Influenza A virus: The type species of the genus INFLUENZAVIRUS A that causes influenza and other diseases in humans and animals. Antigenic variation occurs frequently between strains, allowing classification into subtypes and variants. Transmission is usually by aerosol (human and most non-aquatic hosts) or waterborne (ducks). Infected birds shed the virus in their saliva, nasal secretions, and feces.Influenza, Human: An acute viral infection in humans involving the respiratory tract. It is marked by inflammation of the NASAL MUCOSA; the PHARYNX; and conjunctiva, and by headache and severe, often generalized, myalgia.Influenza in Birds: Infection of domestic and wild fowl and other BIRDS with INFLUENZA A VIRUS. Avian influenza usually does not sicken birds, but can be highly pathogenic and fatal in domestic POULTRY.Influenza A Virus, H5N1 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 5 and neuraminidase 1. The H5N1 subtype, frequently referred to as the bird flu virus, is endemic in wild birds and very contagious among both domestic (POULTRY) and wild birds. It does not usually infect humans, but some cases have been reported.Influenza A Virus, H1N1 Subtype: A subtype of INFLUENZA A VIRUS with the surface proteins hemagglutinin 1 and neuraminidase 1. The H1N1 subtype was responsible for the Spanish flu pandemic of 1918.Influenza Vaccines: Vaccines used to prevent infection by viruses in the family ORTHOMYXOVIRIDAE. It includes both killed and attenuated vaccines. The composition of the vaccines is changed each year in response to antigenic shifts and changes in prevalence of influenza virus strains. The vaccine is usually bivalent or trivalent, containing one or two INFLUENZAVIRUS A strains and one INFLUENZAVIRUS B strain.Influenza A Virus, H3N2 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 3 and neuraminidase 2. The H3N2 subtype was responsible for the Hong Kong flu pandemic of 1968.Hemagglutinin Glycoproteins, Influenza Virus: Membrane glycoproteins from influenza viruses which are involved in hemagglutination, virus attachment, and envelope fusion. Fourteen distinct subtypes of HA glycoproteins and nine of NA glycoproteins have been identified from INFLUENZA A VIRUS; no subtypes have been identified for Influenza B or Influenza C viruses.Influenza B virus: Species of the genus INFLUENZAVIRUS B that cause HUMAN INFLUENZA and other diseases primarily in humans. Antigenic variation is less extensive than in type A viruses (INFLUENZA A VIRUS) and consequently there is no basis for distinct subtypes or variants. Epidemics are less likely than with INFLUENZA A VIRUS and there have been no pandemics. Previously only found in humans, Influenza B virus has been isolated from seals which may constitute the animal reservoir from which humans are exposed.Orthomyxoviridae Infections: Virus diseases caused by the ORTHOMYXOVIRIDAE.Influenza A Virus, H9N2 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 9 and neuraminidase 2. The H9N2 subtype usually infects domestic birds (POULTRY) but there have been some human infections reported.Orthomyxoviridae: A family of RNA viruses causing INFLUENZA and other diseases. There are five recognized genera: INFLUENZAVIRUS A; INFLUENZAVIRUS B; INFLUENZAVIRUS C; ISAVIRUS; and THOGOTOVIRUS.Birds: Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.Influenza A Virus, H7N7 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 7 and neuraminidase 7. The H7N7 subtype produced an epidemic in 2003 which was highly pathogenic among domestic birds (POULTRY). Some infections in humans were reported.Poultry: Domesticated birds raised for food. It typically includes CHICKENS; TURKEYS, DUCKS; GEESE; and others.Neuraminidase: An enzyme that catalyzes the hydrolysis of alpha-2,3, alpha-2,6-, and alpha-2,8-glycosidic linkages (at a decreasing rate, respectively) of terminal sialic residues in oligosaccharides, glycoproteins, glycolipids, colominic acid, and synthetic substrate. (From Enzyme Nomenclature, 1992)Influenza A Virus, H7N9 Subtype: A subtype of INFLUENZA A VIRUS with the surface proteins hemagglutinin 7 and neuraminidase 9. This avian origin virus was first identified in humans in 2013.Influenza A Virus, H5N2 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 5 and neuraminidase 2. The H5N2 subtype has been found to be highly pathogenic in chickens.Hemagglutinins, Viral: Specific hemagglutinin subtypes encoded by VIRUSES.Hemagglutination Inhibition Tests: Serologic tests in which a known quantity of antigen is added to the serum prior to the addition of a red cell suspension. Reaction result is expressed as the smallest amount of antigen which causes complete inhibition of hemagglutination.DucksReassortant Viruses: Viruses containing two or more pieces of nucleic acid (segmented genome) from different parents. Such viruses are produced in cells coinfected with different strains of a given virus.Influenza A Virus, H3N8 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 3 and neuraminidase 8. The H3N8 subtype has frequently been found in horses.Disease Outbreaks: Sudden increase in the incidence of a disease. The concept includes EPIDEMICS and PANDEMICS.Pandemics: Epidemics of infectious disease that have spread to many countries, often more than one continent, and usually affecting a large number of people.Influenza A Virus, H2N2 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 2 and neuraminidase 2. The H2N2 subtype was responsible for the Asian flu pandemic of 1957.Antibodies, Viral: Immunoglobulins produced in response to VIRAL ANTIGENS.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Anseriformes: An order of BIRDS comprising the waterfowl, particularly DUCKS; GEESE; swans; and screamers.Virus Shedding: The expelling of virus particles from the body. Important routes include the respiratory tract, genital tract, and intestinal tract. Virus shedding is an important means of vertical transmission (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).Chickens: Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.Oseltamivir: An acetamido cyclohexene that is a structural homolog of SIALIC ACID and inhibits NEURAMINIDASE.Receptors, Virus: Specific molecular components of the cell capable of recognizing and interacting with a virus, and which, after binding it, are capable of generating some signal that initiates the chain of events leading to the biological response.Influenza A Virus, H7N1 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 7 and neuraminidase 1. This subtype has demonstrated the ability to mutate from a low pathogenic form to a highly pathogenic form in birds. It was responsible for a 1999 outbreak in turkeys in Italy.Influenza A Virus, H1N2 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 1 and neuraminidase 2. It is endemic in both human and pig populations.Antiviral Agents: Agents used in the prophylaxis or therapy of VIRUS DISEASES. Some of the ways they may act include preventing viral replication by inhibiting viral DNA polymerase; binding to specific cell-surface receptors and inhibiting viral penetration or uncoating; inhibiting viral protein synthesis; or blocking late stages of virus assembly.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Viral Proteins: Proteins found in any species of virus.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Vaccinia virus: The type species of ORTHOPOXVIRUS, related to COWPOX VIRUS, but whose true origin is unknown. It has been used as a live vaccine against SMALLPOX. It is also used as a vector for inserting foreign DNA into animals. Rabbitpox virus is a subspecies of VACCINIA VIRUS.Poultry Diseases: Diseases of birds which are raised as a source of meat or eggs for human consumption and are usually found in barnyards, hatcheries, etc. The concept is differentiated from BIRD DISEASES which is for diseases of birds not considered poultry and usually found in zoos, parks, and the wild.Cloaca: A dilated cavity extended caudally from the hindgut. In adult birds, reptiles, amphibians, and many fishes but few mammals, cloaca is a common chamber into which the digestive, urinary and reproductive tracts discharge their contents. In most mammals, cloaca gives rise to LARGE INTESTINE; URINARY BLADDER; and GENITALIA.Virus Cultivation: Process of growing viruses in live animals, plants, or cultured cells.Antigens, Viral: Substances elaborated by viruses that have antigenic activity.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Ferrets: Semidomesticated variety of European polecat much used for hunting RODENTS and/or RABBITS and as a laboratory animal. It is in the subfamily Mustelinae, family MUSTELIDAE.Madin Darby Canine Kidney Cells: An epithelial cell line derived from a kidney of a normal adult female dog.RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.RNA Viruses: Viruses whose genetic material is RNA.Influenza A Virus, H7N3 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 7 and neuraminidase 3. It was first detected in turkeys in Britain in 1963 and there have been several outbreaks on poultry farms since that time. A couple cases of human infections have been reported.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Seasons: Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Vaccines, Inactivated: Vaccines in which the infectious microbial nucleic acid components have been destroyed by chemical or physical treatment (e.g., formalin, beta-propiolactone, gamma radiation) without affecting the antigenicity or immunogenicity of the viral coat or bacterial outer membrane proteins.Vaccination: Administration of vaccines to stimulate the host's immune response. This includes any preparation intended for active immunological prophylaxis.Animals, Wild: Animals considered to be wild or feral or not adapted for domestic use. It does not include wild animals in zoos for which ANIMALS, ZOO is available.Zanamivir: A guanido-neuraminic acid that is used to inhibit NEURAMINIDASE.Genes, Viral: The functional hereditary units of VIRUSES.Amantadine: An antiviral that is used in the prophylactic or symptomatic treatment of influenza A. It is also used as an antiparkinsonian agent, to treat extrapyramidal reactions, and for postherpetic neuralgia. The mechanisms of its effects in movement disorders are not well understood but probably reflect an increase in synthesis and release of dopamine, with perhaps some inhibition of dopamine uptake.Virus Diseases: A general term for diseases produced by viruses.GeeseInfluenza A Virus, H7N2 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 7 and neuraminidase 2. It has been involved in a number of outbreaks in the 21st century on poultry farms and has been isolated a few times in humans.Hemagglutinins: Agents that cause agglutination of red blood cells. They include antibodies, blood group antigens, lectins, autoimmune factors, bacterial, viral, or parasitic blood agglutinins, etc.Virulence: The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Chick Embryo: The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.RNA Replicase: An enzyme that catalyses RNA-template-directed extension of the 3'- end of an RNA strand by one nucleotide at a time, and can initiate a chain de novo. (Enzyme Nomenclature, 1992, p293)Nucleoproteins: Proteins conjugated with nucleic acids.Cross Protection: Protection conferred on a host by inoculation with one strain or component of a microorganism that prevents infection when later challenged with a similar strain. Most commonly the microorganism is a virus.Influenzavirus A: A genus in the family ORTHOMYXOVIRIDAE causing influenza and other diseases in humans and animals. It contains many strains as well as antigenic subtypes of the integral membrane proteins hemagglutinin (HEMAGGLUTININS) and NEURAMINIDASE. The type species is INFLUENZA A VIRUS.Viral Matrix Proteins: Proteins associated with the inner surface of the lipid bilayer of the viral envelope. These proteins have been implicated in control of viral transcription and may possibly serve as the "glue" that binds the nucleocapsid to the appropriate membrane site during viral budding from the host cell.Zoonoses: Diseases of non-human animals that may be transmitted to HUMANS or may be transmitted from humans to non-human animals.Mice, Inbred BALB CVaccines, Attenuated: Live vaccines prepared from microorganisms which have undergone physical adaptation (e.g., by radiation or temperature conditioning) or serial passage in laboratory animal hosts or infected tissue/cell cultures, in order to produce avirulent mutant strains capable of inducing protective immunity.Bird Diseases: Diseases of birds not considered poultry, therefore usually found in zoos, parks, and the wild. The concept is differentiated from POULTRY DISEASES which is for birds raised as a source of meat or eggs for human consumption, and usually found in barnyards, hatcheries, etc.Pneumonia, Viral: Inflammation of the lung parenchyma that is caused by a viral infection.Virus Assembly: The assembly of VIRAL STRUCTURAL PROTEINS and nucleic acid (VIRAL DNA or VIRAL RNA) to form a VIRUS PARTICLE.Cross Reactions: Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.Neutralization Tests: The measurement of infection-blocking titer of ANTISERA by testing a series of dilutions for a given virus-antiserum interaction end-point, which is generally the dilution at which tissue cultures inoculated with the serum-virus mixtures demonstrate cytopathology (CPE) or the dilution at which 50% of test animals injected with serum-virus mixtures show infectivity (ID50) or die (LD50).Defective Viruses: Viruses which lack a complete genome so that they cannot completely replicate or cannot form a protein coat. Some are host-dependent defectives, meaning they can replicate only in cell systems which provide the particular genetic function which they lack. Others, called SATELLITE VIRUSES, are able to replicate only when their genetic defect is complemented by a helper virus.Swine Diseases: Diseases of domestic swine and of the wild boar of the genus Sus.Virology: The study of the structure, growth, function, genetics, and reproduction of viruses, and VIRUS DISEASES.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Simian virus 40: A species of POLYOMAVIRUS originally isolated from Rhesus monkey kidney tissue. It produces malignancy in human and newborn hamster kidney cell cultures.Viral Core Proteins: Proteins found mainly in icosahedral DNA and RNA viruses. They consist of proteins directly associated with the nucleic acid inside the NUCLEOCAPSID.Virus Inactivation: Inactivation of viruses by non-immune related techniques. They include extremes of pH, HEAT treatment, ultraviolet radiation, IONIZING RADIATION; DESICCATION; ANTISEPTICS; DISINFECTANTS; organic solvents, and DETERGENTS.Charadriiformes: An order of BIRDS including over 300 species that primarily inhabit coastal waters, beaches, and marshes. They are comprised of shorebirds, gulls, and terns.Virus Attachment: The binding of virus particles to receptors on the host cell surface. For enveloped viruses, the virion ligand is usually a surface glycoprotein as is the cellular receptor. For non-enveloped viruses, the virus CAPSID serves as the ligand.Rimantadine: An RNA synthesis inhibitor that is used as an antiviral agent in the prophylaxis and treatment of influenza.Sentinel Surveillance: Monitoring of rate of occurrence of specific conditions to assess the stability or change in health levels of a population. It is also the study of disease rates in a specific cohort such as in a geographic area or population subgroup to estimate trends in a larger population. (From Last, Dictionary of Epidemiology, 2d ed)Viral Plaque Assay: Method for measuring viral infectivity and multiplication in CULTURED CELLS. Clear lysed areas or plaques develop as the VIRAL PARTICLES are released from the infected cells during incubation. With some VIRUSES, the cells are killed by a cytopathic effect; with others, the infected cells are not killed but can be detected by their hemadsorptive ability. Sometimes the plaque cells contain VIRAL ANTIGENS which can be measured by IMMUNOFLUORESCENCE.Influenzavirus C: A genus of the family ORTHOMYXOVIRIDAE comprising viruses similar to types A and B but less common, more stable, more homogeneous, and lacking the neuraminidase protein. They have not been associated with epidemics but may cause mild influenza. Influenza C virus is the type species.Hemagglutination, Viral: Agglutination of ERYTHROCYTES by a virus.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.DNA Viruses: Viruses whose nucleic acid is DNA.Plant Viruses: Viruses parasitic on plants higher than bacteria.Respiratory Syncytial Viruses: A group of viruses in the PNEUMOVIRUS genus causing respiratory infections in various mammals. Humans and cattle are most affected but infections in goats and sheep have also been reported.Animal Migration: Periodic movements of animals in response to seasonal changes or reproductive instinct. Hormonal changes are the trigger in at least some animals. Most migrations are made for reasons of climatic change, feeding, or breeding.Respiratory System: The tubular and cavernous organs and structures, by means of which pulmonary ventilation and gas exchange between ambient air and the blood are brought about.PyransAntibodies, Neutralizing: Antibodies that reduce or abolish some biological activity of a soluble antigen or infectious agent, usually a virus.China: A country spanning from central Asia to the Pacific Ocean.Host-Pathogen Interactions: The interactions between a host and a pathogen, usually resulting in disease.Sindbis Virus: The type species of ALPHAVIRUS normally transmitted to birds by CULEX mosquitoes in Egypt, South Africa, India, Malaya, the Philippines, and Australia. It may be associated with fever in humans. Serotypes (differing by less than 17% in nucleotide sequence) include Babanki, Kyzylagach, and Ockelbo viruses.Measles virus: The type species of MORBILLIVIRUS and the cause of the highly infectious human disease MEASLES, which affects mostly children.Cercopithecus aethiops: A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.Virion: The infective system of a virus, composed of the viral genome, a protein core, and a protein coat called a capsid, which may be naked or enclosed in a lipoprotein envelope called the peplos.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Administration, Intranasal: Delivery of medications through the nasal mucosa.Rabies virus: The type species of LYSSAVIRUS causing rabies in humans and other animals. Transmission is mostly by animal bites through saliva. The virus is neurotropic multiplying in neurons and myotubes of vertebrates.Population Surveillance: Ongoing scrutiny of a population (general population, study population, target population, etc.), generally using methods distinguished by their practicability, uniformity, and frequently their rapidity, rather than by complete accuracy.Drug Resistance, Viral: The ability of viruses to resist or to become tolerant to chemotherapeutic agents or antiviral agents. This resistance is acquired through gene mutation.Vero Cells: A CELL LINE derived from the kidney of the African green (vervet) monkey, (CERCOPITHECUS AETHIOPS) used primarily in virus replication studies and plaque assays.Viral Nonstructural Proteins: Proteins encoded by a VIRAL GENOME that are produced in the organisms they infect, but not packaged into the VIRUS PARTICLES. Some of these proteins may play roles within the infected cell during VIRUS REPLICATION or act in regulation of virus replication or VIRUS ASSEMBLY.Reverse Genetics: The use of techniques that produce a functional MUTATION or an effect on GENE EXPRESSION of a specific gene of interest in order to identify the role or activity of the gene product of that gene.Vesicular stomatitis Indiana virus: The type species of VESICULOVIRUS causing a disease symptomatically similar to FOOT-AND-MOUTH DISEASE in cattle, horses, and pigs. It may be transmitted to other species including humans, where it causes influenza-like symptoms.Communicable Diseases, Emerging: Infectious diseases that are novel in their outbreak ranges (geographic and host) or transmission mode.Sialic Acids: A group of naturally occurring N-and O-acyl derivatives of the deoxyamino sugar neuraminic acid. They are ubiquitously distributed in many tissues.Amino Acid Substitution: The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.Recombination, Genetic: Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.Hepatitis B virus: The type species of the genus ORTHOHEPADNAVIRUS which causes human HEPATITIS B and is also apparently a causal agent in human HEPATOCELLULAR CARCINOMA. The Dane particle is an intact hepatitis virion, named after its discoverer. Non-infectious spherical and tubular particles are also seen in the serum.Host Specificity: The properties of a pathogen that makes it capable of infecting one or more specific hosts. The pathogen can include PARASITES as well as VIRUSES; BACTERIA; FUNGI; or PLANTS.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Hong Kong: The former British crown colony located off the southeast coast of China, comprised of Hong Kong Island, Kowloon Peninsula, and New Territories. The three sites were ceded to the British by the Chinese respectively in 1841, 1860, and 1898. Hong Kong reverted to China in July 1997. The name represents the Cantonese pronunciation of the Chinese xianggang, fragrant port, from xiang, perfume and gang, port or harbor, with reference to its currents sweetened by fresh water from a river west of it.West Nile virus: A species of FLAVIVIRUS, one of the Japanese encephalitis virus group (ENCEPHALITIS VIRUSES, JAPANESE). It can infect birds and mammals. In humans, it is seen most frequently in Africa, Asia, and Europe presenting as a silent infection or undifferentiated fever (WEST NILE FEVER). The virus appeared in North America for the first time in 1999. It is transmitted mainly by CULEX spp mosquitoes which feed primarily on birds, but it can also be carried by the Asian Tiger mosquito, AEDES albopictus, which feeds mainly on mammals.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Parainfluenza Virus 1, Human: A species of RESPIROVIRUS also called hemadsorption virus 2 (HA2), which causes laryngotracheitis in humans, especially children.Virus Activation: The mechanism by which latent viruses, such as genetically transmitted tumor viruses (PROVIRUSES) or PROPHAGES of lysogenic bacteria, are induced to replicate and then released as infectious viruses. It may be effected by various endogenous and exogenous stimuli, including B-cell LIPOPOLYSACCHARIDES, glucocorticoid hormones, halogenated pyrimidines, IONIZING RADIATION, ultraviolet light, and superinfecting viruses.Respiratory Tract Infections: Invasion of the host RESPIRATORY SYSTEM by microorganisms, usually leading to pathological processes or diseases.Genome, Viral: The complete genetic complement contained in a DNA or RNA molecule in a virus.Hemagglutination Tests: Sensitive tests to measure certain antigens, antibodies, or viruses, using their ability to agglutinate certain erythrocytes. (From Stedman, 26th ed)N-Acetylneuraminic Acid: An N-acyl derivative of neuraminic acid. N-acetylneuraminic acid occurs in many polysaccharides, glycoproteins, and glycolipids in animals and bacteria. (From Dorland, 28th ed, p1518)Viral Load: The quantity of measurable virus in a body fluid. Change in viral load, measured in plasma, is sometimes used as a SURROGATE MARKER in disease progression.Epidemics: Sudden outbreaks of a disease in a country or region not previously recognized in that area, or a rapid increase in the number of new cases of a previous existing endemic disease. Epidemics can also refer to outbreaks of disease in animal or plant populations.Turkeys: Large woodland game BIRDS in the subfamily Meleagridinae, family Phasianidae, order GALLIFORMES. Formerly they were considered a distinct family, Melegrididae.Gene Expression Regulation, Viral: Any of the processes by which cytoplasmic factors influence the differential control of gene action in viruses.Nasopharynx: The top portion of the pharynx situated posterior to the nose and superior to the SOFT PALATE. The nasopharynx is the posterior extension of the nasal cavities and has a respiratory function.Disease Transmission, Infectious: The transmission of infectious disease or pathogens. When transmission is within the same species, the mode can be horizontal or vertical (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Myxovirus Resistance Proteins: Interferon-induced DYNAMIN-like GTP-binding proteins localized in the cytoplasm, nuclear pore complex and nucleus. They play a role in antiviral defense and immunity.VietnamMutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Genetic Variation: Genotypic differences observed among individuals in a population.Enzyme-Linked Immunosorbent Assay: An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.Cytopathogenic Effect, Viral: Visible morphologic changes in cells infected with viruses. It includes shutdown of cellular RNA and protein synthesis, cell fusion, release of lysosomal enzymes, changes in cell membrane permeability, diffuse changes in intracellular structures, presence of viral inclusion bodies, and chromosomal aberrations. It excludes malignant transformation, which is CELL TRANSFORMATION, VIRAL. Viral cytopathogenic effects provide a valuable method for identifying and classifying the infecting viruses.Epitopes: Sites on an antigen that interact with specific antibodies.Genetic Vectors: DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Respiratory Syncytial Virus Infections: Pneumovirus infections caused by the RESPIRATORY SYNCYTIAL VIRUSES. Humans and cattle are most affected but infections in goats and sheep have been reported.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Virus Latency: The ability of a pathogenic virus to lie dormant within a cell (latent infection). In eukaryotes, subsequent activation and viral replication is thought to be caused by extracellular stimulation of cellular transcription factors. Latency in bacteriophage is maintained by the expression of virally encoded repressors.DelawareDNA Primers: Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.Immunization: Deliberate stimulation of the host's immune response. ACTIVE IMMUNIZATION involves administration of ANTIGENS or IMMUNOLOGIC ADJUVANTS. PASSIVE IMMUNIZATION involves administration of IMMUNE SERA or LYMPHOCYTES or their extracts (e.g., transfer factor, immune RNA) or transplantation of immunocompetent cell producing tissue (thymus or bone marrow).Polysorbates: Sorbitan mono-9-octadecanoate poly(oxy-1,2-ethanediyl) derivatives; complex mixtures of polyoxyethylene ethers used as emulsifiers or dispersing agents in pharmaceuticals.Vaccines, Synthetic: Small synthetic peptides that mimic surface antigens of pathogens and are immunogenic, or vaccines manufactured with the aid of recombinant DNA techniques. The latter vaccines may also be whole viruses whose nucleic acids have been modified.Serial Passage: Inoculation of a series of animals or in vitro tissue with an infectious bacterium or virus, as in VIRULENCE studies and the development of vaccines.Antigenic Variation: Change in the surface ANTIGEN of a microorganism. There are two different types. One is a phenomenon, especially associated with INFLUENZA VIRUSES, where they undergo spontaneous variation both as slow antigenic drift and sudden emergence of new strains (antigenic shift). The second type is when certain PARASITES, especially trypanosomes, PLASMODIUM, and BORRELIA, survive the immune response of the host by changing the surface coat (antigen switching). (From Herbert et al., The Dictionary of Immunology, 4th ed)Thailand: Formerly known as Siam, this is a Southeast Asian nation at the center of the Indochina peninsula. Bangkok is the capital city.Hemadsorption: A phenomenon manifested by an agent or substance adhering to or being adsorbed on the surface of a red blood cell, as tuberculin can be adsorbed on red blood cells under certain conditions. (Stedman, 25th ed)Semliki forest virus: A species of ALPHAVIRUS isolated in central, eastern, and southern Africa.Mice, Inbred C57BLSimian immunodeficiency virus: Species of the genus LENTIVIRUS, subgenus primate immunodeficiency viruses (IMMUNODEFICIENCY VIRUSES, PRIMATE), that induces acquired immunodeficiency syndrome in monkeys and apes (SAIDS). The genetic organization of SIV is virtually identical to HIV.Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Antibody Formation: The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.Viral Tropism: The specificity of a virus for infecting a particular type of cell or tissue.Disease Reservoirs: Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (DISEASE VECTORS) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks.Sequence Homology: The degree of similarity between sequences. Studies of AMINO ACID SEQUENCE HOMOLOGY and NUCLEIC ACID SEQUENCE HOMOLOGY provide useful information about the genetic relatedness of genes, gene products, and species.Specific Pathogen-Free Organisms: Animals or humans raised in the absence of a particular disease-causing virus or other microorganism. Less frequently plants are cultivated pathogen-free.Seroepidemiologic Studies: EPIDEMIOLOGIC STUDIES based on the detection through serological testing of characteristic change in the serum level of specific ANTIBODIES. Latent subclinical infections and carrier states can thus be detected in addition to clinically overt cases.Oncogenic Viruses: Viruses that produce tumors.United StatesMumps virus: The type species of RUBULAVIRUS that causes an acute infectious disease in humans, affecting mainly children. Transmission occurs by droplet infection.Adjuvants, Immunologic: Substances that augment, stimulate, activate, potentiate, or modulate the immune response at either the cellular or humoral level. The classical agents (Freund's adjuvant, BCG, Corynebacterium parvum, et al.) contain bacterial antigens. Some are endogenous (e.g., histamine, interferon, transfer factor, tuftsin, interleukin-1). Their mode of action is either non-specific, resulting in increased immune responsiveness to a wide variety of antigens, or antigen-specific, i.e., affecting a restricted type of immune response to a narrow group of antigens. The therapeutic efficacy of many biological response modifiers is related to their antigen-specific immunoadjuvanticity.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Communicable Disease Control: Programs of surveillance designed to prevent the transmission of disease by any means from person to person or from animal to man.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Horses: Large, hoofed mammals of the family EQUIDAE. Horses are active day and night with most of the day spent seeking and consuming food. Feeding peaks occur in the early morning and late afternoon, and there are several daily periods of rest.Nasal Mucosa: The mucous lining of the NASAL CAVITY, including lining of the nostril (vestibule) and the OLFACTORY MUCOSA. Nasal mucosa consists of ciliated cells, GOBLET CELLS, brush cells, small granule cells, basal cells (STEM CELLS) and glands containing both mucous and serous cells.CD8-Positive T-Lymphocytes: A critical subpopulation of regulatory T-lymphocytes involved in MHC Class I-restricted interactions. They include both cytotoxic T-lymphocytes (T-LYMPHOCYTES, CYTOTOXIC) and CD8+ suppressor T-lymphocytes.Sendai virus: The type species of RESPIROVIRUS in the subfamily PARAMYXOVIRINAE. It is the murine version of HUMAN PARAINFLUENZA VIRUS 1, distinguished by host range.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Respiratory Syncytial Virus, Human: The type species of PNEUMOVIRUS and an important cause of lower respiratory disease in infants and young children. It frequently presents with bronchitis and bronchopneumonia and is further characterized by fever, cough, dyspnea, wheezing, and pallor.Membrane Fusion: The adherence and merging of cell membranes, intracellular membranes, or artificial membranes to each other or to viruses, parasites, or interstitial particles through a variety of chemical and physical processes.Influenzavirus B: A genus of the family ORTHOMYXOVIRUS causing HUMAN INFLUENZA and other diseases primarily in humans. In contrast to INFLUENZAVIRUS A, no distinct antigenic subtypes of hemagglutinin (HEMAGGLUTININS) and NEURAMINIDASE are recognized.Guanidines: A family of iminourea derivatives. The parent compound has been isolated from mushrooms, corn germ, rice hulls, mussels, earthworms, and turnip juice. Derivatives may have antiviral and antifungal properties.North AmericaHeLa Cells: The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.Egypt: A country in northern Africa, bordering the Mediterranean Sea, between Libya and the Gaza Strip, and the Red Sea north of Sudan, and includes the Asian Sinai Peninsula Its capital is Cairo.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Asia: The largest of the continents. It was known to the Romans more specifically as what we know today as Asia Minor. The name comes from at least two possible sources: from the Assyrian asu (to rise) or from the Sanskrit usa (dawn), both with reference to its being the land of the rising sun, i.e., eastern as opposed to Europe, to the west. (From Webster's New Geographical Dictionary, 1988, p82 & Room, Brewer's Dictionary of Names, 1992, p34)Trachea: The cartilaginous and membranous tube descending from the larynx and branching into the right and left main bronchi.Hemagglutination: The aggregation of ERYTHROCYTES by AGGLUTININS, including antibodies, lectins, and viral proteins (HEMAGGLUTINATION, VIRAL).Transfection: The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.Mosaic Viruses: Viruses which produce a mottled appearance of the leaves of plants.Immunity, Innate: The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from the presence of naturally occurring ANTI-INFECTIVE AGENTS, constitutional factors such as BODY TEMPERATURE and immediate acting immune cells such as NATURAL KILLER CELLS.Pharynx: A funnel-shaped fibromuscular tube that conducts food to the ESOPHAGUS, and air to the LARYNX and LUNGS. It is located posterior to the NASAL CAVITY; ORAL CAVITY; and LARYNX, and extends from the SKULL BASE to the inferior border of the CRICOID CARTILAGE anteriorly and to the inferior border of the C6 vertebra posteriorly. It is divided into the NASOPHARYNX; OROPHARYNX; and HYPOPHARYNX (laryngopharynx).
"Human influenza virus" usually refers to those subtypes that spread widely among humans. H1N1, H1N2, and H3N2 are the only ... C]ontemporary human H3N2 influenza viruses are now endemic in pigs in southern China and can reassort with avian H5N1 viruses ... H7N7 H7N7 has unusual zoonotic potential. In 2003 in Netherlands 89 people were confirmed to have H7N7 influenza virus ... Variants of Influenzavirus A are identified and named according to the isolate that they are like and thus are presumed to ...
H3N2) clearly arose through reassortment between human and avian viruses, the influenza virus causing the 'Spanish flu' in 1918 ... responsible agency for avian influenza in humans in US - Facts About Avian Influenza (Bird Flu) and Avian Influenza A (H5N1) ... never previously susceptible to any influenza virus. H5N1 is a subtype of the species Influenza A virus of the Influenzavirus A ... and causing billions of dollars to be spent in flu pandemic preparation and preventiveness H7N7, which has unusual zoonotic ...
H3N2) clearly arose through reassortment between human and avian viruses, the influenza virus causing the 'Spanish flu' in 1918 ... H7N7, which has unusual zoonotic potential and killed one person. *H1N2, which is currently endemic in humans and pigs and ... H5N1 is a subtype of the species Influenza A virus of the Influenzavirus A genus of the Orthomyxoviridae family. Like all other ... Influenza A virus subtype H5N1, also known as A(H5N1) or simply H5N1, is a subtype of the influenza A virus which can cause ...
The first three genera contain viruses that cause influenza in vertebrates, including birds (see also avian influenza), humans ... Influenza A virus Genus: Influenzavirus B Influenza B virus Genus: Influenzavirus C Influenza C virus Genus: Isavirus ... and HA and NA subtype. Examples of the nomenclature are: A/Brisbane/59/2007 (H1N1) A/Moscow/10/99 (H3N2). The type A viruses ... H1N2 is endemic in humans and pigs[citation needed]. H9N2, H7N2, H7N3, H10N7. Influenza B virus is almost exclusively a human ...
Both the H2N2 and H3N2 pandemic strains contained avian flu virus RNA segments. "While the pandemic human influenza viruses of ... has evidence of inhibition of multiple subtypes of influenza A virus in cell culture with Morpholino oligomers from the results ... oligomers targeting the PB1 and NP genes enhance the survival of mice infected with highly pathogenic influenza A H7N7 virus". ... On April 17, 2007, the first US approval for H5N1 influenza vaccine for humans was given. This vaccine made by Sanofi-Aventis ...
October 2007). "Human and avian influenza viruses target different cells in the lower respiratory tract of humans and other ... 2004). "Avian influenza A virus (H7N7) associated with human conjunctivitis and a fatal case of acute respiratory distress ... Influenzavirus A Influenzavirus B Influenzavirus C These viruses are only distantly related to the human parainfluenza viruses ... analysis of human influenza A virus reveals multiple persistent lineages and reassortment among recent H3N2 viruses". PLoS Biol ...
The new subtypes arose in pigs coinfected with avian and human viruses and were soon transferred to humans. Swine were ... H3N2 is a subtype of the viral genus Influenzavirus A, which is an important cause of human influenza. Its name derives from ... Influenza A virus subtype H3N2 (A/H3N2) is a subtype of viruses that causes influenza (flu). H3N2 viruses can infect birds and ... either a Fujian human flu strain of the H3N2 subtype or a Fujian bird flu strain of the H5N1 subtype of the Influenza A virus. ...
"Avian influenza A virus (H7N7) associated with human conjunctivitis and a fatal case of acute respiratory distress syndrome". ... Serotypes or Subtypes Hosts Influenza virus A Influenza A virus* H1N1, H1N2, H2N2, H3N1, H3N2, H3N8, H5N1, H5N2, H5N3, H5N8, ... Influenza CEdit. Main article: Influenzavirus C. The influenza C virus infects humans and pigs, and can cause severe illness ... Mammalian influenza viruses tend to be labile, but can survive several hours in mucus.[55] Avian influenza virus can survive ...
"Human and avian influenza viruses target different cells in the lower respiratory tract of humans and other mammals". The ... "highly pathogenic avian influenza virus of type A of subtype H5N1") causes H5N1 flu, commonly known as "avian influenza" or ... Influenzavirus D. These viruses are only distantly related to the human parainfluenza viruses, which are RNA viruses belonging ... "Avian influenza A virus (H7N7) associated with human conjunctivitis and a fatal case of acute respiratory distress syndrome". ...
"Human and avian influenza viruses target different cells in the lower respiratory tract of humans and other mammals". Am. J. ... "Avian influenza A virus (H7N7) associated with human conjunctivitis and a fatal case of acute respiratory distress syndrome". ... analysis of human influenza A virus reveals multiple persistent lineages and reassortment among recent H3N2 viruses". PLoS Biol ... "highly pathogenic avian influenza virus of type A of subtype H5N1") menimbulkan flu H5N1, yang umumnya dikenal sebagai flu ...
Influenza is a contagious ailment and is easily communicable and thus, requires rapid and accurate diagnosis for infection ... There are fifteen subtypes of influenza viruses, of which H1N1, H2N2, H3N2, H5N1, H7N7 and H1N2 strains outbreaks were reported ... Influenza, commonly known as flu, is a contagious respiratory ailment caused in humans by influenza virus A and influenza virus ... a new influenza strain called Influenza A/H1N1 or swine flu emerged that consolidated genes from human, pig and bird avian ...
... is a contagious respiratory ailment caused in humans by influenza virus A and influenza virus B. There are three types of... ... There are fifteen subtypes of influenza viruses, of which H1N1, H2N2, H3N2, H5N1, H7N7 and H1N2 strains outbreaks were reported ... a new influenza strain called Influenza A/H1N1 or swine flu emerged that consolidated genes from human, pig and bird avian ... Influenza, commonly known as flu, is a contagious respiratory ailment caused in humans by influenza virus A and influenza virus ...
The term "influenza virus" is intended to denote all influenza viruses, and in particular human, avian, equine, porcine and ... H7N7 and H9N2. According to one particular embodiment, the influenza virus is selected from type B, A-H5N1, A-H7N1 and A-H3N2 ... The influenza viruses responsible for pathological conditions in humans are the type A and B influenza viruses. While type B ... the influenza virus may be of type A and in particular correspond to the strains of subtype H1N1, H2N2, H3N2, H4N2, H4N6, H5N1 ...
These data comprised avian influenza (all subtypes), human H3N2, human seasonal H1N1, human H1N1pdm, swine "classical" (CS) ... one cluster of swine CS H1N1 viruses, equine H7N7, canine H3N8, canine H3N2, and bat influenza virus (italics in Table 1), ... Antigenic and genetic characteristics of swine-origin 2009 A(H1N1) influenza viruses circulating in humans. Science 325:197-201 ... The presence of a full-length PA-X protein in avian influenza virus, human H3N2, human 1918 pandemic and seasonal H1N1, swine ...
Disclosed are recombinant chimeric influenza virus vaccines and live attenuated influenza virus (LAIV) vaccines expressing ... and H3N2 viruses in 1968. In addition to the circulating human influenza subtypes, other avian origin influenza viruses ... avian influenza H5N1 viruses in domestic poultry and the increasing numbers of direct transmission of avian viruses to humans ... including H5N1, H7N2, H7N3, H7N7 and H9N2 subtypes have been shown to cause human infections on multiple occasions (Cheung, C. ...
Influenza virus has a large human and economic toll, with seasonal influenza resulting in ∼300,000-500,000 deaths/y worldwide ... Antigenic and genetic characteristics of swine-origin 2009 A(H1N1) influenza viruses circulating in humans. Science 325: 197- ... we detected cross-reactive ADCC-mediating Abs toward avian H5N1 and H7N7 strains in some individuals in the absence of prior ... a 1968 H3N2 virus had robust ADCC-mediating Abs to this strain (36). In our studies, most influenza virus-specific ADCC- ...
Influenza A viruses of subtype H5N1 also caused severe respiratory disease in humans in Hong Kong in 1997 and 2003, including ... H3N2) were caused by influenza viruses harboring HA and NA genes of avian or swine origin (1, 2). Because of the recent ... A highly pathogenic avian influenza A virus of subtype H7N7, closely related to low pathogenic virus isolates obtained from ... Comparative Analysis of Avian Influenza Virus Diversity in Poultry and Humans during a Highly Pathogenic Avian Influenza A ( ...
"Human influenza virus" usually refers to those subtypes that spread widely among humans. H1N1, H1N2, and H3N2 are the only ... C]ontemporary human H3N2 influenza viruses are now endemic in pigs in southern China and can reassort with avian H5N1 viruses ... H7N7 H7N7 has unusual zoonotic potential. In 2003 in Netherlands 89 people were confirmed to have H7N7 influenza virus ... Variants of Influenzavirus A are identified and named according to the isolate that they are like and thus are presumed to ...
3 genetically similar canine influenza virus (H3N2) strains of avian origin (A/canine/Korea/01/2007, A/canine/Korea/02/2007, ... which suggests potential for direct transmission of avian influenza virus (H3N2) from poultry to dogs. Our data provide ... we experimentally infected beagles with this influenza virus (H3N2) isolate. The beagles shed virus through nasal excretion, ... To determine whether the novel canine influenza virus of avian origin was transmitted among dogs, ...
Information about Transmission of Avian Influenza A Viruses Between Animals and People - CDC ... Currently circulating Influenza A subtypes in humans are H3N2 and H1N1 viruses. Examples of different influenza A virus ... For example, if a pig were infected with a human influenza A virus and an avian influenza A virus at the same time, the new ... subtypes that have infected animals to cause outbreaks include H1N1 and H3N2 virus infections of pigs, and H7N7 and H3N8 virus ...
H3N2), and B viruses co-circulated in the Northern Hemisphere. Human infections with avian influenza A (H5N1) and A (H7N7) ... Humans typically have little or no antibody protection against these viruses. If an avian or other animal influenza virus ... were subtyped; of these, 2,534 (75%) were influenza A (H1) viruses, and 847 (25%) were influenza A (H3N2) viruses. Influenza A ... 267 influenza A (H1) viruses, 105 influenza A (H3N2) viruses, and 254 influenza B viruses. Of the 267 influenza A (H1) viruses ...
Influenza is a respiratory infection commonly found in humans, pigs, horses and other poultry and wild birds. It is charact ... Influenza, also known as the flu or grippe, is an infectious viral disease that affects the upper respiratory system, including ... avian H1N1 and human H3N2 strains. Both human influenza viruses and avian influenza viruses have established stable viral ... The avian influenza virus subtypes that can directly infect humans are: H5N1, H7N1, H7N2, H7N3, H7N7, H9N2 and H7N9 subtypes. ...
H3N2) clearly arose through reassortment between human and avian viruses, the influenza virus causing the Spanish flu in 1918 ... responsible agency for avian influenza in humans in US - Facts About Avian Influenza (Bird Flu) and Avian Influenza A (H5N1) ... never previously susceptible to any influenza virus. H5N1 is a subtype of the species Influenza A virus of the Influenzavirus A ... and causing billions of dollars to be spent in flu pandemic preparation and preventiveness H7N7, which has unusual zoonotic ...
Influenza viruses cause a broad array of respiratory illnesses responsible for significant morbidity and mortality in children. ... Influenza is the one of the most significant acute upper respiratory tract infections. ... influenza A subtype H3N2 expresses hemagglutinin 3 and neuraminidase 2. Influenza A subtype H5N1, or avian influenza, has been ... influenza virus types A and B) and sporadic disease (type C) in humans. Seasonal human influenza causes about 36,000 deaths and ...
... highly pathogenic strains of avian influenza virus, including the H5N1 and H7N7 subtypes, again crossed from birds to humans ... current human influenza vaccine was done to reduce the likelihood that the avian virus would reassort with human H1N1 and H3N2 ... the H7N7 virus events occurred in European poultry and humans, H5N1 viruses infected Asian poultry and humans, and novel, ... Influenza experts feared that H5N1 influenza virus had acquired the ominous capacity to pass from human to human. That outbreak ...
Virus: Specific Host Response and Responses Intermediate between Avian (H5N1 and H7N7) and Human (H3N2) Viruses and ... H5N1 influenza viruses are capable of causing severe disease and death in humans, and represent a potential pandemic subtype ... A novel avian-origin H7N9 influenza A virus (IAV) emerged in China in 2013, causing mild to lethal human respiratory infections ... Influenza A Virus, H1N1 Subtype Lipid Metabolism Lung LXR/RXR Macaca Mice Mice, Inbred BALB C Orthomyxoviridae Infections ...
... reassortants between H3N2 CIV and other influenza viruses, including a CIV carrying the M segment of human influenza virus H1N1 ... with an outbreak of an unknown equine influenza virus (EIV) subtype occurring in 1872 (20), an H7N7 EIV that emerged around ... Genetic characterization of avian-origin H3N2 canine influenza viruses isolated from Guangdong during 2006-2012. Virus Genes 46 ... A novel reassortant canine H3N1 influenza virus between pandemic H1N1 and canine H3N2 influenza viruses in Korea. J Gen Virol ...
... avian,influenza,A,virus,has,potential,for,both,virulence,and,transmissibility,in,humans,biological,biology news articles, ... The first report of infections of humans with the influenza A virus of...In the current study investigators focused on the ... virus pattern of a...Using virus histochemical analysis the investigators looked at the pa...,Novel, ... They found that like other avian influenza viruses, the H7N9 viruses attached more strongly to lower parts of the human ...
H5N1 is one of several hundred subtypes of the Type A influenza virus and is not the only one to have infected humans. The H7N7 ... There is already a human H3N2 - a distant cousin of this pig virus - so some way to differentiate the viruses is needed. Pork ... Bird flu, or avian influenza, is an infectious disease that in most cases affects only birds. But a subtype of the virus called ... which is technically known as a swine origin influenza A virus of the H3N2 subtype. The new virus has acquired the M gene of ...
... which has recently emerged in humans, attaches moderately or abundantly to the epithelium of both the upper and lower ... A new study has found that a novel avian-origin H7N9 influenza A virus, ... They found that like other avian influenza viruses, the H7N9 viruses attached more strongly to lower parts of the human ... The first report of infections of humans with the influenza A virus of the subtype H7N9 surfaced in March 2013. Three patients ...
... early detection at the human-animal interface will provide earlier warning. Here we review recent emerging virus treats for ... A number of emerging viruses have been influenza viruses, coronaviruses, enteroviruses, and adenoviruses. As the genesis of ... A number of emerging viruses have been influenza viruses, coronaviruses, enteroviruses, and adenoviruses. As the genesis of ... Here we review recent emerging virus treats for these four groups of viruses. ...
H1N1 and H3N2 subtypes have caused milder to severe eruptions in hogs while H7N7 and H3N8 in Equus caballuss. The human grippe ... Biology of the virus. Influenza viruses belonging to the household Orthomyxoviridae are enveloped viruses ( Lamb and Krug, 2001 ... Humans get infection most frequently through near and frequent contact with domestic birds while managing septic birds and ... For case, the H1N1 avian subtype ( Scholtissek et al. , 1983 ) and H3N2 human subtype ( Tumova et al. , 1980 ; Ottis et al. , ...
Although limited human-to-human transmission of viruses with the H5N1 and H7N7 subtypes has occurred [11-15], these avian ... Avian H5N1/human H3N2 reassortant influenza viruses, which express the HA and NA proteins from an H5N1 virus, exhibited no ... The HAs of avian influenza viruses must adapt to receptors in humans to acquire efficient human-to-human transmissibility. In ... Avian-to-human transmission of H9N2 subtype influenza A viruses: relationship between H9N2 and H5N1 human isolates. Proc Natl ...
Influenza virus which is a RNA virus that is seen in humans, birds, and some mammals. Can be mistaken for the common cold - ... Influenza or The Flu is caused by a ... Subtypes of the Influenza. - Each set of viruses also has ... H3N2 - Hong Kong Flu. - H5N1 - Bird Flu. - H7N7, H1N2, H9N2, H7N3 and others ... Other Flu outbreaks besides Human. - Avian Flu. - Dog Flu. - Swine Flu. - Horse Flu ...
  • We tested heat, formalin, Triton X-100, and β-propiolactone treatments for their potencies in inactivating human influenza A(H3N2) and avian A(H7N3) viruses, as well as seasonal and pandemic A(H1N1) virus isolates, while allowing the specimens to retain their virological and immunological properties. (asm.org)
  • The HA genes of A/Mallard/Netherlands/12/00 (H7N3), A/Chicken/Netherlands/1/03 (H7N7), and A/Netherlands/219/03 (H7N7) are shown. (nih.gov)
  • In particular the study has focused on the evolutionary dynamics and the adaptive strategies of avian influenza H7N1 and H7N3 subtypes that circulated in Northern Italy for similar periods of time under similar epidemiological conditions. (unipd.it)
  • Here, we briefly outline what is known about the role of intermediate hosts in influenza emergence, summarize our knowledge of the new canine influenza viruses (CIVs) and how they provide key new information on the process of host adaptation, and assess the risk these viruses pose to human populations. (asm.org)
  • In addition the efficacy of novel and existing antiviral treatments and the emergence of drug-resistant virus variants are monitored in order to improve antiviral treatment regimens. (molmed.nl)
  • It is well appreciated that interspecies transmission of pathogens may result in the emergence of new infectious diseases in humans and animals. (molmed.nl)
  • Emergence of genetically and antigenically diverse strains of influenza to which the human population has no or limited immunity necessitates continuous risk assessments to determine the likelihood of these viruses acquiring adaptations that facilitate sustained human-to-human transmission. (mdpi.com)
  • These viruses were dominant in swine until the emergence of H3N2 viruses in pigs in the late 1990s. (mdpi.com)
  • This review focuses on ecological and genetic aspects that lead to the emergence of new human zoanthroponous coronaviruses. (bvsalud.org)
  • In collaboration with the World Health Organization (WHO), its collaborating laboratories, state and local health departments, health-care providers, and vital statistic registries, CDC conducts surveillance to monitor influenza activity and to detect antigenic changes in the circulating strains of influenza viruses. (cdc.gov)
  • In 2001, WHO initiated the development of a Global Agenda for Influenza Surveillance and Control. (sciencemag.org)
  • The document advocates the development of methods and reagents that can be used to rapidly identify all influenza virus subtypes, thereby allowing integrated influenza surveillance in humans and in other animals. (sciencemag.org)
  • Although the virus was not as pathogenic to humans as expected, severe disease cases associated with pH1N1 have been more recently reported in England ( http://www.who.int/influenza/surveillance_monitoring/updates/2010_12_30_GIP_surveillance/en/ ). (pubmedcentralcanada.ca)
  • BACKGROUND: While influenza-like-illness (ILI) surveillance is well-organized at primary care level in Europe, few data are available on more severe cases. (flu.org.cn)
  • We demonstrate its usefulness for the rapid detection and surveillance of pandemic H1N1/09 influenza A virus infections. (asm.org)
  • The detection of new human cases of A(H10N8) and A(H6N1) likely reflects enhanced surveillance activities in China and Taiwan. (flutrackers.com)
  • Influenza viruses isolated in national and global surveillance systems are characterized antigenically and genetically to identify variants. (asmscience.org)
  • Despite the limited number of incident cases detected by the surveillance system, A(H1N1)pdm09 virus circulated broadly in Djibouti in 2010 and 2011. (biomedcentral.com)
  • It is important to continue this surveillance of avian influenza viruses to monitor the evolution of circulating viruses. (bvsalud.org)
  • Although there is no formal national surveillance system in the United States to determine what viruses are circulating in pigs, [ 14 ] there is an informal surveillance network in the United States that is part of a world surveillance network. (academic.ru)
  • The draft document was sent to the whole influenza society in the world, including more than 1600 influenza experts and other colleagues from academies, national licensing agencies, pharmaceutical industries and research institutions interested in influenza surveillance and control, for comments. (who.int)
  • The BaliMEI study aims to conduct a five year active surveillance and characterisation of influenza viruses in Bali using an extensive network of participating healthcare facilities. (biomedcentral.com)
  • 9 , 10 ] The Molecular Epidemiology of Influenza A in Bali project ("BaliMEI") [ 11 ] aims to conduct five years of active surveillance and characterisation of influenza viruses in Bali (2010-2015). (biomedcentral.com)
  • The beagles shed virus through nasal excretion, seroconverted, and became ill with severe necrotizing tracheobronchitis and bronchioalveolitis with accompanying clinical signs (e.g., high fever). (cdc.gov)
  • While sometimes confused with the common cold, influenza is a much more severe disease and is caused by a different type of virus. (wikipedia.org)
  • Influenza is currently considered as one of the most severe threats to human health and animal welfare. (biomedcentral.com)
  • The most frequent complication of influenza is pneumonia, with secondary bacterial pneumonia being the most common form, and primary influenza pneumonia the most severe. (influenzareport.com)
  • H5N1 influenza viruses are capable of causing severe disease and death in humans, and represent a potential pandemic subtype should they acquire a transmissible phenotype. (usda.gov)
  • The continued and increasing transmission of a novel reassortant avian influenza virus capable of causing severe disease in humans in one of the most densely populated areas in the world remains a cause for concern due to the pandemic potential. (flutrackers.com)
  • The type A viruses are the most virulent human pathogens among the three influenza types and cause the most severe disease. (wikipedia.org)
  • A few of these infections have been very severe and some have resulted in deaths, but many infections have been mild or even subclinical in humans [ 3 ]. (rroij.com)
  • Aggressive fluid accumulation is associated with acute kidney injury and mortality in a cohort of patients with severe pneumonia caused by influenza A H1N1 virus. (amedeo.com)
  • That suggests many people over the age of 21 probably have some antibodies that could recognize this virus if it starts to spread. (constantcontact.com)
  • Analysis of more than 300 serum samples showed that samples collected early in 2010 (n = 100) were negative and by April animals began to test positive for antibodies against the pH1N1 virus (HI titer of ≥1:40), supporting the molecular findings. (blogspot.com)
  • A fascinating bit of research, published in 2006 in the CDC's EID Journal , looked for avian influenza antibodies in duck hunters and wildlife professionals. (blogspot.com)
  • The prevalence of antibodies against Equine Influenza Virus (EIV) was determined in 529 equines living on ranches in the municipality of Poconé, Pantanal area of Brazil, by means of the hemagglutination inhibition test, using subtype H3N8 as antigen. (bvsalud.org)
  • Equine from non-flooded ranches (66.5%) and negativity in equine infectious anemia virus (EIAV) (61.7%) were associated with antibodies against EIV. (bvsalud.org)
  • The high prevalence of antibodies against EIV detected in this study suggests that the virus is circulating among the animals, and this statistical analysis indicates that the movement and aggregation of animals are factors associated to the transmission of the virus in the region. (bvsalud.org)
  • To better understand the molecular characteristics of these two isolated H7N1 viruses, we sequenced and phylogenetically analyzed their entire genomes. (frontiersin.org)
  • For example, until 1998, only H1N1 viruses circulated widely in the U.S. pig population. (cdc.gov)
  • Mice vaccinated with the group 1 HA mini-stems are protected from morbidity and mortality against lethal challenge by both group 1 (H5 and H1) and group 2 (H3) influenza viruses, the first report of cross-group protection. (nature.com)
  • In more serious cases, influenza causes pneumonia, which can be fatal, particularly in young children and the elderly. (wikipedia.org)
  • 2. Pneumonia caused by a virus will be given treatment similar to flu patients, but more emphasis to the provision of adequate rest and plenty fluid intake and good nutrition to help restore the immune system. (blogspot.com)
  • Images were generated from the crystal structure of HA from A/Aichi/2/1968 (H3N2) virus (PDB code: 2HMG) using PyMOL software. (jimmunol.org)
  • Analysis of these viruses revealed mutations specific to Egyptian strains and not the original virus characterized in 2017 (A/duck/Egypt/F446/2017), with a novel antiviral resistance marker, V27A, indicating resistance to amantadine in the M2 protein of two strains. (bvsalud.org)
  • The results indicate increased variability of circulating H5N8 viruses compared to earlier viruses sequenced in 2016 and 2017. (bvsalud.org)
  • Comparison between influenza coded primary care consultations and national influenza incidence obtained by the General Practitioners Sentinel Network in Portugal from 2012 to 2017. (amedeo.com)
  • Of these 89 patients, 78 presented with conjunctivitis, 5 presented with conjunctivitis and influenza-like illness, 2 presented with influenza-like illness, and 4 did not fit the case definitions. (pnas.org)
  • If this new influenza A virus causes illness in people and is transmitted easily from person to person in a sustained manner, an influenza pandemic can occur. (cdc.gov)
  • Typically, patients may initially recover from the acute influenza illness over 2 to 3 days before having rising temperatures again. (influenzareport.com)
  • 453 people had health complaints-349 reported conjunctivitis, 90 had influenza-like illness, and 67 had other complaints. (n2gf.com)
  • We detected A/H7 in conjunctival samples from 78 (26·4%) people with conjunctivitis only, in five (9·4%) with influenza-like illness and conjunctivitis, in two (5·4%) with influenza-like illness only, and in four (6%) who reported other symptoms. (n2gf.com)
  • All 18 infections involved exposure to swine at agricultural fairs prior to onset of illness and swine at these fairs were found infected with swine influenza A(H3N2) virus. (cdc.gov)
  • The project utilises a network of 21 health facilities across all nine regencies of Bali to collect nasopharyngeal swabs from patients presenting with influenza-like illness. (biomedcentral.com)
  • Type C viruses are less common and cause mild diseases in children. (mynewsdesk.com)
  • Given the mercurial nature of flu viruses- which can easily mutate into lethal pathogens -ignoring the new virus is not an option, even though to date there have been no deaths and most of the infections have produced only mild symptoms. (constantcontact.com)
  • While not used much today, the vaccinia virus is the mild `pox' virus that was used to eradicate smallpox back in the 1970s. (viralinfections.info)
  • Can humans get bird flu? (myantiguabarbuda.com)
  • Whilst on February 12 the Hungary link was dismissed by the European Commission, the H5N1 bird flu strains found in Hungary and Britain are 99.96% genetically identical, and almost certainly linked, according to an analysis of the viruses by the Veterinary Laboratories Agency in Weybridge, Surrey. (bionity.com)
  • Klapper, P. 2014-12-01 00:00:00 Mutations in the haemagglutinin (HA), non-structural protein 1 (NS1) and polymerase basic protein 2 (PB2) of influenza viruses have been associated with virulence. (deepdyve.com)
  • The results suggest that no virus quasispecies bearing virulence-conferring mutations in the HA, PB2 and NS1 predominated. (deepdyve.com)
  • Influenza A viruses should continue to be monitored for the occurrence of virulence-conferring mutations in HA, PB2 and NS1. (deepdyve.com)