Influenza

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Influenza, 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

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Shifting blame is socially contagious

Other Sciences / Social Sciences

created Nov 19, 2009 | popularity 4.6 / 5 (9) | comments 3

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 ...


New research helps explain why bird flu has not caused a pandemic

New research helps explain why bird flu has not caused a pandemic

Medicine & Health / Diseases

created Nov 19, 2009 | popularity 5 / 5 (5) | comments 1

(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

created Nov 24, 2009 | popularity 3.3 / 5 (7) | comments 4

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.


'Emotions increase or decrease pain': researchers

Medicine & Health / Research

created Nov 10, 2009 | popularity 5 / 5 (3) | comments 0

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 (AP)

Vaccines on horizon for AIDS, Alzheimer's, herpes

Medicine & Health / Medications

created Nov 17, 2009 | popularity 3.8 / 5 (4) | comments 1

(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 ...


Scientists begin to unravel what makes pandemic H1N1 tick

Medicine & Health / Diseases

created Nov 16, 2009 | popularity 5 / 5 (2) | comments 0

As the number of deaths related to the pandemic H1N1 virus, commonly known as "swine flu," continues to rise, researchers have been scrambling to decipher its inner workings and explain why the incidence is lower than expected ...


Mutation found in swine flu virus: WHO

Medicine & Health / Diseases

created Nov 20, 2009 | popularity 3.3 / 5 (3) | comments 0

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 put interactive flu tracking at public's fingertips

Scientists put interactive flu tracking at public's fingertips

Medicine & Health / Diseases

created Nov 16, 2009 | popularity 2 / 5 (4) | comments 1

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 ...


Syringes with influenza virus vaccine sitting on a tray

Google launches online flu shot finder

Technology / Internet

created Nov 11, 2009 | popularity 3.5 / 5 (2) | comments 0

Google on Tuesday launched an online tool for tracking down where to get vaccinations against H1N1 and seasonal influenza in the United States.


Hajj devil stoning ritual biggest swine flu risk (AP)

Hajj devil stoning ritual biggest swine flu risk

Medicine & Health / Diseases

created Nov 28, 2009 | popularity 3 / 5 (2) | comments 1

(AP) -- Millions of Muslim pilgrims, many wearing surgical masks, jostled together shoulder-to-shoulder furiously casting pebbles at stone walls representing the devil Saturday - the hajj ritual of highest ...


pig

Researchers sequence swine genome

Biology / Biotechnology

created Nov 02, 2009 | popularity 5 / 5 (1) | comments 0

(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.


Commercial pigs in Ind. test positive for H1N1

Medicine & Health / Diseases

created Nov 04, 2009 | popularity 5 / 5 (1) | comments 1

(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.


Island village hit by suspected swine flu (AP)

Island village hit by suspected swine flu

Medicine & Health / Diseases

created Nov 07, 2009 | popularity 5 / 5 (1) | comments 2

(AP) -- Suspected swine flu is sweeping a traditional Eskimo whaling village on a remote Alaska island - prompting an urgent medical mission to deliver help.


Amid the flu epidemic, don't forget RSV in young children

Medicine & Health / Diseases

created Nov 23, 2009 | popularity 5 / 5 (1) | comments 0

Influenza, particularly H1N1, has understandably captured the attention of public health officials, the media and the public. However, an analysis from Children's Hospital Boston, based on patients seen in its emergency department ...


Scientists find previous seasonal flu infections may provide some level of H1N1 immunity

Medicine & Health / Diseases

created Nov 16, 2009 | popularity 4 / 5 (1) | comments 0

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.