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 flu
Does the H1N1 vaccine contain mercury?
Sep 15, 2009 |
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In the words of President Obama "don't be alarmed, be prepared" for the swine flu (or, officially, the H1N1 virus). But what if the preparation is more alarming than the flu?
Shifting blame is socially contagious
Other Sciences / Social Sciences
Nov 19, 2009 |
4.6 / 5 (9) |
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Merely observing someone publicly blame an individual in an organization for a problem - even when the target is innocent - greatly increases the odds that the practice of blaming others will spread with the tenacity of the ...
Man-made crises 'outrunning our ability to deal with them,' scientists warn
Sep 11, 2009 |
2.6 / 5 (14) |
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The world faces a compounding series of crises driven by human activity, which existing governments and institutions are increasingly powerless to cope with, a group of eminent environmental scientists and economists has ...
Gene Hijacked By HIV Ancestor Suggests New Way to Block Viral Reproduction
Dec 07, 2009 |
4.9 / 5 (7) |
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(PhysOrg.com) -- An ancestor of the AIDS virus hijacked an entire gene, perhaps from some prehistoric cat it had infected, a gene that makes it much better able to infect humans, according to a study published ...
Scientists discover influenza's Achilles heel: Antioxidants
Oct 29, 2009 |
4.3 / 5 (7) |
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As the nation copes with a shortage of vaccines for H1N1 influenza, a team of Alabama researchers have raised hopes that they have found an Achilles' heel for all strains of the flu—antioxidants. In an article appearing in ...
New research helps explain why bird flu has not caused a pandemic
Nov 19, 2009 |
5 / 5 (5) |
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(PhysOrg.com) -- Bird flu viruses would have to make at least two simultaneous genetic mutations before they could be transmitted readily from human to human, according to research published today in PLoS ON ...
Six bad reactions to swine flu vaccine in Canada: official (Update)
Medicine & Health / Medications
Nov 24, 2009 |
3.3 / 5 (7) |
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Six severe allergic reactions to swine flu vaccinations have been observed in Canada, health authorities said Tuesday, adding that all of the individuals are feeling better.
Most would refuse emergency use H1N1 vaccine or additive
Sep 29, 2009 |
4.8 / 5 (4) |
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A majority of Americans would not take an H1N1 flu vaccine or drug additive authorized for emergency use by the Food and Drug Administration, according to a University of Pittsburgh Graduate School of Public Health and University ...
HIV's ancestors 'plagued first mammals'
Other Sciences / Archaeology & Fossils
Sep 18, 2009 |
4.5 / 5 (4) |
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(PhysOrg.com) -- The retroviruses which gave rise to HIV have been battling it out with mammal immune systems since mammals first evolved around 100 million years ago - about 85 million years earlier than ...
Swine flu shot: Intense tracking for side effects
Sep 27, 2009 |
4.3 / 5 (4) |
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(AP) -- More than 3,000 people a day have a heart attack. If you're one of them the day after your swine flu shot, will you worry the vaccine was to blame and not the more likely culprit, all those burgers and fries?
Researcher shows possible link between 1918 El Nino and flu pandemic
Space & Earth / Earth Sciences
Sep 14, 2009 |
3.8 / 5 (4) |
1
Research conducted at Texas A&M University casts doubts on the notion that El Niño has been getting stronger because of global warming and raises interesting questions about the relationship between El Niño and a severe flu ...
'Emotions increase or decrease pain': researchers
Nov 10, 2009 |
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Getting a flu shot this fall? Canadians scientists have found that focusing on a pretty image could alleviate the sting of that vaccine. According to a new Université de Montréal study, published in the latest ...
Vaccines on horizon for AIDS, Alzheimer's, herpes
Medicine & Health / Medications
Nov 17, 2009 |
3.8 / 5 (4) |
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(AP) -- Malaria. Tuberculosis. Alzheimer's disease. AIDS. Pandemic flu. Genital herpes. Urinary tract infections. Grass allergies. Traveler's diarrhea. You name it, the pharmaceutical industry is working ...
Tamiflu Metabolite Found in Sewage Discharge, River Water
Oct 01, 2009 |
4.3 / 5 (3) |
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(PhysOrg.com) -- In a study published September 28th ahead of print in the peer-reviewed journal Environmental Health Perspectives, researchers measured oseltamivir carboxylate (OC), the active metabolite of the popular anti-i ...
WHO: nearly 5,000 swine flu deaths worldwide
Oct 23, 2009 |
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(AP) -- Nearly 5,000 people have reportedly died from swine flu since it emerged this year and developed into a global epidemic, the World Health Organization said Friday.
