Nov 22, 2016 historical perspective emergence of influenza a h1n1 viruses. Its called swine flu because in the past, the people who caught it had direct contact with pigs. Influensa ah1n1pdm09 virus er i denne rapporten benevnt som ah1n1 eller ah1. The influenza virus leads to respiratory disease that. Influenza is a wellknown viral infectious disease that occurs almost every year epidemically, becoming occasionally pandemic. Aug, 2009 in the 4 months since it was first recognized, the pandemic strain of a novel influenza a h1n1 virus has spread to all continents and, after documentation of humantohuman transmission of the virus in at least three countries in two separate world health organization who regions, the pandemic alert was raised to level 6. Key information about swine influenza viral subtypes in north america includes the following. That changed several years ago, when a new virus emerged that. By country, the proportion of orvs ranged from 0% to 68%, with the highest proportion in norway. Apr 27, 2009 case definitions for infection with swine influenza a h1n1 virus. The membrane contains two types of surface proteins and a number of protein channels. Influenza activity was reduced in australia and was below the seasonal threshold in new zealand throughout this period. H1n1 flu can be spread to humans from contact with infected pigs.
The aim of this study is to provide an overview of the. Its thought that novel influenza a h1n1 flu spreads in the same way that regular seasonal influenza viruses spread, mainly through the coughs and sneezes of people who are sick with the virus, but it may also be spread by touching infected objects and then touching your nose or mouth. The pandemics include 1918 spanish flu ah1n1 3, 1957 ah2n2 asia. Influenza a h1n1 2009 is a universal pandemic that is affecting most of the countries in the. Worlds best powerpoint templates crystalgraphics offers more powerpoint templates than anyone else in the world, with over 4 million to choose from. The typical swine influenza swine flu is an acute viral infection of the respiratory tract in pigs, caused by type a influenza virus. In the english and dutchspeaking caribbean, pandemic influenza a h1n1 was the predominantcirculatinginfluenzavirustypeduringthepandemicperiod. At first all individuals seeking consultations for flu like symptoms should be screened at.
Influenza virus characterisation summary europe, july 2019. Pdf novel influenza ah1n1 virus among gravid admissions. Influenza a viruses were predominant in most countries and accounted for 59% of all. Mean viral loads for patients with pandemic h1n1 2009 were. Pdf pandemic novel influenza ah1n1 is a substantial threat and cause of morbidity and mortality in the pregnant population. The strain was referred to as swine flu as it has strong similarities with current circulating swine influenza viruses, although the first outbreak on a swine farm was recorded more than 2 mo following the first human reports.
Ethnicity, deprivation and mortality due to 2009 pandemic influenza ah1n1 in england during the 20092010 pandemic and the first postpandemic season volume 143 issue 16 h. The virus involved in the spring 2009 global influenza outbreak is a new strain of influenza virus affecting humans. Surveillance of influenza like illness severe acute respiratory infection is being done. Centers for disease control and prevention key facts about swine influenza swine flu retrieved on april 30, 2009. It is an orthomyxovirus that contains the glycoproteins haemagglutinin and neuraminidase. 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. Comparison of pandemic h1n1 2009 and seasonal influenza. Water birds harbor the widest diversity of flu strains, however the symptoms of the disease are usually not detectable in them 1.
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 spanish flu outbreak. Sample has been sent to ncdc, new delhi for lab confirmation. Transmission of swine flu virus from pigs to humans is uncommon and does not always cause human influenza, often. Oseltamivirresistant influenza viruses a h1n1 orvs with h275y mutation in the neuraminidase emerged independently of drug use. Influenzavirus a subtipo h1n1 wikipedia, a enciclopedia livre. Swine influenza is considered endemic in swine in the united states, and animal outbreaks occur with regular frequency usually in the fall and winter months.
Swine flu, novel influenza ah1n1 virus swine flu refers to disease caused by strains of influenza virus that usually infect pigs 1. A confirmed case of novel influenza a h1n1 virus infection is defined as a person with an influenza like illness with laboratory confirmed novel influenza a h1n1 virus infection by one or more of the following tests. Before infecting humans individual influenza strains usually spread among cattle and fowl 2. Ah3n2 less prevalent than ah1n1pdm09 viruses and byamagata more. Oseltamivirresistant influenza virus a h1n1, europe. Although referred to as swine influenza in many reports, scientific evidence shows that it is different from the swine influenza virus affecting pigs. One suspected patient is admitted in isolation ward in rims, ranchi. Jul 19, 2010 the current influenza a h1n1 2009 strain is a result of genetic translocation from three different species. Unicef dominican republic salud influenza o gripe a h1n1. Recommended composition of influenza virus vaccines for. The mortality rate is low in pigs and recovery usually occurs within 710 days. Influenza viruses infect humans, several other mammals and birds. What is the difference between the new influenza ah1n1 and swine influenza.
Rules of cooccurring mutations characterize the antigenic evolution. The virus is infecting people and is spreading from persontoperson. April, the causative virus was confirmed as being influenza a h1n1 of swine origin. In order to prevent and contain outbreak of influenza a h1n1 virus for screening, testing and isolation following guidelines are to be followed.
Neither pandemic nor seasonal influenza viral loads correlated with clinical severity of illness. Definition virus subtype of influenza, clinically identified in april 2009, affecting humans, which contains genes from pig, bird and human influenza viruses, in a combination that had never been observed before anywhere in the world. The networks of site mutations in the ha1 protein of influenza b, ah1n1 and a h3n2 viruses are shown in additional file 1. Avian influenza a viruses are designated as highly pathogenic avian influenza hpai or low pathogenicity avian influenza lpai based on molecular characteristics of the virus and the ability of the virus to cause disease and mortality in chickens in a laboratory setting. Travelrelated influenza ah1n1 infection at a rock festival in.
The viruss shape is determined by a layer of matrix protein underneath the influenza membrane. Influenza ah1n1 is a respiratory illness, and the symptoms are similar to those of the regular human seasonal flu. Few young people had any existing immunity as detected by antibody response to the h1n1pdm09 virus, but nearly onethird of people over 60 years old had antibodies against this virus, likely from exposure to an older h1n1 virus earlier in their lives. In the spring of 2009, a new human influenza a h1n1 virus emerged in mexico and the united states. The 2009 outbreak is due to a new subtype of the type a strain, called h1n1. Historical perspective emergence of influenza a h1n1 viruses. Winner of the standing ovation award for best powerpoint templates from presentations magazine.
Because this virus is very different from current seasonal influenza viruses, many people will not have protective immunity against it and the seasonal flu vaccine will not protect against it either. H1n1 influenza a virus was first isolated from pigs in the united states in 1930. Influenza is an acute respiratory illness, caused by influenza a, b, and c viruses, that occurs in local outbreaks or seasonal epidemics. The h1n1pdm09 virus was very different from h1n1 viruses that were circulating at the time of the pandemic. Novel influenza ah1n1 swine flu sri lanka journal of child health, 2009. Novel influenza a h1n1 is caused by a new flu virus that was first detected in april, 2009. Implementation of the international health regulations 2005. Swine influenza a h1n1 infection in two childrensouthern california, march april. In the splitdalmatia county sdc, the first influenza case caused by an infection with the pandemic influenza a virus h1n12009 was reported on 3 july, 2009. Highly pathogenic and low pathogenic avian influenza a viruses. Ethnicity, deprivation and mortality due to 2009 pandemic.
Travelrelated influenza ah1n1 infection at a rock festival in hungary. Africa there was cocirculation of influenza a and b viruses with ah3n2 viruses predominating. Influenza situation report pan american health organization. Theyll give your presentations a professional, memorable appearance the kind of sophisticated look that todays audiences expect. Influenza is a major cause of global morbidity and mortality each year, especially among older adults and those with chronic diseases. 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. Information from its description page there is shown below. Influenza ah1n1pdm09 virus ph1n1 was the causal factor of the recent flu pandemic, which claimed several hundred lives. This file is licensed under the creative commons attributionshare alike 3. Mortality burden from seasonal influenza and 2009 h1n1.
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