53) natural compounds to inhibit Nipah virus fusion glycoprotein (NiV F) and matrix protein (NiV M) in silico. The molecular docking experiment, supported by the principal component analysis (PCA), showed that out of all the phytochemicals considered, Tribulusamide B had the highest inhibitory potential against the target proteins NiV F and NiV M (-9.21 and -8.66 kcal mol-1, respectively), when compared to the control drug, Ribavirin (-7.01 and -6.52 kcal mol-1, respectively). Furthermore, it was found that Tribulusamide B pharmacophores, namely, hydrogen donors, acceptors, aromatic and hydrophobic groups, contributed towards the effective residual interactions with the target proteins. The molecular dynamic simulation further validated the results of the docking studies and concluded that Tribulusamide B formed a stable complex with the target proteins. The data obtained from MM-PBSA study further explained that the phytochemical could strongly bind with NiV F (-31.26 kJ mol-1) and NiV M (-40.26 kJ mol-1) proteins in comparison with the control drug Ribavirin (-13.12 and -13.94 kJ mol-1, respectively). Finally, the results indicated that Tribulusamide B, a common inhibitor effective against multiple proteins, can be considered a potential therapeutic entity in treating the Nipah virus infection.

Recuperative potential of Indian medicinal plant compounds- a tool to encumber henipaviruses: an in -silico study

Henipaviruses, highly fatal zoonotic viruses with mortality rates up to 100%, pose a significant threat to humans. Despite sporadic cases, including infections from Cedar, Langya, and Nipah Viruses, there are no established drugs or vaccines for treatment. This lack of specific medication led us to explore 57 non-toxic compounds from Indian Medicinal Plants, selected from 232 compounds, aiming to combat these viruses. Through in silico ADMET analyses, Three compounds-andrographolide, pterygospermin and Salidroside-stood out for their exceptional non-toxic properties. These compounds underwent in silico target prediction, molecular docking and dynamics with Cedar, Langya, and Nipah Virus proteins from the Protein Data Bank. Among them, Andrographolide displayed the most promising negative free energy scores and stability in Cedar Virus-Attachment G-Protein binding pockets. Pterygospermin and Salidroside showed efficacy against Langya and Nipah Virus target proteins throughout the simulation. These compounds not only exhibited antiviral properties but also demonstrated immunomodulatory, anti-inflammatory, and hepatoprotective effects by our in-silico studies. Their potential as treatments or preventive measures against henipaviral infections makes them promising candidates for further research and development.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-024-00236-x.

Revolutionizing Nipah virus vaccinology: insights into subunit vaccine development strategies and immunological advances

The Nipah virus (NiV), a zoonotic virus in the Henipavirus genus of the Paramyxoviridae family, emerged in Malaysia in 1998 and later spread globally. Diseased patients may have a 40- 70% chance of fatality depending on the severity and early medication. The recent outbreak of NiV was reported in Kerala (India) by a new strain of MCL-19-H-1134 isolate. Currently, no vaccines are available, highlighting the critical need for a conclusive remedy. Our study aims to develop a subunit vaccine against the NiV by analyzing its proteome. NiV genome and proteome sequences were obtained from the NCBI database. A phylogenetic tree was constructed based on genome alignment. T-cell, helper T-cell, and B-cell epitopes were predicted from the protein sequences using NetCTL-1.2, NetMHCIIPan-4.1, and IEDB servers, respectively. High-affinity epitopes for human receptors were selected to construct a multi-epitope vaccine (MEV). These epitopes' antigenicity, toxicity, and allergenicity were evaluated using VaxiJen, AllergenFP-v.1.0, and AllergenFP algorithms. Molecular interactions with specific receptors were analyzed using PyRx and ClusPro. Amino acid interactions were visualized and analyzed using PyMOL and LigPlot. Immuno-simulation was conducted using C-ImmSim to assess the immune response elicited by the MEV. Finally, the vaccine cDNA was inserted into the pET28a(+) expression vector using SnapGene tool for in silico cloning in an E. coli host. The potential for an imminent outbreak cannot be overlooked. A subunit vaccine is more cost-effective and time-efficient. With additional in vitro and in vivo validation, this vaccine could become a superior preventive measure against NiV disease.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-024-00246-9.

A potent Henipavirus cross-neutralizing antibody reveals a dynamic fusion-triggering pattern of the G-tetramer

The Hendra and Nipah viruses (HNVs) are highly pathogenic pathogens without approved interventions for human use. In addition, the interaction pattern between the attachment (G) and fusion (F) glycoproteins required for virus entry remains unclear. Here, we isolate a panel of Macaca-derived G-specific antibodies that cross-neutralize HNVs via multiple mechanisms. The most potent antibody, 1E5, confers adequate protection against the Nipah virus challenge in female hamsters. Crystallography demonstrates that 1E5 has a highly similar binding pattern to the receptor. In cryo-electron microscopy studies, the tendency of 1E5 to bind to the upper or lower heads results in two distinct quaternary structures of G. Furthermore, we identify the extended outer loop β1S2-β1S3 of G and two pockets on the apical region of fusion (F) glycoprotein as the essential sites for G-F interactions. This work highlights promising drug candidates against HNVs and contributes deeper insights into the viruses.

Pathogenicity and virulence of henipaviruses

Paramyxoviruses are a family of single-stranded negative-sense RNA viruses, many of which are responsible for a range of respiratory and neurological diseases in humans and animals. Among the most notable are the henipaviruses, which include the deadly Nipah (NiV) and Hendra (HeV) viruses, the causative agents of outbreaks of severe disease and high case fatality rates in humans and animals. NiV and HeV are maintained in fruit bat reservoirs primarily in the family Pteropus and spillover into humans directly or by an intermediate amplifying host such as swine or horses. Recently, non-chiropteran associated Langya (LayV), Gamak (GAKV), and Mojiang (MojV) viruses have been discovered with confirmed or suspected ability to cause disease in humans or animals. These viruses are less genetically related to HeV and NiV yet share many features with their better-known counterparts. Recent advances in surveillance of wild animal reservoir viruses have revealed a high number of henipaviral genome sequences distributed across most continents, and mammalian orders previously unknown to harbour henipaviruses. In this review, we summarize the current knowledge on the range of pathogenesis observed for the henipaviruses as well as their replication cycle, epidemiology, genomics, and host responses. We focus on the most pathogenic viruses, including NiV, HeV, LayV, and GAKV, as well as the experimentally non-pathogenic CedV. We also highlight the emerging threats posed by these and potentially other closely related viruses.

Inactivated Recombinant Rabies Virus Displaying the Nipah Virus Envelope Glycoproteins Induces Systemic Immune Responses in Mice

Nipah virus (NiV) causes severe, lethal encephalitis in humans and pigs. However, there is no licensed vaccine available to prevent NiV infection. In this study, we used the reverse genetic system based on the attenuated rabies virus strain SRV9 to construct two recombinant viruses, rSRV9-NiV-F and rSRV9-NiV-G, which displayed the NiV envelope glycoproteins F and G, respectively. Following three immunizations in BALB/c mice, the inactivated rSRV9-NiV-F and rSRV9-NiV-G alone or in combination, mixed with the adjuvants ISA 201 VG and poly (I:C), were able to induce the antigen-specific cellular and Th1-biased humoral immune responses. The specific antibodies against rSRV9-NiV-F and rSRV9-NiV-G had reactivity with two constructed bacterial-like particles displaying the F and G antigens of NiV. These data demonstrate that rSRV9-NiV-F or rSRV9-NiV-G has the potential to be developed into a promising vaccine candidate against NiV infection.

Emerging Pathogenic Viral Infections of the Eye

Global health security threats and the public health impact resulting from emerging infectious diseases including the ongoing COVID-19 pandemic and recent Ebola virus disease outbreaks continuously emphasize the need for a comprehensive approach to preparedness, management of disease outbreaks, and health sequelae associated with emergent pathogens. A spectrum of associated ophthalmic manifestations, along with the potential persistence of emerging viral pathogens in ocular tissues, highlight the importance of an ophthalmic approach to contributing to efforts in the response to public health emergencies from disease outbreaks. This article summarizes the ophthalmic and systemic findings, epidemiology, and therapeutics for emerging viral pathogens identified by the World Health Organization as high-priority pathogens with epidemic potential.

Nipah virus attachment glycoprotein ectodomain delivered by type 5 adenovirus vector elicits broad immune response against NiV and HeV

Nipah virus (NiV) and Hendra virus (HeV) are newly emerging dangerous zoonotic pathogens of the Henipavirus genus of the Paramyxoviridae family. NiV and HeV (HNVs) which are transmitted by bats cause acute respiratory disease and fatal encephalitis in humans. To date, as there is a lack of antiviral drugs or effective antiviral therapies, the development of vaccines against those two viruses is of primary importance, and the immunogen design is crucial to the success of vaccines. In this study, the full-length protein (G), the ectodomain (Ge) and the head domain (Gs) of NiV attachment glycoprotein were delivered by the replication-defective type 5 adenovirus vector (Ad5) respectively, and the recombinant Ad5-NiV vaccine candidates (Ad5-NiVG, Ad5-NiVGe and Ad5-NiVGs) were constructed and their immunogenicity were evaluated in mice. The results showed that all the vaccine candidates stimulated specific humoral and cellular immune responses efficiently and rapidly against both NiV and HeV, and the Ad5-NiVGe elicited the strongest immune responses after a single-dose immunization. Furthermore, the potent conserved T-cell epitope DTLYFPAVGFL shared by NiV and HeV was identified in the study, which may provide valid information on the mechanism of HNVs-specific cellular immunity. In summary, this study demonstrates that the Ad5-NiVGe could be a potent vaccine candidate against HNVs by inducing robust humoral and cellular immune responses.

Nipah Virus Impairs Autocrine IFN Signaling by Sequestering STAT1 and STAT2 into Inclusion Bodies

Nipah virus (NiV) is an emerging zoonotic paramyxovirus that causes fatal infections in humans. As with most disease-causing viruses, the pathogenic potential of NiV is linked to its ability to block antiviral responses, e.g., by antagonizing IFN signaling through blocking STAT proteins. One of the STAT1/2-binding proteins of NiV is the phosphoprotein (P), but its functional role in IFN antagonism in a full viral context is not well defined. As NiV P is required for genome replication and specifically accumulates in cytosolic inclusion bodies (IBs) of infected cells, we hypothesized that this compartmentalization might play a role in P-mediated IFN antagonism. Supporting this notion, we show here that NiV can inhibit IFN-dependent antiviral signaling via a NiV P-dependent sequestration of STAT1 and STAT2 into viral IBs. Consequently, the phosphorylation/activation and nuclear translocation of STAT proteins in response to IFN is limited, as indicated by the lack of nuclear pSTAT in NiV-infected cells. Blocking autocrine IFN signaling by sequestering STAT proteins in IBs is a not yet described mechanism by which NiV could block antiviral gene expression and provides the first evidence that cytosolic NiV IBs may play a functional role in IFN antagonism.

Mutation of Phenylalanine 23 of Newcastle Disease Virus Matrix Protein Inhibits Virus Release by Disrupting the Interaction between the FPIV L-Domain and Charged Multivesicular Body Protein 4B

The matrix (M) protein FPIV L-domain is conserved among multiple paramyxoviruses; however, its function and the associated mechanism remain unclear. In this study, the paramyxovirus Newcastle disease virus (NDV) was employed to study the FPIV L-domain. Two recombinant NDV strains, each carrying a single amino acid mutation at the Phe (F23) or Pro (P24) site of 23FPIV/I26 L-domain, were rescued. Growth defects were observed in only the recombinant SG10-F23A (rSG10-F23A) strain. Subsequent studies focused on rSG10-F23A revealed that the virulence, pathogenicity, and replication ability of this strain were all weaker than those of wild-type strain rSG10 and that a budding deficiency contributed to those weaknesses. To uncover the molecular mechanism underlying the rSG10-F23A budding deficiency, the bridging proteins between the FPIV L-domain and endosomal sorting complex required for transported (ESCRT) machinery were explored. Among 17 candidate proteins, only the charged multivesicular body protein 4 (CHMP4) paralogues were found to interact more strongly with the NDV wild-type M protein (M-WT) than with the mutated M protein (M-F23A). Overexpression of M-WT, but not of M-F23A, changed the CHMP4 subcellular location to the NDV budding site. Furthermore, a knockdown of CHMP4B, the most abundant CHMP4 protein, inhibited the release of rSG10 but not that of rSG10-F23A. From these findings, we can reasonably infer that the F23A mutation of the FPIV L-domain blocks the interaction between the NDV M protein and CHMP4B and that this contributes to the budding deficiency and consequent growth defects of rSG10-F23A. This work lays the foundation for further study of the FPIV L-domain in NDV and other paramyxoviruses. IMPORTANCE Multiple viruses utilize a conserved motif, termed the L-domain, to act as a cellular adaptor for recruiting host ESCRT machinery to their budding site. Despite the FPIV type L-domain having been identified in some paramyxoviruses 2 decades ago, its function in virus life cycles and its method of recruiting the ESCRT machinery are poorly understood. In this study, a single amino acid mutation at the F23 site of the 23FPIV26 L-domain was found to block NDV budding at the late stage. Furthermore, CHMP4B, a core component of the ESCRT-III complex, was identified as a main factor that links the FPIV L-domain and ESCRT machinery together. These results extend previous understanding of the FPIV L-domain and, therefore, not only provide a new approach for attenuating NDV and other paramyxoviruses but also lay the foundation for further study of the FPIV L-domain.

Syrian Golden Hamster Model for Nipah Virus Infection

Small rodent animal models that recapitulate the symptomology and pathology of the human disease caused by Nipah virus (NiV) are crucial not only to study virus-induced disease but also a critical component for the development of vaccine and therapeutic candidates. The Syrian golden hamster is the most commonly used small animal model for NiV and develops clinical symptoms and pathologies that closely resemble NiV disease in humans. In this chapter, we describe standard techniques used to infect hamsters and conduct evaluation of therapeutics and vaccine candidates.

Nipah virus, an emerging zoonotic disease causing fatal encephalitis

Nipah virus is an acute febrile illness that can cause fatal encephalitis. It is an emerging zoonotic paramyxovirus endemic to south-east Asia and the western Pacific, and can be transmitted by its primary reservoir of fruit bats, through intermediate animal vectors and by human-to-human spread. Outbreaks of Nipah virus encephalitis have occurred in Malaysia, Singapore, Philippines, India and Bangladesh, with the most recent outbreak occurring in Kerala, India in late 2021. Extremely high case fatality rates have been reported from these outbreaks, and to date no vaccines or therapeutic management options are available. Combining this with its propensity to present non-specifically, Nipah virus encephalitis presents a challenging diagnosis that should not be missed in patients returning from endemic regions. Raising awareness of the epidemiology, clinical presentation and risk factors of contracting Nipah virus is vital to recognise and manage potential outbreaks of this disease in the UK.

Nipah amidst Covid-19 Pandemic, another Re-Emerging Infectious Disease of Pandemic Potential - a Narrative Review

Introduction: Nipah virus (NiV) was reported for the first time from the Kampung Sungai Nipah village of Malaysia in 1998. Since then, there have been multiple outbreaks, all of them in South- and South-East Asia. According to the World Health Organization (WHO), up to 75% of Nipah infections were proven to be fatal. Nipah virus belongs to the group of Biosafety Level-4 pathogen associated with high case fatality rate (40-75%). Methodology:According to the PRISMA guidelines for 2020, we searched in four medical databases (PubMed, Google Scholar, EMBASE and Scopus) and selected relevant studies from the past twenty years till November 2021. Review:Nipah virus was first detected in Malaysia's Kampung Sungai Nipah in 1998. By May 1999, the Malaysia Ministry of Health in association with the Centers for Disease Control (CDC) reported a total of 258 cases with a case fatality rate of almost 40%. Nipah in Kozhikode:Experts from the Pune Institute and Bhopal's National Institute of High Security Animal Diseases had collected Bat samples from Pazhoor in Chathamangalam gram panchayat (where a 12-year-old died due to Nipah infection on September 5 carried antibodies of the virus). All Indian outbreaks have seen person-to-person transmission. The virus found in Kerala differed from those two variants in terms of genetic structure. It also differed by 1.96% from the Bangladesh variant. The difference with the Malaysian variant was 8.42%. While PCR is the most sensitive technique for diagnosing active NiV infection, NiV-specific IgM ELISA offers a serological option when PCR is not available. Conclusions:Understanding the fruit bat ecology, NiV illness seasonality, and the transmission risk of various intermediate species requires a One Health approach. The danger of reintroduction into animal or human populations cannot be handled without a thorough understanding of the wildlife reservoir.

Nipah Virus Mystery: Insight into Transmission and Mechanism of Disease Progression

Nipah virus (NiV) belongs to the biosafety level four (BSL-4) group of human pathogens of zoonotic origin. It is an emerging pathogen capable of causing a variety of clinical presentations, including encephalitis and severe acute respiratory illness, which can be fatal. Interestingly, it can also cause asymptomatic infections, which can relapse after a long period of time ranging from months to years following initial infection. Zoonotic transmission involves bats or pigs. In addition, transmission via contaminated food and occasional human to human direct transmission may also occur. It can have diverse epidemiological features and can have a very high case fatality ratio. Although a variety of immunological and molecular assays have been developed and epidemiological monitoring procedures for this disease have been introduced, there are no drugs available for this virus. Vaccines are at different stages of development. In this mini-review, we present the latest information on the Nipah virus; primarily focusing on emergence, transmission, pathogenic mechanisms and possible prophylactic and treatment options.