In fresh isolates, influenza virus virions are often filamentous rods 300 nm long, while laboratory strains are often 100nmdiameter spheres imai and kawaoka, 2012. Complications of influenza that affect the nervous system include encephalopathy, encephalitis, and reyes syndrome associated with influenza b kuiken et al. Influenza b and c viruses primarily affect humans, and seem to be less likely to cross species barriers. Some isolates of influenza a virus cause severe disease both in domestic poultry and, rarely, in humans. Influenzavirus a definition of influenzavirus a by. The influenza experts at the robert koch institute are constantly monitoring the course of of. The influenza pandemic of 191819, the most destructive influenza outbreak in history read more. The detection or confirmation by a state public health laboratory of an influenza a virus that is unsubtypable with standard methods e. Feb 23, 2012 during the 2011 2012 season, influenza a h3n2, 2009 influenza a h1n1, and influenza b viruses cocirculated in the united states. Influenza situation report pan american health organization. These symptoms typically begin two days after exposure to the virus and most last less than a week.
Epidemiological factors associated with increased odds for influenza included weeks when. The rationale for quadrivalent influenza vaccines ncbi. Influenza, commonly known as the flu, is an infectious disease caused by an influenza virus. We report influenza d virus infection in a herd of cattle in japan. The relative proportion of each circulating type and subtype of influenza virus varied by hhs region and week. Each year in the united states, seasonal influenza, or flu, kills more than 36,000 people and hospitalizes 200,000 more. Behavior of influenza seasons in mexico from 2010 to 2016. Seasonal flu outbreaks are an unfortunate mainstay of the late fall and winter. The substantial global burden of influenza infections in children is. Influenzavirus definition of influenzavirus by the free. Influenza in humans is often referred to as the seasonal flu. Infectious diseases in germany influenza and influenza.
These infections in humans were mostly associated with prolonged exposure to pigs at agricultural fairs. An acute contagious viral infection of humans, characterized by inflammation of the respiratory tract and by fever, chills, muscular pain, and prostration. Equine influenza virus eiv causes common respiratory diseases in horses, donkeys, and mules. Influenzavirus article about influenzavirus by the free. The 2009 influenza pandemic ah1n1pdm09 of swine origin and the continued circulation of highly pathogenic avian h5n1 strain in humans are. Terapia fisica psicoterapia educacion y control del. Influenza activity update a transcript of the 2011 2012 influenza season update telebriefing held on friday, february 23, 2012 at 1pm et. Increased risk of noninfluenza respiratory virus infections. Adenoviral vectorbased influenza vaccines purdue university. Novel influenza a virus infections 2010 case definition. All structured data from the file and property namespaces is available under the creative commons cc0 license. Information on this website is available in alternative formats upon request. Flu goes around every year, with some years being worse than others.
Background paper on influenza vaccines and immunization sage. It most commonly causes a fever and respiratory problems. Influenza a virus causes influenza in birds and some mammals, and is the only species of the genus alphainfluenzavirus of the virus family orthomyxoviridae. This list of resources contains links that can be accessed when viewing the pdf. The subtle mutations accumulated through antigenic. Strains of all subtypes of influenza a virus have been isolated from wild birds, although disease is uncommon. Influenza virus methods and protocols yoshihiro kawaoka. When an influenza a virus undergoes an antigenic shift, a pandemic affecting most of the world can occur within a matter of months. In these individuals, the amount of iiv3induced ifn.
Jun 15, 2012 influenza vaccination is effective in preventing influenza virus infection and associated morbidity among schoolaged children 1, 2. Type c has 7 rna segments and encodes 9 proteins, while types a and b. Impact of preexisting adenovirus vector immunity on immunogenicity and protection conferred with an adenovirusbased h5n1 influenza vaccine. People of all ages can get the flu, from babies and young adults, to the elderly. Burden of influenza in pediatric respiratory hospitalizations, 19822012. Of the four antigenic types, influenza a virus is the most severe, influenza b virus is less severe but can still cause outbreaks, and influenza c virus is usually only associated with minor symptoms. 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 vaccineinduced changes in cellmediated immunity.
Q u im io p r o fila x is t r a ta m ie n to a n tiv ir a l. Department of health and human services centers for disease control and prevention. Influenza in birds is often referred to as avian influenza, in pigs as swine influenza, in horses as equine influenza and so on. Birds, pigs, horses, ferrets, dogs, and cats can all be infected with various strains of the influenza virus. Influenza, also called the flu, is a viral disease that affects humans and many animals. Such events can cause pandemic outbreaks of influenza by the emergence of an avianhuman reassortant virus with the ability to spread rapidly in a nave human and animal populations. The horse population of north america suffered an epidemic of respiratory illnesses in 1872, recorded as the great epizootic of 1872, the cause of which was likely influenza a virus. The potential for temporary nonspecific immunity between respiratory viruses after an infection and consequent interference at the population level between epidemics of these viruses has been hypothesized, with limited empirical evidence to date, mainly. This disease of the brain develops within 212 days of a systemic viral infection, and can result in vomiting, liver damage, coma, and sometimes death. While influenza a h3n2 viruses predominated, 2009 h1n1 and influenza b viruses also circulated throughout the united states. Although the influenza d virus, like the human influenza c virus, is known to use 9oacetylated sialic acids as the cell receptor 2,7, its zoonotic potential is undefined because of limited research 1,8.
Overall, the influenza season was moderate in severity, with high levels of activity in january, february and early march. Some isolates of influenza a virus cause severe disease both in domestic. Influenza viruses are inactivated by sunlight, disinfectants, and detergents, such as sodium deoxycholate and sodium dodecyl sulphate. Most of the influenza b cases were reported during the 201220 season, when the b virus cocirculated with the ah1n1pdm09. Another complication, known as reyes syndrome, may follow influenza, and is more common in children. Of the 23 subjects, 4 developed h3n2 influenza during the study period.
Tracking influenza pdf, 7 mb, file does not meet accessibility standards. In contrast with the 1918 h1n1 influenza virus, the 2009 h1n1 strain was generated by reassortment between two wellestablished swine influenza. This work is licensed under a creative commons attribution. Influenza fact sheet keywords department of health services, dhs, division of public health, influenza, flu, coughing, sneezing, vaccine, vaccination, flu shot, contagious, p42064, p42064 created date. Influenzainduced pneumonia may cause as many as 20,000 deaths in a typical influenza season. In fact, the world health organization who recommendations for the 20112012 northern hemisphere seasonal influenza vaccine formulation already identify.
Influenza viruses a, b, c, and d represent the four antigenic types of influenza viruses. Rki also hosts the german national reference centre for influenza. 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. In the summer of 2012, before the 2012 20 flu season officially began, 307 cases of influenza a h3n2 variant viruses or h3n2v infections were detected across 12 states. Influenza viruses are susceptible to heat, ph extremes, dryness, and are generally unstable in the environment. The 2009 influenza pandemic ah1n1pdm09 of swine origin and the continued circulation of highly pathogenic avian h5n1 strain in humans are stark reminders of the unpredictable nature of the.
Influenza diagnosis clinical and epidemiological characteristics increase of febrile respiratory illness lab isolation of influenza virus from clinical specimen e. Global role and burden of influenza in pediatric respiratory. For most people influenza is just a nasty experience, but for some it can. Influenza, commonly referred to as the flu, is a severe respiratory illness that is easily spread and can lead to severe complications, even death. Influenza type avirus is the most frequent cause of seasonal influenza. Overall, influenza virus activity remained low in the subregion. Effects of vaccine program against pandemic influenza ah1n1. Flu vaccination coverage estimates for the 2011 2012 flu season. Influenza also known as flu is a respiratory illness which is caused by the influenza virus. The rki expert advisory board on influenza was founded in november 2012. Influenza d virus infection in herd of cattle, japan volume. Evaluation of influenza vaccineimmunogenicity in cell.
There are three groups of influenza viruses, called type a, b. By using us surveillance data april 12, 2009april 10, 2010 and vaccine coverage estimates october 3, 2009april 18, 2010, we estimated that the ah1n1pdm09 virus vaccination program prevented 700,0001,500,000 clinical cases. Historia natural influenza ah1n1 by karla martinez castro on. Effects of vaccine program against pandemic influenza a. The recent emergence of avian h5n1, h7n7 and h9n2 influenza viruses in humans has highlighted the ability of at least some avian subtypes to cross the species barrier into humans. Over the last half century, influenza virus research has led to the development of. Equine respiratory diseases were first identified through the isolation of influenza a virus from. Influenza c virus is the species in the genus influenzavirus c, in the virus family orthomyxoviridae, which like other influenza viruses, causes influenza influenza c viruses are known to infect humans and pigs flu due to the type c species is rare compared to types b or a, but can be severe and can cause local epidemics. This page was last edited on 16 december 2019, at 01. Increase influenza vaccination rates in your practice by providing evidencebased interventions for use with vaccinehesitant patients.
Influenza d virus infection in herd of cattle, japan. 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. Pandey a, singh n, vemula sv, couetil l, katz j m, donis r, sambhara s and mittal s. The magnitude of influenza activity as described by the multiple parameters measured percentages of kaiser permanente inpatient. A virus is defined as hpai by its ability to cause severe disease in intravenously inoculated young chickens in the laboratory, or by its possession of certain genetic features that have.
In contrast with the 1918 h1n1 influenza virus, the 2009 h1n1 strain was generated by reassortment between two wellestablished swine influenza lineages, and was a highly virulent amalgam of swine. Over the course of the season, predominant viruses varied from region to region and between states, but nationally, influenza a h3n2 influenza viruses predominated. Files are available under licenses specified on their description page. Influenza vaccination is effective in preventing influenza virus infection and associated morbidity among schoolaged children 1, 2. Other articles where influenza type a virus is discussed. The flu sweeps through communities, creating an epidemic. Influenza viruses are members of the family orthomyxoviridae. Flu vaccination coverage estimates for the 20112012 flu season. Jan 27, 2016 each year in the united states, seasonal influenza, or flu, kills more than 36,000 people and hospitalizes 200,000 more.
Seasonal influenza information for health care providers. In april 2009, the united states began a response to the emergence of a pandemic influenza virus strain. The potential for temporary nonspecific immunity between respiratory viruses after an infection and consequent interference at the population level between epidemics of these viruses has been hypothesized, with limited empirical evidence to date, mainly from. The 2012 flutracking influenza season showed moderate levels of ili, compared with lower levels of ili seen in 2011 and. Influenza activity update a transcript of the 20112012 influenza season update telebriefing held on friday, february 23, 2012 at 1pm et. Influenzavirus a a genus of viruses containing the agent of influenza a.
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