influenza viruses
Flu Illness
Australia Beefs Up Battle Against Swine Flu
Real-time reverse transcription polymerase chain reaction (RRT-PCR) is commonly used for the rapid detection, as well as to determine the subtype, of avian viruses (AIVs). There are 16 known serologically distinct hemagglutinin (HA) subtypes of AIV described.A subtyping assay for both the hemagglutinin (HA) and neuraminidase (NA) surface antigens of the avian influenza virus (AIV) has been developed. The method uses padlock probe chemistry combined with a microarray output for detection.Efficient and sustained human-to-human transmission is the remaining property that H5N1 avian influenza viruses do not yet have that is needed to cause a pandemic.There is an urgent need to develop novel approaches to vaccination against the emerging, highly pathogenic avian influenza viruses. Neutralising activity of S2 sera from mice immunised with Flu-VLPs incorporating the HA, NA and M2 proteins from H7N1 (lanes 1–8) or H5N1 (lanes 13–20) influenza viruses (H7-VLP and H5-VLP,Brief review of influenza virus structure and properties It appears that some animal, somewhere (possibly a pig), becomes infected with both human and animal viruses, and that one of the reassortants contains genes for human internal components but a new HA and/or NA segment from the animal virus.Systemic symptoms result from inflammatory mediators, similar to other viruses. The incubation period of ranges from 18-72 hours.Citation: Jones, Y., Swayne, D.E.
2004. Comparative Pathobiology of Low and High Pathogenicity H7N3 Chilean Avian Viruses in Chickens. Avian Diseases 48(1):119-128, 2004.During the budding of enveloped viruses from the plasma membrane, the lipids are not randomly incorporated into the envelope, but virions seem to have a lipid composition different from This biochemical behavior suggests that so-called raft-lipid domains are selectively incorporated into the virus envelope.So, you may or may not be aware of the latest According to Wells, he's made a bizarre claim: that the fact that viruses haven't evolved resistance to UV light is evidence for design. I thought that Casey Luskin's piece on intelligent design and flu was as bad as it gets, but I think this is a toss-up;NIH Funding Opportunities and Notices in the NIH Guide for Grants and Contracts: Studies to Understand Transmissibility of Influenza Viruses in Mammalian Species RFA-CI-06-004. NCID Title: Studies to Understand Transmissibility of Viruses in Mammalian Species We tested this hypothesis by estimating rates of nucleotide substitution in a diverse array of avian viruses (AIV) and allowing for rate variation among lineages.
Influenza virus (an Orthomyxovirus) is responsible for acute upper respiratory disease, usually accompanied by fever and myalgia. ; Virions are usually roughly spherical and about 200nm in diameter. The envelope contains rigid "spikes" of haemagglutinin and neuraminidase which form a characteristic halo of A pandemic is a global disease outbreak. H1N1 are not transmitted by food. You cannot get H1N1 influenza from eating pork or pork products.
Eating properly handled and cooked pork and pork products is safe. Cooking pork to an internal temperature of 160°F kills the H1N1 flu virus as it does Technical overview of the virus, including the various types, the history of human infection, and ways to prevent and treat the illness. Birds appear to be the source. Both the H2 that appeared in 1957 and the H3 that appeared in 1968 came from influenza viruses circulating in birds.Orthomyxoviruses - influenza. Influenza B viruses infect mammals only and cause disease, but generally not as severe as A types.
Unlike influenza A viruses, B viruses do not have distinguishable serotypes.To assess the pandemic risk that avian influenza viruses pose, we have used multiple strategies to better understand the capacity of avian viruses to infect, cause disease, and transmit among mammals, including humans.BIRD FLU INFECTING A PERSON: graphic artwork (above) showing avian influenza viruses (H5N1 shown in green) infecting a person (with lungs and other organs visible). H5N1 seems to provoke an extreme immune response (a cytokine storm) which might account for the very high death rate from this strain.Wild migratory birds may be more important carriers of avian influenza viruses from continent to continent than previously thought, according to new scientific research that has important implications for highly pathogenic avian virus surveillance in North America. Contact Information: U.S.However, more research is needed in the discovery of novel vaccines, adjuvants, and dosing regimens to be able to supply the world with a safe and effective vaccine against avian viruses. Weekly Update Weekly Influenza Sentinel Surveillance Reports. Weekly Update 2005/31Agent; Environmental Survival of Avian Viruses; Avian Influenza: Brief Background; Laboratory Testing for Avian Influenza in Humans; Summary of Avian in Humans; The Current Outbreak of H5N1 in Birds and Other Animals; H5N1 in Humans: Epidemiologic Features; H5N1 in Humans: Clinical Features;Avian influenza infections by high and low pathogenicity H7 influenza viruses have caused several outbreaks in European poultry in recent years, also resulting in human infections.Avian influenza infections by high and low pathogenicity H7 viruses have caused several outbreaks in European poultry in recent years, also resulting in human infections.Yahoo! reviewed these sites and found them related to CDC - Influenza (Flu) | The Disease; Information resources about influenza (the flu), a contagious respiratory illness caused by influenza viruses.
Includes key facts, symptoms, and general information about how flu spreads.While conjunctivitis may be associated with human infection with some avian viruses (20, 21), ocular infection does not appear to be a primary route for transmission of human influenza viruses, although data are very limited.Signs of drug resistance found in African H5N1 viruses Characterization of conserved properties of hemagglutinin of H5N1 and human viruses: possible consequences for therapy and infection control Wild waterfowl in Canada and throughout the world are natural carriers of influenza viruses. These viruses typically cause little or no harm to the birds. Periodically these viruses can spread to domestic poultry and, under certain circumstances, to people.The test panel and diagnostic system can detect and identify commonly circulating human influenza viruses as well as A (H5N1) viruses. Results can be available within four hours and the system can test multiple samples at once.Influenza are highly unstable. The co-circulation of highly pathogenic animal viruses with human viruses could create opportunities for different species-specific viruses to exchange genetic material, giving rise to a new influenza virus to which humans would have little, if any, protective immunity.Phylogenetic analysis groups the influenza viruses in wild aquatic birds into two distinct superfamilies—one in the Americas and one in Eurasia.
The separation of viruses into American and Eurasian clades implies that transmission of HP H5 into the Americas by wild birds EVOLUTION OF INFLUENZA A VIRUSES IN WILD BIRDS1 The virus is a class of viruses containing RNA as its hereditary material. It replicates by entering a host cell and using this cell's resources to produce hundreds of copies of the viral RNA.Types of Influenza Viruses; A and B viruses are responsible for seasonal flu epidemics each year … Transmission of Influenza Viruses from Animals to People; Influenza A viruses are found in many different animals, including ducks, chickens, pigs, whales, horses and seals. B viruses circulate Avian Influenza A Viruses Influenza that infect birds are called avian influenza viruses. Only A viruses infect birds, and all known subtypes of influenza A viruses can infect birds. However, there are substantial genetic differences between the subtypes that typically infect both people and birds.Influenza, commonly known as the flu, is an infectious disease that affects birds and mammals caused by RNA viruses of the family Orthomyxoviridae (the influenza viruses).
The name comes from the Italian: influenza, meaning "influence", (Latin: influentia).H1N1 is a subtype of the species Influenza A virus. H1N1 has mutated into various strains including the Spanish Flu strain (now extinct in the wild), mild human flu strains, endemic pig strains, and various strains found in birds.Major difficulties with this expression exist, largely because it is ambiguous, and because all influenza A viruses have a host in birds. The MeSH section has created eight new influenza A virus headings and deleted three older ones. The deleted headings are INFLUENZA A VIRUS, AVIAN; INFLUENZA A VIRUS, HUMAN;All the viral genes were of avian influenza origin, which indicates absence of reassortment with human influenza viruses. All human H5N1 isolates tested belonged to a single clade and were resistant to the adamantane drugs but sensitive to neuraminidase inhibitors.Brief review of influenza virus structure and properties It appears that some animal, somewhere (possibly a pig), becomes infected with both human and animal viruses, and that one of the reassortants contains genes for human internal components but a new HA and/or NA segment from the animal virus.This study is a description of the previously uncharacterized H9N2 avian influenza viruses recently circulating in chickens and ducks in Mainland China.
Our findings suggest that urgent attention should be paid to the control of H9N2 influenza viruses in animals and to the human's pandemic preparedness.The Big Picture Book of Viruses: Orthomyxoviridae several viruses Influenza A virus (Medical Journal of Australia) The influenza viruses Aquatic birds are the evolutionary hosts of viruses; they harbour many distinct forms or subtypes of influenza A, which are usually present as harmless gut infections.This finding is important if conclusions about the potential binding sites of SAα2,3 binding viruses, such as influenza or human parainfluenza are to be made What is the difference between low pathogenic and highly pathogenic avian viruses? Most avian influenza viruses are of low pathogenicity, meaning that they do not cause serious disease in birds. Wild birds (ducks, geese and gulls, in particular) often carry these viruses without showing any symptoms.Observed oseltamivir resistance in seasonal influenza viruses in Europe interpretation and potential implications Influenza seasons in which H1N1 viruses predominate are typically associated with less severe illness and lower overall mortality than seasons in which other A viruses predominant.However, while the A/H3 strains are few this season, around one third of specimens tested are influenza B viruses. As noted in the ECDC’s interim risk assessment [4], the appearance of resistant viruses does not seem Oseltamivir resistance in human seasonal viruses (A/H1N1) in EU and EFTA countries: an update From molecules to physiology If highly pathogenic H5N1 influenza viruses acquire affinity for human rather than avian respiratory epithelium, will their susceptibility to neuraminidase (NA) inhibitors (the likely first line of defense against an influenza pandemic) change as well?Free Online Library: H5N1 viruses in Lao People's Democratic Republic. by "Emerging Infectious Diseases"; Health, general Epidemics Laos Research Influenza viruses Causes of Diagnosis ; A prospective surveillance program for influenza viruses was established in Lao People's Democratic Republic (PDR Free Online Library: Antiviral response in pandemic influenza viruses.(INFLUENZA: PATHOGENESIS) by "Emerging Infectious Diseases"; Health, general Antiviral agents Usage Epidemics Development and progression Influenza viruses Drug therapy In influenza viruses, the nonstructural protein 1 inhibits the interferon Real-time reverse transcription polymerase chain reaction (RRT-PCR) is commonly used for the rapid detection, as well as to determine the subtype, of avian viruses (AIVs). There are 16 known serologically distinct hemagglutinin (HA) subtypes of AIV described.The complete genetic coding sequences of 150 different avian influenza viruses have been released.
The information improves scientific understanding of avian influenza, a virus that mainly infects birds but that can also infect humans. The information improves scientific understanding of avian influenza, a virus that Database search, browse, sequence analysis viruses belong to the family Orthomyxoviridae. The viral particles are about 80-120 nm in diameter and can be spherical or pleomorphic. They have a lipid membrane envelope that contains the two glycoproteins: hemagglutinin (HA) and neuraminidase (NA).Geographic spread of highly pathogenic avian H5N1 influenza viruses may give rise to an influenza pandemic. During the first months of a pandemic, control measures would rely mainly on antiviral drugs, such as the neuraminidase (NA) inhibitors oseltamivir and zanamivir.Influenza A virus (IAV) infections are a major cause of respiratory disease of humans and animals.
Pigs can serve as important intermediate hosts for transmission of avian IAV strains to humans, and for the generation of reassortant strains; Influenza A virus (IAV) infections are a major cause of respiratory disease of humans and animals. Pigs can serve as important intermediate hosts for transmission of avian IAV strains to humans, and for the generation of reassortant strains;Further reassortment of genotype E with other aquatic avian viruses gave rise to the genotypes X0−X3, distinguished by the sources of their PB2, PA, and NS genes. Genotype W differs from genotype B only in its PB2, NP, and M genes.In 1997, an avian H5N1 influenza virus, A/Hong Kong/156/97 (A/HK/156/97), caused six deaths in Hong Kong, and in 1999, an avian H9N2 influenza virus infected two children in Hong Kong. These viruses and a third avian Thus, zanamivir is efficacious in treating avian influenza viruses that can be transmitted to mammals.Dr. Nabel and his colleagues previously have shown the DNA vaccine approach to be effective against influenza in animal models, including highly pathogenic viruses such as the H5N1 strain and the H1N1 virus that caused the deadly 1918 pandemic.The receptor specificity of viruses is one factor that allows avian influenza viruses to cross the species barrier.
viruses infect cells by binding of hemagglutinin (HA) to the sialyl sugar residue on the host cell surface (Suzuki 2005 ). Different sialic acid (Sia) species and linkages in The receptor specificity of influenza viruses is one factor that allows avian influenza viruses to cross the species barrier. The recent transmissions of avian H5N1 and H9N2 viruses from chickens and/or quails to humans indicate that avian influenza viruses can directly infect humans without an intermediate host,EVOLUTION OF INFLUENZA A VIRUSES IN WILD BIRDS1 Phylogenetic analysis groups the influenza viruses in wild aquatic birds into two distinct superfamilies—one in the Americas and one in Eurasia. The separation of viruses into American and Eurasian clades implies that transmission of HP H5 into the Americas by wild birds The first reports of outbreaks caused by highly pathogenic avian influenza viruses (HPAIV) of H5N1 subtype in 1996 originated from southern China [1]. Systematic surveillances showed that distinct genetic sub-lineages of H5N1 HPAIVs, reflecting on their geographic origin, have been established since then These viruses usually do not infect humans, but in recent years several cases of avian flu infection in humans have been reported.
There are several subtypes of avian A viruses.In addition it has been recognized recently that influenza viruses, which persist in their natural avian host, can directly infect humans. Topics include foot-and-mouth disease virus, Pestivirus, Arteriviridae, Coronaviruses (including SARS), Herpesviridae, Paramyxoviridae, viruses, Reoviridae,Although the routine procedures for the detection of human influenza A viruses described to date, including in vitro virus isolation, immunofluorescence (IF), and PCR-based assays, are powerful tools, they may be less effective for the detection of viruses of avian and porcine origin.Specialized bioinformatic tools to analyze reassortment are not available, which hampers progress in understanding its role in host range, virulence and transmissibility of influenza viruses.Influenza Virology: Current Topics. Topics covered include analysis of RNP, viral entry and intracellular transport, epidemiology, host range and pathogenicity, antivirals, vaccines, H5 viruses. For the influenza viruses, an initial interaction with cell surface carbohydrate is followed by receptor Understanding the evolution of A viruses in humans is important for surveillance and vaccine strain selection. Despite the wealth of data on the molecular evolution of influenza viruses, how the entire genome of influenza A virus evolves during epidemic years is unclear, particularly as past sample sizes Orthomyxoviruses -- Viruses About Influenza in Sweden Prevention and Control from the NCID.
This site includes general information, vaccine and anti-viral data, and current surveillance statistics.We tested this hypothesis by estimating rates of nucleotide substitution in a diverse array of avian influenza viruses (AIV) and allowing for rate variation among lineages.Researchers from Wisconsin and Japan have developed a live vaccine that may protect against both the and human parainfluenza viruses. They report their findings in the June 2005 issue o Infectious Diseases / Bacteria / Viruses News H5 viruses concern world health officials because H5N1 subtype has been spreading throughout chicken flocks and wild birds in Southeast Asia since it emerged in 1997. Between late 2003 and early 2004, outbreaks of highly pathogenic avian H5N1 influenza occurred among poultry in eight Asian countries,Accurately diagnosing influenza A or B solely on clinical criteria is difficult. In addition to overlapping symptoms caused by URTI-type viruses, more serious viruses, The viruses are typed based on these proteins. For example, influenza A subtype H3N2 expresses hemagglutinin 3 and neuraminidase 2.In domestic poultry, infection with avian influenza causes two main forms of disease, distinguished by low and high extremes of virulence.
The so-called “low pathogenic” form commonly causes only mild symptoms (ruffled feathers, a drop in egg production) and may easily go undetected.Tracking A(H5N1) avian viruses; tracking system launched; Influenza Virus Tracking System; Viruses shared with WHO from 2003-2007 [pdf 22kb]; WHO guidance on development of influenza vaccine reference viruses by reverse genetics Home-Use Tests - Cautions in Using Rapid Tests for Detecting Influenza A Viruses A variety of laboratory tests can be used to detect influenza A viruses directly in human clinical specimens. These include viral culture, polymerase chain reaction (PCR)3, immunofluorescence DFA testing, and enzyme immunoassays for Influenza, also known as the flu, is a contagious disease that is caused by influenza viruses. Influenza viruses infect the respiratory tract (nose, throat, and lungs) in humans. The flu is different from a cold, mainly because the symptoms and complications are more severe."Thanks to the expeditious and collaborative efforts of CDC and FDA, the availability of this new test gives us one more tool to keep up with the ever changing nature of viruses." Influenza Virus Resource presents data obtained from the NIAID Influenza Genome Sequencing Project as well as from GenBank, combined with tools for flu sequence analysis and annotation. In addition, it provides links to other resources that contain flu Publications on influenza viruses from the past 2 weeks Influenza, commonly known as the flu, is an infectious disease that affects birds and mammals caused by RNA viruses of the family Orthomyxoviridae (the influenza viruses).
The name comes from the Italian: influenza, meaning "influence", (Latin: influentia).H9N2 avian influenza A viruses are endemic in poultry of many Eurasian countries and have caused repeated human infections in Asia since 1998. To evaluate the potential threat of H9N2 viruses to humans, we investigated the replication and transmission efficiency Table 1. Wild-type influenza viruses used in this study ; Avian Influenza virus glycoproteins restrict virus replication and spread through human airway epithelium at temperatures of the proximal airways.;Context Very little is known about the frequency of generation and transmissibility of B viruses with reduced sensitivity to neuraminidase inhibitors. Furthermore, transmission of resistant virus, whether influenza A or B, has not been recognized to date.Objective To assess the prevalence and transmissibility of B viruses with reduced sensitivity to neuraminidase inhibitors. Conclusions In this population, B viruses with reduced sensitivity to neuraminidase inhibitors do not arise as frequently as resistant A viruses.
However,humans (Fouchier et al., 2004). Three out of four H5N1 human virus isolates from Vietnam had this mutation, but the human virus from Thailand did not, nor did any other avian tested.Rennie P, Bowtell P, Hull D, Charbonneau D, Lambkin-Williams R, Oxford J; No citations for this article were found in PubMed Central. You can also check ISI Web of Science for additional citations (subscription required) Influenza (flu) is a viral infection. People often use the term "flu" to describe any kind of mild illness, such as a cold or a stomach virus, that has symptoms like the flu. But the real flu is The flu is caused by viruses A and B.
There are different strains, or types, of the flu virus every year.The flu (influenza) viruses; viruses are divided into three types, designated A, B, and C. Influenza types A and B are responsible for epidemics of respiratory illness that occur almost every winter and are often associated with increased rates of hospitalization and death.The 2004 outbreaks of H5N1 viruses in Vietnam and Thailand were highly lethal to humans and to poultry; therefore, newly emerging avian A viruses pose a continued threat, not only to avian species but also to humans.These results indicate that the NS1 gene is critical for the pathogenicity of avian influenza virus in chickens, and that the amino acid residue Ala149 correlates with the ability of these viruses to antagonize interferon induction in CEFs.The outbreak of highly pathogenic avian of the H5N1 subtype in Asia, which has subsequently spread to Russia, the Middle East, Europe, and Africa, has put increased focus on the role of wild birds in the persistence of influenza viruses.Isolation and Genetic Characterization of H5N2 Influenza Viruses from Pigs in Korea. J. H. Lee, P.
N. Q. Pascua, M.-S. Song, Y. H.
Baek, C.-J. Kim, H.-W. Choi, M.-H. Sung, R. J.
Webby, R. G. Webster, H. Poo, et al.This article reviews agents that have been shown to have activity against A viruses and discusses their therapeutic potential, and also describes emerging strategies for targeting these viruses.Notably, a number of the same changes have been found in recently circulating, highly pathogenic H5N1 viruses that have caused illness and death in humans and are feared to be the precursors of a new pandemic. The sequence changes identified here may be important in the adaptation of influenza viruses to humans.Appendix B: [ Background on the Biology of Influenza Viruses ]; However, avian viruses have the potential to mutate or reassort and become pandemic viruses; those that can be readily transmitted between humans and those for which the population has little immunity.Recently, pattern of viral attachment (PVA) in human respiratory tract was determined for highly pathogenic avian influenza virus of subtype H5N1.
However, PVA of human influenza viruses and other avian influenza viruses in either humans or experimental animals is unknown.We found that human influenza viruses attached more strongly to human trachea and bronchi than H5N1 virus and attached to different cell types than H5N1 virus. These differences correspond to primary diagnoses of tracheobronchitis for human viruses and diffuse alveolar damage for H5N1 virus.Perspective from The New England Journal of Medicine -- Antiviral Resistance in Viruses -- Implications for Management and Pandemic Response Antiviral Resistance in Viruses — Implications for Management and Pandemic Response;Perspective from The New England Journal of Medicine -- Antiviral Resistance in Influenza Viruses -- Implications for Management and Pandemic Response -- Data Supplement - Audio Interview with Dr. Frederick Hayden on antiviral resistance in viruses.NIH Funding Opportunities and Notices in the NIH Guide for Grants and Contracts: Replication of Highly Pathogenic Avian Influenza Viruses in Swine RFA-CI-06-005. NCID Title: Replication of Highly Pathogenic Avian Influenza Viruses in Swine. .
