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.

Diseases, Conditions, Syndromes

Team finds PTSD nearly doubles infection risk

First-of-its-kind study finds people with PTSD were 1.8 times as likely to have any infection as those without PTSD, ranging from being 1.3 times as likely to have meningitis, to 1.7 times as likely to have influenza, to ...

Diseases, Conditions, Syndromes

What you should know about meningitis

Getting the news your child, teenager or even their classmate or friend has meningitis can be an alarming experience. However, knowing more about the disease can help parents recognize the signs and symptoms as well as help ...

Diseases, Conditions, Syndromes

CDC: Seasonal influenza viruses circulating in southern hemisphere

(HealthDay)—Seasonal influenza viruses are circulating widely in the Southern Hemisphere, but influenza activity is currently low in the United States, according to research published in the Oct. 11 issue of the U.S. Centers ...

Vaccination

Only half of pregnant women receive recommended vaccines

(HealthDay)—Many pregnant women do not receive the recommended flu and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccines to protect themselves and their infants, according to a Vital Signs ...

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 ...

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 ...

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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 most common symptoms of the disease are chills, fever, sore throat, muscle pains, severe headache, coughing, weakness/fatigue and general discomfort. Although it is often confused with other influenza-like illnesses, especially the common cold, influenza is a 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, inaccurately, referred to as "stomach flu." Flu can occasionally cause either direct viral pneumonia or secondary bacterial pneumonia.

Typically, influenza is transmitted through the air by coughs or sneezes, creating aerosols containing the virus. Influenza can also be transmitted by direct contact with bird droppings or nasal secretions, 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 between &10000000000250000000000250,000 and &10000000000500000000000500,000 people every year, up to millions in some pandemic years. On average 41,400 people died each year in the United States between 1979 and 2001 from influenza. In 2010 the Centers for Disease Control and Prevention (CDC) in the United States changed the way it reports the 30 year estimates for deaths. Now they are reported as a range from a low of about 3,300 deaths to a high of 49,000 per year.

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" and also known as influenza A/H1N1, emerged in Mexico, the United States, and several other nations. The World Health Organization officially declared the outbreak to be a pandemic on June 11, 2009 (see 2009 flu pandemic). The WHO's declaration of a pandemic level 6 was an indication of spread, not severity, the strain actually having a lower mortality rate than common flu outbreaks.

Vaccinations against influenza are usually made available to people in developed countries. Farmed poultry is often vaccinated to avoid decimation of the flocks. The most common human vaccine is the trivalent influenza vaccine (TIV) that contains purified and inactivated antigens against 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 such as the neuraminidase inhibitor oseltamivir can be used to treat influenza, however the effectiveness is difficult to determine due to much of the data remaining unpublished.

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