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.
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.
Taming the flu: Researchers create map of interactions between flu virus and its human host
Dec 18, 2009 |
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(PhysOrg.com) -- There is no lack of worry this season over the flu, both the seasonal and H1N1 varieties, but there is a critical lack of understanding of the viruses that cause these illnesses. For years, ...
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.
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 ...
One dose of H1N1 vaccine may provide sufficient protection for infants and children
Dec 21, 2009 |
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One dose of vaccine may be effective to protect infants and children and reduce transmission of the H1N1 virus, according to a study in JAMA, published online today because of its public health implications. The study will a ...
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.
First immunological clue to why some H1N1 patients get very ill or die
Dec 15, 2009 |
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An international team of Canadian and Spanish scientists have found the first potential immunological clue of why some people develop severe pneumonia when infected by the pandemic H1N1 virus.
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 ...
CDC: Fewer states seeing widespread swine flu
Dec 11, 2009 |
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(AP) -- Health officials say winter flu is just starting to show up in the U.S. while swine flu infections continue to wane.
Severity of H1N1 flu in US during current flu season may be less than feared
Dec 08, 2009 |
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A new study from researchers at the UK Medical Research Council and the Harvard School of Public Health (HSPH) projects that the severity of the H1N1 flu during the autumn-winter flu season in the U.S. will likely be less ...
New York autopsies show 2009 H1N1 influenza virus damages entire airway
Dec 07, 2009 |
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In fatal cases of 2009 H1N1 influenza, the virus can damage cells throughout the respiratory airway, much like the viruses that caused the 1918 and 1957 influenza pandemics, report researchers from the National Institutes ...
Study links real-time data to flu vaccine strategies
Dec 03, 2009 |
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Adaptive vaccination strategies, based on age patterns of hospitalizations and deaths monitored in real-time during the early stages of a pandemic, outperform seasonal influenza vaccination allocation strategies, according ...
