文档介绍：Influenza
02Mar2015
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Contents
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Introduction
Pathogenesis 病理
Epidemiology 流行病学
Clinical Features
Prophylaxis and Treatment
mendations
Phases in clinical trial
Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae(正粘病毒科)
Introduction
Although it is often confused with other influenza-like illnesses, especially mon cold, influenza is a more severe disease caused by a different type of virus.
Influenza spreads around the world in seasonal epidemics, resulting in the deaths of between 250,000 and 500,000 people every year
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Classification
In virus classification, there are three types of influenza viruses: A, B and C viruses(变异性强).
Influenza A and B viruses are the major human pathogens and are morphologically(形态) similar
The type A viruses are the most virulent(恶性) human pathogens among the three influenza types and cause the most severe disease.
Introduction
ination
The most effective way to prevent influenza, ination annually, WHO
ination against influenza with an influenza ine is often mended for high-risk groups, such as children and the elderly, or in people who have asthma, diabetes, heart disease, or are promised(免疫损害患者).
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Known flu pandemics
Introduction
Name of pandemic
Date
Deaths
Case fatality rate
Subtype involved
Asiatic (Russian) Flu
1889–1890
1 million
%
H3N8
1918 flu pandemic (Spanish flu)
1918–1920
20 to 100 million
2%
H1N1
Asian Flu
1957–1958
1 to million
%
H2N2
Hong Kong Flu
1968–1969
to 1 million
<%
H3N2
2009 flu pandemic
2009–2010
18,000
%
H1N1
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Seasonal variations
Influenza reaches peak prevalence in winter,
Epidemics begin abruptly, peak over 2-3 weeks, last 2-3 months, and then subside rapidly.
Risk factors for severe illness
Chronic cardiac and pulmonary disease and old age are prominent risk factors
Epidemic and pandemic spread
From a public health point of view, flu epidemics spread rapidly and