Diseases, Conditions, Syndromes

Q&A: Even the young and healthy benefit from the flu vaccine

Dear Mayo Clinic: I am 28 and healthy. I have never gotten a flu shot and have never had the flu. Do I really need a flu vaccination? My employer is recommending it for everyone, but I am hesitant. I have heard some people ...

Diseases, Conditions, Syndromes

Lung neuropeptide exacerbates lethal influenza virus infection

Severe influenza virus infection is characterized by a strong inflammatory response and profuse viral replication in lungs. These viruses, such as the notorious avian flu, have a high rate of death and to date there are no ...

Diseases, Conditions, Syndromes

Respiratory microbiome may influence your susceptibility to flu

Specific respiratory microbiome communities may be linked to influenza susceptibility, according to a study published January 9, 2019 in the open-access journal PLOS ONE by Betsy Foxman from the University of Michigan, USA, ...

Pediatrics

Newborns face risks when born to women with the flu

Pregnant women with influenza are more likely to experience complications, but how this affects infants is unclear. A new Birth Defects Research study uncovers the potential risks to infants.

Diseases, Conditions, Syndromes

In-hospital morbidity, mortality up with flu in heart failure

(HealthDay)—For patients with heart failure, influenza infection is associated with increased in-hospital morbidity and mortality, according to a study published online Jan. 3 in JACC: Heart Failure.

Diseases, Conditions, Syndromes

Q&A: There are new vaccine options to help protect against influenza

Dear Mayo Clinic: I've read that there will be new options for getting the flu vaccine this year, including one for people who have egg allergies. How are these new vaccines different, and how do I know which one to pick? ...

Diseases, Conditions, Syndromes

Flu is serious for pregnant women and others at high risk

Pregnant women and the extremely obese are among those at high risk for complications from the flu—including death—and should be tested and begin antiviral treatment promptly if they are sick enough to be hospitalized ...

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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