title: The epidemiology of influenza.
abstract: Although unpredictable, influenza outbreaks are known to occur in three patterns: pandemics every 30 to 40 years, with high excess mortality; epidemics much more frequently, with lower excess mortality; and usually mild sporadic outbreaks. The possibility of a swine-flu pandemic this winter, resembling that of 1918-20, is the result of a unique deviation in the epidemiology of this fascinating disease.
mesh_terms: D000914:Antibodies, Viral; D000956:Antigens, Viral; D004196:Disease Outbreaks / Q000453:epidemiology / Q000517:prevention & control; D000939:Epitopes; D014644:Genetic Variation; D006801:Humans; D009980:Influenza A virus; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control; D009975:Orthomyxoviridae
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D000939:Epitopes; D007252:Influenza Vaccines