Diseases, Conditions, Syndromes

Researchers bring us one step closer to universal influenza vaccine

The scourge of the influenza virus devastates health and claims many lives worldwide each year. It is especially daunting because vaccines are only protective when they are well matched to the strains circulating in the population. ...

Health

Can surgical masks protect you from getting the flu?

Australia has just suffered a severe flu season, with 299,211 laboratory-confirmed cases, at last count, and 662 deaths. This might be a sign of what's to come for the UK and US as the virus spreads to the northern hemisphere.

Vaccination

Free flu vaccine offered mostly in wealthy suburbs

A University of Adelaide study into the impact of state-funded vaccination programs for Australian children under five years has found those attending medical practices in the wealthiest areas were more likely to receive ...

Diseases, Conditions, Syndromes

How to stay healthy this flu season

About 40 million people contracted the flu last year, with hundreds of thousands hospitalized and 35,400 to 61,000 deaths, including 134 children, according to the Centers for Disease Control and Prevention.

Diseases, Conditions, Syndromes

Survey: many U.S. adults not planning to get flu vaccine

(HealthDay)—Many U.S. adults, including some at the highest risk for the flu and pneumonia, do not plan to get preventive vaccines, according to a survey conducted by NORC at the University of Chicago on behalf of the National ...

Diseases, Conditions, Syndromes

Busting flu vaccine myths to keep you safe

It is that time of year—flu season is upon us. While there is extensive research supporting vaccination and the impact on public health in fighting infectious disease, you may have questions about effectiveness and safety ...

Diseases, Conditions, Syndromes

From parade to pandemic: Museum looks at 1918's deadly flu

On Sept. 28, 1918, in the waning days of World War I, over 200,000 people gathered along Broad Street in Philadelphia for a parade meant to raise funds for the war effort. Among the patriotic throngs cheering for troops and ...

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Influenza

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.

This text uses material from Wikipedia, licensed under CC BY-SA