Last week marked the 12th consecutive week of elevated flu levels in a season dominated by the influenza a strain h3n2. Influenza d virus in animal species in guangdong province. Influenza viruses are sensitive to lipid solvents and detergents. These pathogen safety data sheets, regulated under workplace hazardous materials information system whmis legislation, are produced for personnel working in the life sciences as quick safety reference material relating to infectious microorganisms. Influenza, or flu, is a contagious respiratory infection caused by several flu viruses that infect the nose, throat and lungs.
Influenza c virus is the species in the genus influenzavirus c, in the virus family orthomyxoviridae, which like other influenza viruses, causes influenza. This work is licensed under a creative commons attribution. Discover when to get flu shots, how long the flu lasts, the contagious period, flu types influenza a, b, and c, and how it spreads. Influenza a virus is a major human pathogen and infects other mammals and birds. Other articles where influenza type a virus is discussed. Mar 10, 2017 the centers for disease control and prevention cdc said today in its weekly influenza surveillance report that influenza has likely peaked in the united states. Molecular tests revealed influenza d viruses of dok lineage widely circulating in farmed animal species in guangdong province, southern china. There have been many achievements in the development of influenza vaccines and antiviral medications to prevent and treat influenza, and there are systems in place to give early warning for the. Three of these, influenzavirus a, influenzavirus b, and influenzavirus c, infect humans. Jul 19, 2010 the current influenza a h1n1 2009 strain is a result of genetic translocation from three different species. Influenza a virus, influenza b virus, and influenza c virus, respectively table 10. Influenza is a highly contagious acute viral infection of the respiratory tract. Influenza a symptoms can be confused with signs of other conditions but are usually.
Influenza in birds is often referred to as avian influenza, in pigs as swine influenza, in horses as equine influenza and so on. Infection occurs at all ages, but during epidemics the morbidity is higher at extremes of life. The viral coats, or outer surfaces, of these viruses contain two major antigenic glycoproteinshemagglutinin h and neuraminidase nwhich differ between influenza a subtypes e. Influenza a is the most dangerous for humans, influenza c is the least dangerous.
Information for specific groups avian influenza flu. The findings challenge a commonly held view that influenza b infections are milder than influenza a in adults. Waterfowl are important reservoirs for many subtypes of influenza. Influenza c virus inhibits the cascade leading to production of interferonbeta by targeting host rigi activation through ns1 protein. In the event of pandemic, a prepandemic cvv can be used to develop a. Influenza a viruses with uncleaved ha are obviously more stable loss of infectivity at ph influenza d viruses circulate among swine and bovine herds in italy affected by respiratory disease. Host virus interaction innate immune response inhibition. Sick patients demand medical care and hospitalization. People infected with the seasonal flu virus feel miserable with fever, chills, muscle aches, coughing, congestion, headache and fatigue for a week or so. Workers in the united states disposing of poultry carcasses during outbreaks of highly pathogenic avian influenza cdc pdf. Information for health professionals and citizens, including state health statistics, prevention and health promotion, and health care and healthrelated professions. Genetic analysis highlights that the swine and bovine influenza d viruses are very closely related, both belonging to the dswineoklahoma342011 cluster.
In a may 2 surveillance update, the cdc said most flu markers continue to show declining activity, but for the one that tracks clinic visits for. Flu due to the type c species is rare compared to types b or a, but can be severe and can cause local epidemics. In particular, we found high levels of influenza d virus infection in goats and pigs. Sep 01, 2016 a new influenza virus that affects cattle has an official name. They are also vulnerable to heat and a low ph, depending on the virus type. Influenza c viruses are known to infect humans and pigs. Type a and b cause the annual influenza epidemics that have up to 20% of the population sniffling, aching, coughing, and running high fevers. New virus gets official name, influenza d sciencedaily.
Dec 27, 2011 animation of the mechanism of an influenza virus and how crucells antibodies target the ha1 proteins on the virus and prevent further spread of influenza. Pdf evolution of influenza a virus by mutation and re. The subtle mutations accumulated through antigenic. Mar 27, 2017 influenza a virus iav membrane proteins hemagglutinin ha and neuraminidase na are determinants of virus infectivity, transmissibility, pathogenicity, host specificity, and major antigenicity.
Dec 21, 2018 type a influenza is a contagious viral infection that can have lifethreatening complications if left untreated. Influenza b is thought to be more deadly to children. Three genera exist with this family that pertain to influenza viruses, influenzavirus a, influenzavirus b, and influenzavirus c, each of which contain a single species, or type. A new influenza virus that affects cattle has an official name influenza d, as proposed by south dakota state university researchers including one of indian origin who discovered it.
A human case of infection with an influenza a virus subtype that is different from currently circulating human influenza h1 and h3 viruses. Influenza b virus is only known to infect humans and seals with influenza. The executive committee of the international committee of taxonomy of virus announced a new genus, orthomyxovirdae. Influenza diagnosis clinical and epidemiological characteristics increase of febrile respiratory illness lab isolation of influenza virus from clinical specimen e. Learn about influenza flu symptoms, treatment with antiviral drugs, flu shot side effects, and prevention during flu season. In addition, we discuss the specific mechanisms by. Novel influenza a virus infections 2010 case definition. Influenza a viruses infect humans and a variety of other wildlife, including. Influenza a virus hemagglutinin and neuraminidase act as. Influenza b virus is primarily a human respiratory virus, but has also been isolated from seals. How any one virus acquires its identification letter depends on differences in the matrix protein, nucleoprotein and response of antibodies to a particular strain. This limited host range is apparently responsible for the lack of associated influenza pandemics in contrast with those caused by the morphologically similar influenza a virus as both mutate by both antigenic drift and reassortment. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext.