Human Disease Outbreaks Research Articles

Ultra-low volume (ULV) adulticide treatment impacts age structure of Culex species (Diptera: Culicidae) in a West Nile virus hotspot.

West Nile virus (WNV) invaded the continental United States over 20 years ago and continues to cause yearly seasonal outbreaks of human and veterinary disease. In the suburbs of Chicago, Illinois, ultra-low volume (ULV) truck-mounted adulticide spraying frequently is performed to reduce populations of Culex restuans Theobald and Cx. pipiens L. mosquitoes (Diptera: Culicidae) in an effort to lower the risk of WNV transmission. The effectiveness of this control method has not been rigorously evaluated, and evidence for Culex population reduction after ULV adulticide spraying has been inconclusive. Therefore, we evaluated the results of 5 sequential weekly truck-mounted adulticide applications of Zenivex® E20 (etofenprox) in 2 paired sites located in Cook County, IL, during the summer of 2018. Mosquito population abundance, age structure, and WNV infection prevalence were monitored and compared between paired treatment and nearby control sites. Adulticide treatment did not result in consistent short-term or long-term reductions in target WNV vector Culex abundance. However, there was a significant increase in the proportion of nulliparous females in the treated sites compared to control sites and a decrease in Cx. pipiens WNV infection rates at one of the treated sites. This evidence that ULV adulticide spraying altered the age structure and WNV infection prevalence in a vector population has important implications for WNV transmission risk management. Our findings also underscore the importance of measuring these important indicators in addition to abundance metrics when evaluating the efficacy of control methods.

Review of man to animal transmission of coronavirus disease 2019 (covid-19) infection caused by Severe Acute Respiratory Syndrome Coronavirus 2 (Sars-Cov-2)

Coronaviruses infect a wide variety of animals, including birds and mammals, where they cause infection in animals, mutate and cause disease outbreaks in humans. The review focused on the origin and spread of SARS-CoV-2 from humans to animals. A systematic literature search of PubMed, ProMed-mail, and Google Scholar databases, using keywords "animals", "COVID-19", and "SARS-CoV-2", for articles providing information on animal studies and case reports between December 2019 and September 2021. Published articles included in this review are in English and conducted studies on animals and case reports of human-animal transmission. Fifty-seven COVID-19 in animals published articles featured in this review. Humans can spread the disease to pets (dogs and cats) during close contact when they are clinically infected. Although cats are susceptible to subclinical infection, they developed a robust neutralizing antibody response that prevented re-infection to a second viral challenge in a laboratory setting. Clinically positive Farm workers on mink farms tend to spread the disease to the Minks. Pangolins are a natural reservoir of SARS-CoV-2-like CoVs, the Coronaviruses most related to SARSCoV-2. Companion animals living with infected owners are at risk of Man-to-animal spread of the SARS-CoV-2 virus. Therefore, applying basic hygiene measures such as handwashing when handling and caring for animals is suggested.

Preexisting Immunity Does Not Prevent Efficacy of Vesicular Stomatitis Virus-Based Filovirus Vaccines in Nonhuman Primates.

Ebola virus (EBOV) and Marburg virus (MARV) made headlines in the past decade, causing outbreaks of human disease in previously nonendemic yet overlapping areas. While EBOV outbreaks can be mitigated with licensed vaccines and treatments, there is not yet a licensed countermeasure for MARV. Here, we used nonhuman primates (NHPs) previously vaccinated with vesicular stomatitis virus (VSV)-MARV and protected against lethal MARV challenge. After a resting period of 9 months, these NHPs were revaccinated with VSV-EBOV and challenged with EBOV, resulting in 75% survival. Surviving NHPs developed EBOV glycoprotein (GP)-specific antibody titers and no viremia or clinical signs of disease. The single vaccinated NHP succumbing to challenge showed the lowest EBOV GP-specific antibody response after challenge, supporting previous findings with VSV-EBOV that antigen-specific antibodies are critical in mediating protection. This study again demonstrates that VSVΔG-based filovirus vaccine can be successfully used in individuals with preexisting VSV vector immunity, highlighting the platform's applicability for consecutive outbreak response.

A One Health approach to mitigate the impact of influenza A virus (IAV) reverse zoonosis is by vaccinating humans and susceptible farmed and pet animals.

The term reverse zoonosis specifically refers to the natural transmission of disease and infection from humans to animals, with humans as the reservoir host replicating the infectious agent. In the last 20 years, reverse zoonosis has increasingly garnered attention because of human disease outbreaks. In this Currents in One Health article, the author will review host range as the main risk factor for reverse zoonosis, with an emphasis on influenza A virus (IAV) disease events in humans and other species in the context of a "One Health" approach to gain a better understanding of their transmission routes to facilitate their control and prevent them from occurring. The human-to-pig transmission of IAV represents the largest reverse zoonosis of a pathogen documented to date. At the same time, the 2022 farmed mink outbreak in Spain is the most sustained mammal-to-mammal transmission of the highly pathogenic avian influenza (HPAI) H5N1 since its re-emergence in humans in 2003. Without any prospect of eradicating IAVs, the best way to mitigate the impact of IAV reverse zoonosis is by vaccinating humans and susceptible farmed and pet animals. The recent major reverse zoonoses involving other virus groups (Coronaviridae, Poxviridae, arboviruses, and the human respiratory viruses transmitted to endangered non-human primate species) and the prevention and control of reverse zoonoses are addressed in the companion Currents in One Health by Kibenge, JAVMA, June 2023.

Clinical Characteristics of the 2019 Eastern Equine Encephalitis Outbreak in Michigan.

Eastern equine encephalitis virus is a mosquito-borne alphavirus responsible for unpredictable outbreaks of severe neurologic disease in animals and humans. While most human infections are asymptomatic or clinically nonspecific, a minority of patients develops encephalitic disease, a devastating illness with a mortality rate of ≥30%. No treatments are known to be effective. Eastern equine encephalitis virus infection is rare in the United States, with an annual average nationwide incidence of 7 cases between 2009 and 2018. However, in 2019, 38 cases were confirmed nationwide, including 10 in Michigan. Data from 8 cases identified by a regional network of physicians in southwest Michigan were abstracted from clinical records. Clinical imaging and histopathology were aggregated and reviewed. Patients were predominantly older adults (median age, 64 years), and all were male. Results of initial arboviral cerebrospinal fluid serology were frequently negative, and diagnosis was not made until a median of 24.5 days (range, 13-38 days) after presentation, despite prompt lumbar punctures in all patients. Imaging findings were dynamic and heterogeneous, with abnormalities of the thalamus and/or basal ganglia, and prominent pons and midbrain abnormalities were displayed in 1 patient. Six patients died, 1 survived the acute illness with severe neurologic sequelae, and 1 recovered with mild sequelae. A limited postmortem examination revealed diffuse meningoencephalitis, neuronophagia, and focal vascular necrosis. Eastern equine encephalitis is a frequently fatal condition whose diagnosis is often delayed, and for which no effective treatments are known. Improved diagnostics are needed to facilitate patient care and encourage the development of treatments.

Zoonotic risk assessment among farmed mammals

Farmed mammals may act as hosts for zoonotic viruses that can cause disease outbreaks in humans. This SnapShot shows which farmed mammals, and to what extent, are of particular risk of harboring and spreading viruses from viral families that are commonly associated with zoonotic disease. It also discusses genome surveillance methods and biosafety measures. To view this SnapShot, open or download the PDF.

Human disturbance increases coronavirus prevalence in bats

Human land modification is a known driver of animal-to-human transmission of infectious agents (zoonotic spillover). Infection prevalence in the reservoir is a key predictor of spillover, but landscape-level associations between the intensity of land modification and infection rates in wildlife remain largely untested. Bat-borne coronaviruses have caused three major disease outbreaks in humans: severe acute respiratory syndrome (SARS), Middle East respiratory syndrome, and coronavirus disease 2019 (COVID-19). We statistically link high-resolution land modification data with bat coronavirus surveillance records and show that coronavirus prevalence significantly increases with the intensity of human impact across all climates and levels of background biodiversity. The most significant contributors to the overall human impact are agriculture, deforestation, and mining. Regions of high predicted bat coronavirus prevalence coincide with global disease hotspots, suggesting that infection prevalence in wildlife may be an important factor underlying links between human land modification and zoonotic disease emergence.

Deciphering the complete human-monkeypox virus interactome: Identifying immune responses and potential drug targets.

Monkeypox virus (MPXV) is a dsDNA virus, belonging to Poxviridae family. The outbreak of monkeypox disease in humans is critical in European and Western countries, owing to its origin in African regions. The highest number of cases of the disease were found in the United States, followed by Spain and Brazil. Understanding the complete infection mechanism of diverse MPXV strains and their interaction with humans is important for therapeutic drug development, and to avoid any future epidemics. Using computational systems biology, we deciphered the genome-wide protein-protein interactions (PPIs) between 22 MPXV strains and human proteome. Based on phylogenomics and disease severity, 3 different strains of MPXV: Zaire-96-I-16, MPXV-UK_P2, and MPXV_USA_2022_MA001 were selected for comparative functional analysis of the proteins involved in the interactions. On an average, we predicted around 92,880 non-redundant PPIs between human and MPXV proteomes, involving 8014 host and 116 pathogen proteins from the 3 strains. The gene ontology (GO) enrichment analysis revealed 10,624 common GO terms in which the host proteins of 3 strains were highly enriched. These include significant GO terms such as platelet activation (GO:0030168), GABA-A receptor complex (GO:1902711), and metalloendopeptidase activity (GO:0004222). The host proteins were also significantly enriched in calcium signaling pathway (hsa04020), MAPK signaling pathway (hsa04010), and inflammatory mediator regulation of TRP channels (hsa04750). These significantly enriched GO terms and KEGG pathways are known to be implicated in immunomodulatory and therapeutic role in humans during viral infection. The protein hubs analysis revealed that most of the MPXV proteins form hubs with the protein kinases and AGC kinase C-terminal domains. Furthermore, subcellular localization revealed that most of the human proteins were localized in cytoplasm (29.22%) and nucleus (26.79%). A few drugs including Fostamatinib, Tamoxifen and others were identified as potential drug candidates against the monkeypox virus disease. This study reports the genome-scale PPIs elucidation in human-monkeypox virus pathosystem, thus facilitating the research community with functional insights into the monkeypox disease infection mechanism and augment the drug development.

Characterisation of new animal cell cultures’ sensitivity to <i>Coxsackievirus B5</i> and <i>Herpes simplex virus‑1</i>

The increase in the number of cell cultures for virology and biotechnology enhances the chances of a successful response to threats related to outbreaks of well-known and new human infectious diseases. It is a vital task to search for cell cultures sensitive to a wide spectrum of viruses.The aim of the study was to investigate the sensitivity of new diploid animal cell cultures (fibroblasts of a foetal pig’s kidneys and larynx) to Coxsackievirus B5 (CVB5) and Herpes simplex virus-1 (HSV-1).Materials and methods. The cultures of porcine foetal kidney fibroblasts (PFKF) and porcine foetal larynx fibroblasts (PFLF) were derived from a foetus of a healthy pig by mild trypsinisation. The study determined the sensitivity of these new PFKF and PFLF cultures to the above-mentioned viruses by the cytopathic effect (CPE) expressed as a percentage. The infectious activity of CVB5 was studied using real-time polymerase chain reaction (PCR) with the determination of amplification cycle threshold values (Ct); that of HSV-1 was studied using quantitative titration of the virus-containing liquid (VCL). Infectious activity values were expressed as tissue culture 50% infective doses (TCID50).Results. The authors developed diploid PFKF and PFLF cell cultures. PFKF cells demonstrated high sensitivity to CVB5, with a CPE of 87.5±3.3% after passage 3 and a satisfactory concentration of enterovirus RNA in the VCL of 22–24 Ct . The sensitivity of PFKF cells to HSV-1 corresponded to a CPE of 92.1±5.5%. In these cells, the infectious activity of HSV-1 corresponded to 104.25 TCID50/0.2 mL. The experiments with PFLF cells showed low CPE and infectious activity values for both viruses.Conclusions. The study demonstrated high CPE values with the CVB5 (CB5-8100) and HSV-1 (HSV-1/L-2) strains as examples and confirmed the sensitivity of the new diploid PFKF cell culture to these test viruses. Thus, the PFKF cell culture offers potential applications in virology and biotechnology and may be a candidate for testing other strains of CVB5 and HSV-1.

Expression profiles of lncRNAs and their possible regulatory role in monocrotaline-induced HSOS in rats.

Aims: Long non-coding RNAs (lncRNAs) contribute to the regulation of vital physiological processes and play a role in the pathogenesis of many diseases. Monocrotaline (MCT) can cause large-scale outbreaks of toxic liver disease in humans and animals in the form of hepatic sinusoidal obstruction syndrome (HSOS). Although many experiments have been carried out to explain the pathogenesis of Monocrotaline-induced hepatic sinusoidal obstruction syndrome and to develop treatments for it, no studies have examined the role of Long non-coding RNAs in this condition. This study aimed to investigate the Long non-coding RNAs-mRNA regulation network in Monocrotaline-induced hepatic sinusoidal obstruction syndrome in rats. Main methods: We established a model for MCT-induced hepatic sinusoidal obstruction syndrome, and then carried out microarray for liver tissues of SD rats in a model of early hepatic sinusoidal obstruction syndrome (12h Monocrotaline treatment vs. control group) to investigate the differentially expressed Long non-coding RNAs and mRNAs in early hepatotoxicity. This was followed by RT-PCR analysis of selected Long non-coding RNAs, which were markedly altered. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genome analyses were also conducted. Key findings: 176 Long non-coding RNAs (63 downregulated and 113 upregulated) and 4,221 mRNAs (2,385 downregulated and 1836 upregulated) were differentially expressed in the Monocrotaline-treated group compared to the control group. The biological processes identified in GO enrichment analysis as playing a role in hepatotoxicity were positive regulation of guanosine triphosphate phosphohydrolase, liver development, and the oxidation-reduction process. Pathway analysis revealed that the metabolism pathways, gap junction, and ribosome biogenesis in eukaryotes were closely related to Monocrotaline-induced hepatotoxicity. According to these analyses, LOC102552718 might play an essential role in hepatotoxicity mechanisms by regulating the expression of inositol 1,4,5-trisphosphate receptor-1 (Itpr-1). Significance: This study provides a basis for further research on the molecular mechanisms underlying Monocrotaline-induced hepatotoxicity and its treatment, especially in the early stage, when successful treatment is critical before irreversible liver damage occurs.

A compartmental model for the spread of Nipah virus in a periodic environment

<abstract><p>Nipah virus (NiV) is a zoonotic virus that causes outbreaks of fatal disease in humans. Fruit bat, also known as the flying fox, is the animal host reservoir for NiV. It is known to cause illness in pigs, which are considered an intermediate host. In this paper, we propose a model for NiV disease transmission taking into account all human-to-host animal transmission as well as the loss of immunity in those who have recovered. Furthermore, we take into consideration seasonal effects such as varying transmission rate from bats and birth rate of bats. We studied the existence and uniqueness of a disease-free $ \omega $-periodic solution and later deals with the basic reproduction number and stability analysis. To support the analytical results we provide numerical examples and assess the effect of parameter changes on disease dynamics, which might help to understand how to avoid a yearly periodic recurrence of the disease.</p></abstract>

Ferret Models for Henipavirus Infection.

Henipaviruses are emerging zoonotic viruses that can cause outbreaks of severe respiratory and neurological disease in humans and animals such as horses. The mechanism by which these viruses can cause disease remain largely unknown and to date there are no therapeutics or vaccines approved for use in humans. Nipah virus is listed on the World Health Organization R & D Blueprint list of epidemic threats. In order to advance the availability of effective therapeutics and vaccines and medicines that can be used to save lives and avert large scale crises, animal models are required which recapitulate the disease progression in humans. Ferrets are highly susceptible to infection with henipaviruses and develop both severe respiratory and neurological disease. Therefore, the ferret model is highly suitable for studies into both the pathogenesis of henipaviruses, as well as pre-clinical evaluation of intervention strategies.

A One Health look into the emergence of zoonotic viruses at the human-animal-environment interface

Abstract Emerging zoonotic viruses are a major public health concern, and they have caused the majority of human infectious disease outbreaks in recent decades. It is known that the emergence of zoonotic diseases is facilitated by human-caused environmental changes such as deforestation and changes in global climatic conditions. However, the complex interactions between these environmental elements and the contribution of each factor to the emergence and spread of zoonotic viral pathogens are not sufficiently addressed. Therefore, this article presents an overview of the available scientific knowledge on the major anthropogenic and climatic drivers of emerging zoonotic viruses, and also discusses the interconnections among human health, animal health, and ecosystem health in the context of emerging zoonotic viruses, and how the One Health approach can be implemented in reducing the health risks of emerging zoonotic viral pathogens. One Health impact statement The One Health approach has got more attention post-COVID-19 pandemic. However, there are multiple challenges in its real-world application. This paper presents a general One Health application framework that describes how a national One Health risk analysis (OHRA) system can be designed and implemented to predict, prevent, and control emerging zoonotic viral pathogens at the human-animal-environment interface.

Comparing Short-Term Univariate and Multivariate Time-Series Forecasting Models in Infectious Disease Outbreak.

Predicting infectious disease outbreak impacts on population, healthcare resources and economics and has received a special academic focus during coronavirus (COVID-19) pandemic. Focus on human disease outbreak prediction techniques in current literature, Marques et al. (Predictive models for decision support in the COVID-19 crisis. Springer, Switzerland, 2021) state that there are four main methods to address forecasting problem: compartmental models, classic statistical models, space-state models and machine learning models. We adopt their framework to compare our research with previous works. Besides being divided by methods, forecasting problems can also be divided by the number of variables that are considered to make predictions. Considering this number of variables, forecasting problems can be classified as univariate, causal and multivariate models. Multivariate approaches have been applied in less than 10% of research found. This research is the first attempt to evaluate, over real time-series data of 3 different countries with univariate and multivariate methods to provide a short-term prediction. In literature we found no research with that scope and aim. A comparison of univariate and multivariate methods has been conducted and we concluded that besides the strong potential of multivariate methods, in our research univariate models presented best results in almost all regions' predictions.

Monkeypox Virus Infections in Humans.

Human monkeypox is a viral zoonosis endemic to West and Central Africa that has recently generated increased interest and concern on a global scale as an emerging infectious disease threat in the midst of the slowly relenting COVID-2019 disease pandemic. The hallmark of infection is the development of a flu-like prodrome followed by the appearance of a smallpox-like exanthem. Precipitous person-to-person transmission of the virus among residents of 100 countries where it is nonendemic has motivated the immediate and widespread implementation of public health countermeasures. In this review, we discuss the origins and virology of monkeypox virus, its link with smallpox eradication, its record of causing outbreaks of human disease in regions where it is endemic in wildlife, its association with outbreaks in areas where it is nonendemic, the clinical manifestations of disease, laboratory diagnostic methods, case management, public health interventions, and future directions.

취약존재의 생산

This article focuses on disease experience and its containment policy in South Korea. In particular, the outbreak of Covid-19 shifts the main idea of how to control the disease. Koreans experienced repeated and cyclic outbreaks of human and animal infectious diseases since the beginning of the new millennium. The experiences reflected in the containment policy in human and animal diseases. This research is interested in a fact that the public health policy produces new vulnerable beings, which include humans(migrant and part-time workers) and non-humans(domestic and wild animals) through preventive culling and spatialized approach to contain infectious diseases. Aggressive and centralized policy outsources risks of diseases onto vulnerable beings. Although global health organizations have put forward the concept of ‘One Health’, a holistic and interdisciplinary approach to solve the problem and promote health of humans, animals and the ecosystem, it is not suffice to stop from producing those vulnerable beings. This article shows how the space-based containment has been adopted as a public health strategy, and how the vulnerabilities of humans and animals in ecosystems were intensified in the process of disease prevention even in the One Health frame.

Improvement of native structure-based peptides as efficient inhibitors of protein-protein interactions of SARS-CoV-2 spike protein and human ACE2.

New pathogens responsible for novel human disease outbreaks in the last two decades are mainly the respiratory system viruses. Not different was the last pandemic episode, caused by infection of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). One of the extensively explored targets, in the recent scientific literature, as a possible way for rapid development of COVID-19 specific drug(s) is the interaction between the receptor-binding domain of the virus’ spike (S) glycoprotein and human receptor angiotensin-converting enzyme 2 (hACE2). This protein-protein recognition process is involved in the early stages of the SARS-CoV-2 life cycle leading to the host cell membrane penetration. Thus, disrupting this interaction may block or significantly reduce the infection caused by the novel pathogen. Previously we have designed (by in silico structure-based analysis) three very short peptides having sequences inspirited by hACE2 native fragments, which effectively bind to the SARS-CoV-2 S protein and block its interaction with the human receptor. In continuation of the above mentioned studies, here we presented an application of molecular modeling approach resulting in improved binding affinity of the previously proposed ligand and its enhanced ability to inhibit meaningful host-virus protein-protein interaction. The new optimized hexapeptide binds to the virus protein with affinity one magnitude higher than the initial ligand and, as a very short peptide, has also great potential for further drug development. The peptide-based strategy is rapid and cost-effective for developing and optimizing efficient protein-protein interactions disruptors and may be successfully applied to discover antiviral candidates against other future emerging human viral infections.

Epidemiological Trends of Human Monkeypox Cases in Northern, Southern, Western, and Eastern Regions in Europe: A Cross-Sectional Study.

Background The growing amount of monkeypox cases in non-endemic regions raises concerns in societies as a potential pandemic. This study highlights the prevalence and epidemiological trends of a human monkeypox outbreak in various regions in Europe. Methods This cross-sectional study was conducted in the Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia. The data about the monkeypox outbreak in European countries were recorded by the World Health Organization (WHO), and Centers for Disease Control and Prevention (CDC) reports. The period prevalence-based data were recorded from Jan 1, 2022, to July 7, 2022, and analyzed, and epidemiological trends were established in different European regions and countries. Results In Europe, the human monkeypox rapidly spread in all the four subregions and involved 30 European countries, infecting 6077 people. The rising number of monkeypox cases is identified in Western Europe, 2599 (42.76%); Southern Europe, 1932 (31.79%); Northern Europe, 1487 (24.46%); and Eastern Europe, 59 (0.97%). In Western Europe, significant cases are found in Germany (1304), France (604), the Netherlands (352), Belgium (168), and Switzerland (131). In Northern Europe, it is found in the United Kingdom (1351), Ireland (44), Sweden (28), and Denmark (26); in Southern Europe, it is found in Spain (1256), Portugal (415), and Italy (233). However, a smaller number of cases are found in Eastern European states, Hungary (22), Poland (13), and Romania (12). The results further revealed that the number of monkeypox cases per million people in Northern Europe was 14.40%; Southern Europe, 13.49%; Western Europe, 13.26%; and Eastern Europe, 0.70%. The highest monkeypox cases per million population are found in Portugal, 40.70; Gibraltar, 29.68; Spain, 26.86; the United Kingdom, 19.90; Malta, 18.12; the Netherlands, 20.54; Germany, 15.56; Switzerland, 15.14; Belgium, 14.50; France, 9.27; and Ireland, 8.90. Conclusions In a short period, the monkeypox cases swiftly spread in 30 non-endemic European countries and involved all four European regions. The healthcare authorities must take timely decisions to control the outbreak of human monkeypox disease, as the world cannot afford the global burden of human monkeypox outbreak as another potential pandemic.

Measles and Nipah virus assembly: Specific lipid binding drives matrix polymerization.

Measles virus, Nipah virus, and multiple other paramyxoviruses cause disease outbreaks in humans and animals worldwide. The paramyxovirus matrix (M) protein mediates virion assembly and budding from host cell membranes. M is thus a key target for antivirals, but few high-resolution structures of paramyxovirus M are available, and we lack the clear understanding of how viral M proteins interact with membrane lipids to mediate viral assembly and egress that is needed to guide antiviral design. Here, we reveal that M proteins associate with phosphatidylserine and phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] at the plasma membrane. Using x-ray crystallography, electron microscopy, and molecular dynamics, we demonstrate that PI(4,5)P2 binding induces conformational and electrostatic changes in the M protein surface that trigger membrane deformation, matrix layer polymerization, and virion assembly.

First detection of avian influenza subtype H4N6 in Israel in a wild mallard (Anas platyrhynchos).

Avian influenza viruses (AIV) are a worldwide threat to animal and human health. As wild waterfowl circulate and spread these viruses around the world, investigations of AIV prevalence in wild populations are critical for understanding pathogen transmission, as well as predicting disease outbreaks in domestic animals and humans. Surveillance efforts in this study have isolated H4N6 for the first time in Israel from a faecal sample of a wild mallard (Anas platyrhynchos). Phylogenetic analyses of the HA and NA genes revealed that this strain is closely related to isolates from Europe and Asia. This Eurasian origin, together with Israel serving as an important migratory bottleneck of the mid Palearctic-African flyway, suggests a potential introduction of this strain by migratory birds. Additional phylogenetic analysis of the isolate's internal genes (PB1, PB2, PA, NP, M and NS) revealed high levels of phylogenetic relatedness with other AIV subtypes, indicating previous reassortment events. High reassortment rates are characteristic for H4N6 viruses, which, together with this subtype's ability to infect pigs and adaptability to the human receptor binding domain, raises the concern that it would potentially become zoonotic in the future. These results emphasize the importance of continuous AIV monitoring in migratory birds.