influenza

influenza
n.
a highly contagious virus infection that affects the respiratory system. Types A and B are the forms that most commonly cause outbreaks in humans. The viruses are transmitted by coughing and sneezing. Symptoms commence after an incubation period of 1–4 days and include headache, fever, loss of appetite, weakness, and general aches and pains. They may continue for about a week. With bed rest and aspirin most patients recover, but a few may go on to develop pneumonia, either a primary influenzal viral pneumonia or a secondary bacterial pneumonia. Either of these may lead to death from haemorrhage within the lungs. The main bacterial organisms responsible for secondary infection are Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus, against which appropriate antibiotic therapy must be given.
An influenzal infection provides later protection only against the specific strain of virus concerned; the same holds true for immunization. Strains are classified according to the presence of different subtypes of two glycoproteins (antigens) on the viral surface: haemagglutinin (H) and neuraminidase (N). Small changes in the structure of these antigens, which occur frequently in influenza A and B viruses, require the continual development of new vaccines to protect against annual outbreaks of the disease. Major changes in antigenic structure occur much more rarely, when there is genetic recombination between strains that can infect more than one species (most strains of the virus are highly species-specific). However, when it does occur, it could result in the development of hybrid strains causing new forms of influenza that are difficult to contain; the pandemic of 1918–19 is thought to have arisen in this way (see also avian influenza).

The new mediacal dictionary. 2014.

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  • influenza — [ ɛ̃flyɑ̃za; ɛ̃flyɛnza ] n. f. • 1782; it. influenza « écoulement de fluide, influence », d où « épidémie » ♦ Vieilli Grippe. ● influenza nom féminin (anglais influenza, de l italien influenza) Synonyme vieilli de grippe. ● influenza (synonymes)… …   Encyclopédie Universelle

  • influenza A — ā n a common moderate to severe respiratory disease that affects humans and some other vertebrates (as swine and birds) sometimes in pandemics following mutation in the causative virus, that in humans is characterized by sudden onset, fever,… …   Medical dictionary

  • influenza B — bē n influenza that is usu. milder than influenza A, that may occur in epidemics but not pandemics, and that is caused by an orthomyxovirus (species Influenza B virus of the genus Influenzavirus B) infecting only humans and esp. children and… …   Medical dictionary

  • influenza C — sē n influenza that is restricted to humans, that usu. occurs as a subclinical infection, that occurs in neither epidemics or pandemics, and that is caused by an orthomyxovirus (species Influenza C virus of the genus Influenzavirus C) * * *… …   Medical dictionary

  • Influenza — Sf Grippe per. Wortschatz fach. (18. Jh.) Entlehnung. Entlehnt aus it. influenza, eigentlich Einfluß (der Sterne) , dieses aus ml. influentia Einfluß , zu l. influere hineinfließen , zu l. fluere fließen und l. in . Seit dem 15. Jh. bedeutet das… …   Etymologisches Wörterbuch der deutschen sprache

  • influenza — 1743, borrowed during an outbreak of the disease in Europe, from It. influenza influenza, epidemic, originally visitation, influence (of the stars), from M.L. influentia (see INFLUENCE (Cf. influence)). Used in Italian for diseases since at least …   Etymology dictionary

  • Influenza — In flu*en za, n. [It. influenza influence, an epidemic formerly attributed by astrologers to the influence of the heavenly bodies, influenza. See {Influence}.] (Med.) An epidemic viral infectious disease characterized by acute nasal catarrh, or… …   The Collaborative International Dictionary of English

  • Influenza — Influenza, 1) so v.w. Grippe; 2) seuchenartiges Katarrhalfieber der Pferde; tritt sehr versteckt auf, verläuft schnell u. ist gefährlich. Sie tritt theils als rheumatische, theils als katarrhalische, theils als gastrische Form auf. Das Thier… …   Pierer's Universal-Lexikon

  • influenza — (Del it. influenza). f. gripe …   Diccionario de la lengua española

  • influenza — ► NOUN ▪ a highly contagious infection of the respiratory passages, spread by a virus and causing fever, severe aching, and catarrh. DERIVATIVES influenzal adjective. ORIGIN Italian, influence, outbreak of an epidemic , from Latin influere flow… …   English terms dictionary

  • Influénza — (ital), soviel wie Grippe (s. d.). – Als I. der Pferde bezeichnete man früher verschiedene fieberhafte akute Infektionskrankheiten, die heute wissenschaftlich als Brustseuche, Pferdestaupe und Skalma unterschieden werden. Der Name I. ist damit… …   Meyers Großes Konversations-Lexikon

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