The history of flu viruses teaches that the influence has origin. Spread of canine influenza ah3n2 virus, united states. Influenza a viruses were predominant in most countries and accounted for 59% of all influenza viruses detected. In addition we also examined their effects on the influenza neuraminidase and hemagglutinin, the major viral antigens. A newly recognized livestock influenza virus, originally thought to be an influenza c virus, might represent a fourth genus, influenza d. Birds, pigs, horses, ferrets, dogs, and cats can all be infected with various strains of the influenza virus. Manual for the laboratory diagnosis and virological. Flu is a contagious disease that spreads around the united states every year, usually between october and may.
Type a influenza infection can be serious and cause widespread outbreaks and disease. Influenza a viruses can also cause sporadic infections or spread worldwide. There is an ongoing pandemic with a new coronavirus. Questions and answers immunization action coalition. Globally, cocirculation of both ah1n1pdm09 and ah3n2 viruses was evident in most reporting countries, areas and territories.
Virus influenza bersirkulasi di setiap bagian dunia. Influenza a virus subtype h1n1 ah1n1 is the subtype of influenza a virus that was the most common cause of human influenza flu in 2009, and is associated with the 1918 outbreak known as the spanish flu. The influenza virus is part of a family of rna viruses known as the orthomyxoviridae, and there are three different types of this virus known as a, b and c. Subtypes of the type a influenza virus are identified by two antigens influenza virus proteins called hemagglu. A canine influenza ah3n2 virus emerged in the united states in februarymarch 2015, causing respiratory disease in dogs.
Influenza in birds is often referred to as avian influenza, in pigs as swine influenza, in horses as equine influenza and so on. Seasonal influenza seasonal influenza viruses circulate and cause disease in humans every year. For this reason, they are described as h1n1, h1n2 etc. In the spring of 2009, a novel influenza a h1n1 virus emerged. Influenza, known as the flu, is a highly contagious respiratory virus. Structure of influenza virion influenza virions fig. The 1968 pandemic was caused by an influenza a h3n2 virus comprised of two genes from an avian influenza a virus, including a new h3 hemagglutinin, but also contained the n2 neuraminidase from the 1957 h2n2 virus. Influenza virus fact sheet morgridge institute for research. This work is licensed under a creative commons attribution. The influenza a virus is unique among the viruses because it is frequently subject virus to antigenic variation, both major and minor.
July 20 this document is provided in order to clarify the differences among seasonal influenza, pandemic influenza, and zoonotic or variant influenza. It was first noted in the united states in september 1968. Influenza viruses cause acute respiratory inflammation in humans and symptoms such as high fever, body aches, and fatigue. The influenza virus vaccine code set is updated on a quarterly basis. Cr11603 provides instructions for payment and edits for medicares common working file cwf and the fiscal intermediary shared system fiss to include and update new or existing influenza virus vaccine codes. Treating the host response to emerging virus diseases. Influenza disease alabama department of public health. The united states is not currently experiencing an influenza pandemic. Influenza in humans is often referred to as the seasonal flu. Influenza a virus, influenza b virus, and influenza c virus, respectively table 10. The world health organization who declared the virus a global pandemic.
The genome of influenza viruses is a linear, segmented and formed by ssrna. The virus was first recognized in april 2009 and spread quickly to 74 countries worldwide. Influenza also known as the flu is a contagious viral infection that attacks your respiratory system. It typically spreads through respiratory droplets when a person. This will ensure that the risk assessment is informed by the latest and most comprehensive information available about the virus, the extent of its circulation in animals and the number and severity of human infections. The influenza type a virus, known as h1n1 is a respiratory infection that was popularly named swine flu. Influenza viruses infect many vertebrates, with influenza a, b and c viruses iav, ibv, and icv infecting humans. Antigenic shift the appearance in the human population of an influenza a virus containing a novel ha protein with or without a novel na protein that are immunologically different from those of isolates circulating previously.
Influenza is an acute respiratory illness, caused by influenza a, b, and c viruses, that occurs in local outbreaks or seasonal epidemics. When there is a sudden, complete or major change, it is called a shift, and when the antigenic change is gradual, over a period of time, it is called a drift 8152016 11hemant kumar. Influenza viruses are orthomyxoviruses that cause acute. Influenza diagnosis clinical and epidemiological characteristics increase of febrile respiratory illness lab isolation of influenza virus from clinical specimen e. Pdf antiviral activity of garlic extract on influenza virus. Ending april 4, 2020 influenza vaccine composition 20192020. Influenza, also called the flu, is a viral disease that affects humans and many animals. People of all ages can get the flu, from babies and young adults, to the elderly.
The influenza virus is responsible for the respiratory illness known as influenza or flu which infects cells within the nose, throat and lungs. Semua tiga jenis virus influenza membuat keluarga mereka sendiri di pohon kekerabatan disebut orthomyxoviridae. Kasus flu akibat virus tipe c terjadi lebih jarang dari a dan b. It was detected first in the united states and spread quickly across the united states and the world. 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. Influenza a viruses are classified by subtypes based on the properties. This new h1n1 virus contained a unique combination of influenza genes not previously identified in animals or people. Influenza viruses that infect humans can be classified into three main groups. Infants and young children, people 65 years of age and older, pregnant women, and people with certain health conditions or. The latter are composed of key genes from the 1918 virus, updated by subsequentlyincorporated avian influenza genes that code for novel surface proteins, making the 1918 virus indeed the mother of all pandemics. Human influenza a and b viruses cause seasonal epidemics of disease known as the flu season almost every winter in the united states.
Influenza virus h1n1 fact sheet morgridge institute for. Influenza b virus is a main causative pathogen of annual influenza epidemics, however, research on influenza b virus in general lags behind that on influenza a viruses, one of the important reasons is studies. Influenza the center for food security and public health iowa. It most commonly causes a fever and respiratory problems. Mehrbod and others published antiviral activity of garlic extract on influenza virus find, read and cite all the research you need on researchgate. These viruses contain two highly variable surface antigens, the. Clinical illness follows a short incubation period and presentation ranges from asymptomatic to fulminant, depending on the characteristics of both the virus and the individual host. Quarterly influenza virus vaccine code update july 2020. Influenza response planning for the centers of excellence for influenza research and surveillance. Type a influenza is a contagious viral infection that can have lifethreatening complications if left untreated. Influenza mostly referred to as flu is a contagious viral infection caused primarily by the influenza virus a or b. Pdf rescue of influenza a virus from recombinant dna. Virus and disease, epidemics and pandemics steinhoff.
Humans can also be infected with influenza viruses that are routinely circulating in animal s, such as avian influenza virus subtypes ah5n1 and ah9n2 and swine influenza virus subtypes ah1n1 and h3n2. Di antara banyak subtipe virus influenza a, saat ini subtipe influenza a h1n1 dan a h3n2 adalah yang banyak beredar di antara manusia. Science preparedness for enhancing global health security kristine a. Influenza a viruses are the only influenza viruses known to cause flu pandemics, i. Influenza adalah virus yang terbungkus, yang berarti mendapatkan lipid bilayer dari membran plasma sel inang. North america, where swine influenza viruses have become very diverse. Influenza pneumonia incidence was high in 2005, a year when influenza ah3n2 subtype virus strains predominated, low in 2006 when ah1n1 viruses were more. Structure of influenza viruses, connected with influenza.
When a foreign ha andor na ends up in a virus with human segments. The tree shrew is a promising model for the study of influenza b virus infection. While influenza a viruses infect humans and other animals, influenza b viruses affects only humans, primarily children. Anyone can get the flu, but it is more dangerous for some people. Influenza ah3n2 viruses circulated in higher proportions than ah1n1pdm09 viruses in. Flu goes around every year, with some years being worse than others. The virus had previously been circulating among dogs in asia, where it originated through the transfer of an avianorigin influenza virus around 2005 and continues to circulate. This virus was designated as influenza a h1n1pdm09 virus. Influenza y pandemias textbook of influenza edited by robert g. Division of public health respiratory virus surveillance report week 14. Recommended composition of influenza virus vaccines for. Influenza a symptoms can be confused with signs of.
Antigenic shift is responsible for worldwide pandemics. Itulah sebabnya hanya virus influenza a dan b termasuk dalam vaksin influenza musiman. It can cause mild to severe illness, hospitalization, and even death. In both experimental and human influenza, a greater degree of virus replication is generally associated with greater inflammation and.
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