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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
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.
Compound found to safely counter deadly bird flu
Dec 21, 2009 |
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The specter of a drug-resistant form of the deadly H5N1 avian influenza is a nightmare to keep public health officials awake at night.
Privacy concerns could limit benefits from real-time data analysis, researcher says
Technology / Computer Sciences
Dec 17, 2009 |
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Society will be unable to take full advantage of real-time data analysis technologies that might improve health, reduce traffic congestion and give scientists new insights into human behavior until it resolves questions about ...
Bacteria wouldn't opt for a swine flu shot
Dec 16, 2009 |
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Bacteria inhabited our planet for more than 4 billion years before humans showed up, and they'll probably outlive us by as many eons more. That suggests they may have something to teach us.
CDC: About 1 in 6 Americans have had swine flu (Update)
Dec 10, 2009 |
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(AP) -- Swine flu has sickened about 50 million Americans, and killed about 10,000, according to new estimates released by federal health officials on Thursday.
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.
Gene Hijacked By HIV Ancestor Suggests New Way to Block Viral Reproduction
Dec 07, 2009 |
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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 ...
Study: Swine flu poses a threat to new moms
Dec 23, 2009 |
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(AP) -- Swine flu is not only dangerous to pregnant women, but it's a threat to new mothers too, the first study to document this risk shows. An analysis of pregnant women and new mothers who were hospitalized with swine ...
How flu succeeds: Investigators identify host factors that help multiple influenza strains thrive
Dec 22, 2009 |
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Investigators at Burnham Institute for Medical Research (Burnham), Mount Sinai School of Medicine (Mount Sinai), the Salk Institute for Biological Studies (Salk) and the Genomics Institute of the Novartis Research Foundation ...
Global swine flu pandemic deaths pass 10,000: WHO
Dec 18, 2009 |
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The number of swine flu deaths worldwide passed the 10,000 mark about eight months after the pandemic strain was uncovered in April, reaching 10,582, World Health Organisation data showed Friday.
Santa should get off his sleigh and walk, says public health doctor
Dec 16, 2009 |
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Santa should share Rudolf's snack of carrots and celery sticks rather than brandy and mince pies and swap his reindeer for a bike or walk, says a public health expert in the Christmas issue published in BMJ today.
Netherlands to slaughter more animals in Q fever epidemic
Dec 16, 2009 |
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The Netherlands stepped up measures Wednesday against the world's biggest Q fever epidemic that has killed 10 humans, by ordering the slaughter of over 30,000 animals, a press release said.
Kids' Swine flu shots recalled; not strong enough
Medicine & Health / Medications
Dec 15, 2009 |
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(AP) -- Hundreds of thousands of swine flu shots for children have been recalled because tests indicate the vaccine doses lost some strength, government health officials said Tuesday.
Influenza in Africa should not be ignored
Dec 15, 2009 |
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Influenza is circulating in Africa, but virtually no information or attention is evident, says a new essay in this week's PLoS Medicine. Maria Yazdanbakhsh and Peter Kremsner argue that the lack of adequate surveillance means ...
Pandemic toolkit offers flu with a view
Technology / Computer Sciences
Dec 14, 2009 |
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(PhysOrg.com) -- As communities brace for rising wintertime influenza cases, scientists are developing a mathematical and visual analytic toolkit to help health officials quickly analyze pandemics and craft ...
