Related topics: swine flu , virus , flu , vaccine , pandemic
Influenza
hideInfluenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae (the influenza viruses), that affects birds and mammals. The name influenza comes from the Italian influenza, meaning "influence" (Latin: influentia). The most common symptoms of the disease are chills, fever, sore throat, muscle pains, severe headache, coughing, weakness and general discomfort. Fever and coughs are the most frequent symptoms. In more serious cases, influenza causes pneumonia, which can be fatal, particularly for the young and the elderly. Although it is often confused with other influenza-like illnesses, especially the common cold, influenza is a much more severe disease than the common cold and is caused by a different type of virus. Influenza may produce nausea and vomiting, particularly in children, but these symptoms are more common in the unrelated gastroenteritis, which is sometimes called "stomach flu" or "24-hour flu".
Typically, influenza is transmitted through the air by coughs or sneezes, creating aerosols containing the virus. Influenza can also be transmitted by bird droppings, saliva, nasal secretions, feces and blood. Infection can also occur through contact with these body fluids or through contact with contaminated surfaces. Airborne aerosols have been thought to cause most infections, although which means of transmission is most important is not absolutely clear. Influenza viruses can be inactivated by sunlight, disinfectants and detergents. As the virus can be inactivated by soap, frequent hand washing reduces the risk of infection.
Influenza spreads around the world in seasonal epidemics, resulting in the deaths of hundreds of thousands annually — millions in pandemic years. Three influenza pandemics occurred in the 20th century and killed tens of millions of people, with each of these pandemics being caused by the appearance of a new strain of the virus in humans. Often, these new strains appear when an existing flu virus spreads to humans from other animal species, or when an existing human strain picks up new genes from a virus that usually infects birds or pigs. An avian strain named H5N1 raised the concern of a new influenza pandemic, after it emerged in Asia in the 1990s, but it has not evolved to a form that spreads easily between people. In April 2009 a novel flu strain evolved that combined genes from human, pig, and bird flu, initially dubbed "swine flu", emerged in Mexico, the United States, and several other nations. WHO officially declared the outbreak to be a "pandemic" on June 11, 2009.
Vaccinations against influenza are usually given to people in developed countries and to farmed poultry. The most common human vaccine is the trivalent influenza vaccine (TIV) that contains purified and inactivated material from three viral strains. Typically, this vaccine includes material from two influenza A virus subtypes and one influenza B virus strain. The TIV carries no risk of transmitting the disease, and it has very low reactivity. A vaccine formulated for one year may be ineffective in the following year, since the influenza virus evolves rapidly, and new strains quickly replace the older ones. Antiviral drugs can be used to treat influenza, with neuraminidase inhibitors being particularly effective.
For more information about Influenza, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with influenza
Researchers find human protein that prevents H1N1 influenza infection
Dec 17, 2009 |
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Howard Hughes Medical Institute researchers have identified a naturally occurring human protein that helps prevent infection by H1N1 influenza and other viruses, including West Nile and dengue virus.
Study reveals H1N1 unexpected weakness
Dec 10, 2009 |
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The H1N1 influenza virus has been keeping a secret that may be the key to defeating it and other flu viruses as well.
Scientists develope optimal flu vaccine priorities, question federal guidelines
Aug 20, 2009 |
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(PhysOrg.com) -- Optimal control of the spread of the seasonal flu and H1N1 is achieved by prioritizing vaccinations for schoolchildren and for adults aged 30 to 39 in the United States. Those are the findings of a new study ...
Study: H1N1 flu virus ill-suited for rapid transmission, but new strain bears watching, could mutate
Jul 02, 2009 |
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A team from MIT and the Centers for Disease Control and Prevention has found a genetic explanation for why the new H1N1 "swine flu" virus has spread from person to person less effectively than other flu viruses.
Scientists learn why the flu may turn deadly
May 04, 2009 |
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As the swine flu continues its global spread, researchers from the Children's Hospital of Philadelphia, Pennsylvania, have discovered important clues about why influenza is more severe in some people than it is in others. ...
1918 flu resulted in current lineage of H1N1 swine influenza viruses, study says
Apr 30, 2009 |
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In 1918 a human influenza virus known as the Spanish flu spread through the central United States while a swine respiratory disease occurred concurrently. A Kansas State University researcher has found that the virus causing ...
Mexicans put faith in masks -- but do they work?
Apr 28, 2009 |
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(AP) -- The cloth patches in green, blue and white are everywhere, clamped tight over the mouth and nose of teachers, toddlers, policemen and drunks. Even the statue at the church of St. Jude, patron of lost ...
Scientist warns over pandemic flu vaccine 6-month time lag
Apr 27, 2009 |
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New research published today (Monday April 27) from the University of Leicester and University Hospitals of Leicester NHS Trust warns of a six-month time lag before effective vaccines can be manufactured in the event of a ...
H1N1 influenza adopted novel strategy to move from birds to humans
Dec 08, 2009 |
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(PhysOrg.com) -- The 2009 H1N1 influenza virus used a new strategy to cross from birds into humans, a warning that it has more than one trick up its sleeve to jump the species barrier and become virulent.
Knockouts in human cells point to pathogenic targets
Nov 26, 2009 |
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(PhysOrg.com) -- Whitehead researchers have developed a new approach for genetics in human cells and used this technique to identify specific genes and proteins required for pathogens.
Mutation found in swine flu virus: WHO
Nov 20, 2009 |
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The World Health Organisation said Friday that a mutation had been found in samples of the swine flu virus taken following the first two deaths from the pandemic in Norway.
Scientists find previous seasonal flu infections may provide some level of H1N1 immunity
Nov 16, 2009 |
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Researchers at the La Jolla Institute for Allergy & Immunology have found that previous influenza infections may provide at least some level of immunity to the H1N1 "swine" flu.
Scientists put interactive flu tracking at public's fingertips
Nov 16, 2009 |
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New methods of studying avian influenza strains and visually mapping their movement around the world will help scientists more quickly learn the behavior of the pandemic H1N1 flu virus, Ohio State University ...
Google launches online flu shot finder
Nov 11, 2009 |
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Google on Tuesday launched an online tool for tracking down where to get vaccinations against H1N1 and seasonal influenza in the United States.
Scientists Propose New Explanation for Flu Virus Antigenic Drift
Oct 29, 2009 |
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(PhysOrg.com) -- Influenza viruses evade infection-fighting antibodies by constantly changing the shape of their major surface protein. This shape-shifting, called antigenic drift, is why influenza vaccines ...
