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
Island village hit by suspected swine flu
Nov 07, 2009 |
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(AP) -- Suspected swine flu is sweeping a traditional Eskimo whaling village on a remote Alaska island - prompting an urgent medical mission to deliver help.
In Europe, most swine flu shots by invitation only
Nov 06, 2009 |
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(AP) -- In Britain, there are no long lines of people seeking swine flu vaccine. Doctor's offices aren't swamped with desperate calls. And there are no cries of injustice that the vaccine is going to wealthy ...
K-State Expert Says Fear Of H1N1 Amplifies Normal Anxiety About School, Offers Tips On How To Cope
Medicine & Health / Psychology & Psychiatry
Nov 06, 2009 |
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For university students, anxiety about grades is nothing new. But this year, students also may be anxious about the H1N1 flu virus and missing classes.
Poll: Many parents, high-priority adults who tried to get H1N1 vaccine unable to get it
Nov 06, 2009 |
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(PhysOrg.com) -- A new national poll from Harvard School of Public Health (HSPH) researchers found that a majority of adults who tried to get the H1N1 vaccine for themselves or their children have been unable ...
Goldman Sachs, Citigroup got swine flu vaccine
Medicine & Health / Medications
Nov 05, 2009 |
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(AP) -- Some of New York's biggest companies, including Wall Street giants Goldman Sachs and Citigroup, received doses of swine flu vaccine for at-risk employees, drawing criticism that the hard-to-find vaccine ...
WHO: Swine flu virus is top strain worldwide
Nov 05, 2009 |
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(AP) -- The World Health Organization's flu chief said the swine flu virus has now become the predominant flu strain worldwide.
Scientists track swine flu virus for tiny changes that would cause big problems
Nov 04, 2009 |
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As the H1N1 flu virus spreads at breakneck speed, a team of scientists are close behind. They are watching its evolution through a cutting-edge technology in hopes of answering the question: Where did it come from -- and ...
Commercial pigs in Ind. test positive for H1N1
Nov 04, 2009 |
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(AP) -- The U.S. Department of Agriculture said Wednesday that pigs in a commercial herd in Indiana have tested positive for swine flu, making it the first time the virus has been found in such hogs.
When should flu trigger a school shutdown?
Nov 04, 2009 |
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As flu season approaches, parents around the country are starting to face school closures. But how bad should an influenza outbreak be for a school to shut down? A study led by epidemiologists John Brownstein, PhD, and Anne ...
Officials: Swine flu confirmed in Iowa cat
Nov 04, 2009 |
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(AP) -- The swine flu virus has been confirmed in a cat treated at the Iowa State University College of Veterinary Medicine.
Common Pain Relievers May Dilute Power of Flu Shots
Medicine & Health / Medications
Nov 03, 2009 |
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(PhysOrg.com) -- With flu vaccination season in full swing, research from the University of Rochester Medical Center cautions that use of many common pain killers - Advil, Tylenol, aspirin - at the time of injection may blunt ...
Initial results show pregnant women mount strong immune response to one dose of 2009 H1N1 vaccine
Medicine & Health / Medications
Nov 02, 2009 |
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Healthy pregnant women mount a robust immune response following just one dose of 2009 H1N1 influenza vaccine, according to initial results from an ongoing clinical trial sponsored by the National Institute of Allergy and ...
Sneezing in times of a flu pandemic
Medicine & Health / Psychology & Psychiatry
Nov 02, 2009 |
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The swine flu (H1N1) pandemic has received extensive media coverage this year. The World Health Organization, in addition to providing frequent updates about cases of infection and death tolls, recommends hyper vigilance ...
Researchers sequence swine genome
Nov 02, 2009 |
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(PhysOrg.com) -- A global collaborative has produced a first draft of the genome of a domesticated pig, an achievement that will lead to insights in agriculture, medicine, conservation and evolution.
New group helps US monitor swine flu shot safety
Nov 02, 2009 |
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(AP) -- Independent health advisers begin monitoring safety of the swine flu vaccine on Monday, an extra step the government promised in this year's unprecedented program to watch for possible side effects.
