Swine flu swine influenza is a respiratory disease caused by viruses influenza viruses belonging to. First human infection with new influenza a h1n1 virus detected in california. In preparing for influenza pandemics, public health agencies stockpile critical medical resources. Further evidence of occupational swine influenza virus infections was observed. In 2009, a new h1n1 influenza virus emerged, causing the first global flu pandemic in 40 years. This 1976 photograph shows a woman receiving a vaccination during the nationwide swine flu vaccination campaign. The 2009 swine h1n1 flu pandemic responsible for more than 17,000 deaths worldwide originated in pigs from a very small region in central mexico, a. The virus is spread among pigs by aerosols and direct and indirect contact, and. Swine flu is the name for the influenza type a virus that affects pigs swine. Swine influenza the center for food security and public health. However, localized outbreaks of various magnitudes are likely to continue. Origins of the 2009 h1n1 influenza pandemic in swine in mexico. Influenza a viruses are constantly changing, making it possible on very rare occasions for nonhuman influenza viruses to change in such a way that they can infect people easily and spread efficiently from person to person.
Swine flu h1n1, h3n2v symptoms, vaccination, treatment. A study of the swine flu h1n1 epidemic among health care. Although swine flu doesnt typically affect humans, there was a global outbreak in 2009 to 2010the first flu pandemic in more than 40 years. Jan, shakilurehman swine flu, also called hog or pig flu, is an infection caused by any one of the several types of swine influenza virus siv which is common throughout pig population worldwide. Swine influenza virus siv or swine origin influenza virus soiv is any strain of the influenza family of viruses that is endemic in pigs.
Six of the genes are closest in sequence to those of h1n2 triplereassortant influenza viruses isolated from pigs in north america around 19992000. More than 200 soldiers were infected, including one who died from a bout of pneumonia caused by the. None of these viral descendants, however, approaches the pathogenicity of the 1918 parent virus. In humans, the severity of swine influenza can vary from mild to severe. Swine influenza frequently asked questions what is swine influenza. Scientists are still arguing about what the virus should be called, but most people know it as the h1n1. In the spring of 1976, it looked like that years flu was the real thing. The story of the great influenza pandemic of 1918 and. This type of influenza virus can also infect humans and birds. What is the history of h1n1 influenza swine flu pandemics. Swine influenza is an infection caused by any one of several types of swine influenza viruses. Department of history recorded only 54 flu related deaths.
Swine influenza virus is sometimes called siv or swine flu swine flu is common in pigs. Although there is not universal consensus regarding where the virus originated, it spread worldwide during 19181919. It originated in pigs but is spread primarily from person. Swine flu, both h1n1 and h3n2v, cause a respiratory infection. Swine flu, also called hog or pig flu, is an infection. Read about swine flu history, including the dreaded 1918 flu the health workers hope is not repeated. Apparently, the porcine h1n1 and h3n2 lineages uncommonly infect humans, and the human h1n1 and h3n2 lin.
From where did the 2009 swineorigin influenza a virus. Most commonly, these cases occur in persons with direct exposure to pigs e. Pigs experimentally infected with pandemic 2009 h1n1. The swineorigin influenza a h1n1 virus that appeared in 2009 and was first found in human beings in mexico, is a reassortant with at least three parents. Swine flu viruses cause high levels of illness and low death rates in pigs. The long shadow of the 1976 swine flu vaccine fiasco. Reporting requirements initial spread of the virus. Stockpiling ventilators for influenza pandemics volume. Very young children may not complain of fever or have. It was caused by an h1n1 virus with genes of avian origin. Swine flu is a highly contagious respiratory disease in pigs caused by one of several swine influenza a viruses see the image below.
It was caused by a thennew flu virus known as h1n1, an influenza virus thats a combination of swine, avian bird, and human genes that mixed together in pigs and spread. In the united states, it was first identified in military personnel in spring 1918. Swine influenza viruses may circulate among swine throughout the year, but most outbreaks occur. Its other two genes are from different eurasian avianlike viruses of pigs.
This disease is transmitted between the persons through coughing or sneezing with the virus. There is no evidence of this disease circulating in pigs in the uk and scientists are investigating its origins. Swine flu has been confirmed in a number of countries and it is spreading from human to human, which could. We introduce a method for optimizing stockpiles of mechanical ventilators, which are critical for treating hospitalized. The flu represented a little over one percent of the total deaths. Estimates of pandemic influenza mortality ranged from 0. Below is a timeline of major events that took place during the 2009 h1n1 pandemic.
The 2009 flu pandemic was the second h1n1 pandemic the world had seen the first being the 1918 spanish flu, still the most deadly pandemic in history. The reporting of swine flu cases in two california children this week stirred memories of the 1976 episode, which caused major embarrassment for public health. Historical perspective emergence of influenza a h1n1. Of the 189 possible causes of death listed, influenza ranked 20th. Though the 2009 flu pandemic primarily affected children and young and middleaged adults, the impact of the h1n1pdm09 virus on the global population during the first year was less severe than that of previous pandemics. Zhu h, webby r, lam tt, smith dk, peiris js, guan y. The outbreak of human infection due to the novel swineorigin influenza a h1n1 virus began in mexico in march 2009. Swine flu is a important communicable disease,with occurrence of epidemics and paramedics at frequent intervals bring the humans to risk of illness with morbidity and mortality, simple health related precautions reduce the gravity of the infections. Normally, it only infects people who have been in close contact with pigs. The h1n1 flu virus is estimated to have killed more than 4,000 in the united states and many more worldwide in the 20092010 flu season, causing the first global flu pandemic in over 40 years. While swine flu viruses normally do not infect humans, occasional infections of humans do occur.
It seemed to come out of nowhere, but our timeline explains how the origins of the h1n1 pandemic go back more than a century. Swine flu swine influenza is a respiratory disease caused by type a influenza. The outbreak was the third influenza pandemic to occur in the 20th century. Swine influenza simple english wikipedia, the free. The five leading causes of death in 1917 were premature births, heart disease, stillbirths, brights disease disease of the kidneys and pneumonia. Swine influenza was first proposed to be a disease related to human influenza. But theres a long history of safety and efficacy for flu vaccines made of h1n1 antigens, notes flu expert john treanor, md, chief. A new analysis of the current swineorigin h1n1 influenza. Pdf no abstract find, read and cite all the research you need on researchgate. The cdc recommends that swine influenza be considered in people who have fever and respiratory symptoms, especially cough or a sore throat. History of 1918 flu pandemic pandemic influenza flu cdc. Determining appropriate quantities and locations for such resources can be challenging, given the considerable uncertainty in the timing and severity of future pandemics.
Seasonal vaccine doesnt protect against the new swine flu bug. Serologic evidence of swine flu infection in humans was documented in 1958, 20 and the first isolation of swine influenza virus from a human occurred in 1974 from a patient with hodgkins disease. However, sporadic human infections with swine flu have occurred. Human cases of swine influenza a virus infection occur in individuals who have had a history of recent direct contact with pigs or close within 6 feet contact with pigs. Cidrap news swine influenza viruses have never been documented as the cause of a human influenza pandemic, but in 1976 they generated pandemic fears strong enough to trigger a nationwide vaccination campaign. Six months ago, swine flu emerged as a massive threat to global health. The 1968 flu pandemic resulted in an estimated one million to. The spanish flu pandemic of 1918, the deadliest in history, infected an estimated 500 million people worldwideabout onethird of the planets populationand killed an estimated 20 million. In 1976, a strain of the flu broke out on the army base at fort dix, n. Swine influenza virus is a virus that is common in pigs. The great swine flu epidemic of 1976 realclearpolitics. Pdf swine flu, also called hog or pig flu, is an infection caused by any one of the several types of swine influenza virus siv. While in the last few years, the world was contemplating if the avian influenza virus h5n1 would adapt for human spread, the recent outbreak of the swine origin. The coronavirus outbreak is more severe than the 2009 outbreak of h1n1, or swine flu.
Swine workers and swine influenza virus infections ncbi. Swine flu in humans centers for disease control and. H1n1 influenza or swine flu is a highly contagious acute respiratory disease of pigs caused by type a influenza virus that regularly causes outbreaks of influenza in pigs. Swine influenza swine flu is a respiratory disease of pigs caused by type a influenza virus that regularly causes outbreaks of influenza in pigs. A 3d medical animations illustrating how swine flu h1n1 influenza virus infects the respiratory system and attacks the healthy cells. The epidemic affected the course of history and was a terrifying presence at the end of world war i, killing more americans in a single year than died in battle in world war i. From 2005 until january 2009, 12 human cases of swine flu were reported. The disease in swine occurs within a herd either as an epizootic or enzootic form. Nausea, vomiting, or diarrhea has also occurred in people with swine flu. From the history of influenza epidemics and pandemics, which can be traced back with some accuracy for the past three hundred years, and with less.
It was believed that swine flu, a particularly deadly form of the virus, had a 60year mutation cycle that brought on worldwide pandemics, killing millions of people. Ill people may also have fatigue, chills, headache, or body aches. As of 2009, the known siv strains include influenza c and the subtypes of influenza a known as h1n1, h1n2, h2n1, h3n1, h3n2, and h2n3. Swine flu symptoms what is swine flu h1n1 influenza a. Swine influenza, or swine flu, is a highly contagious acute respiratory disease of pigs, caused by one of several swine influenza a viruses. Swine flu, respiratory tract infection, h1n1 virus, influenza virus. Later that april, both the world health organization and the obama administration declared a public health emergency. The 1918 influenza pandemic was the most severe pandemic in recent history. The virus is a reassortant a mix of genes from swine, bird, and human flu vir uses. A respiratory illness of pigs caused by infection with swine influenza a virus siv. Swine influenza aetiology epidemiology diagnosis prevention and control references swine influenza is a highly contagious viral infection of pigs.