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in·flu·en·za(in'flū-en'ză), The colloquial word flu is often loosely applied to any acute viral syndrome, including gastroenteritis ("intestinal flu"). Influenza, however, is a specific respiratory infection with a well-defined cause, and gastrointestinal symptoms seldom occur.
Influenza viruses are divided on the basis of antigenic structure into three types. Influenza A virus is principally responsible for epidemics; subtypes of influenza A virus affect birds, horses, and swine as well as human beings. Incidence of influenza B is lower and epidemics are less likely to occur with this virus, for which animal reservoirs are apparently of little importance. Influenza C infection is typically mild or subclinical. The annual mortality of influenza in the U.S. is believed to exceed 50,000, more than 90% of these deaths occurring in people 65 years of age or older. Influenza deaths have increased substantially in the past 20 years, in part because of the aging of the population. At least 30 pandemics of influenza have occurred since 1580. The influenza A pandemic of 1918-1920 ("Spanish flu") caused more than 20 million deaths worldwide, 500,000 of them in the U.S. Less devastating pandemics occurred in 1957 ("Asian flu") and 1968 ("Hong Kong flu"). Influenza is highly contagious. The virus is transmitted from person to person by direct contact and by airborne droplets of respiratory secretion expelled through coughing and sneezing. Incidence is highest in late fall, winter, and early spring. Active immunization with noninfective vaccines containing hemagglutinin (H) and neuraminidase (N) antigens of currently prevalent strains has reduced the extent and severity of epidemics and has provided protection to vulnerable populations such as the elderly. Vaccines are especially recommended for people older than 50 and those with certain chronic conditions, including diabetes mellitus, immune deficiency, impairment of renal function, and cardiac and pulmonary disease. Immunity arising from either natural infection or vaccination confers protection only against certain strains of virus. Antigenic drift results from the gradual accumulation of new epitopes on viral H and N molecules, whereas antigenic shifts are caused by mutations in the genes that encode these molecules. A new strain probably emerges as a human pathogen when that strain is transmitted to human beings from animal hosts. Influenza cannot be diagnosed with certainty or differentiated from other acute febrile syndromes on clinical evidence alone. Diagnosis can only be confirmed by detection of viral antigen in nasal secretions by direct immunofluorescence or by a rising titer of antibody to influenzal hemagglutinin. The antiviral drugs amantadine and rimantadine (effective only against influenza A) and the neuraminidase inhibitors oseltamivir and zanamivir can prevent clinical illness when taken prophylactically during an outbreak or epidemic and can reduce the severity and duration of symptoms (average reduction in duration with all agents, one day) when administered within 24-48 hours after the onset of illness. An international network for influenza surveillance was established by the World Health Organization in 1948. Now consisting of 110 centers in 83 countries, the network monitors influenza activity worldwide, facilitates rapid identification of viral strains, and provides information used in determining the composition of influenza vaccines.
fluInfluenza, see there. See China flu, Hong Kong flu.
Synonym(s): flu, grip, grippe.
Synonym(s): flu, grippe.
Patient discussion about flu
Q. INFLUENZA(FLU) is it a fatal disease?
Q. How flu is passing? I have too small children, and in the class of the older one there’s an outbreak of flu with many sick children. The last time my little son had the flu was like a hell for him, and I really won’t to prevent it. What can I do?
However, simple measures, such as covering the nose and mouth while sneezing or coughing and washing hands thoroughly may minimize the transmission of the flu from child to child.
Q. Who Should Receive the Flu Vaccine? Should I go get vaccinated for the flu? I have been told it is advised only for certain people, so who should receive this vaccine?
at the bottom you will also find links in english. vaccinations in general are very disputable/dubious and it is probably time that we learn about it.