title: Update: Influenza activity--United States and worldwide, June-September, 2002.
abstract: During June-September 2002, influenza A (H3N2) and B viruses circulated worldwide and were associated with mild to moderate levels of disease activity. Influenza B viruses predominated in Africa, and both influenza A (H3N2) and B viruses circulated widely in Asia, Oceania, and Latin America, except in Chile and Taiwan, where A (H1) viruses predominated. In North America, sporadic isolates of influenza A (H3N2), A (H1), and B viruses were identified. This report summarizes influenza activity in the United States and worldwide during June-September 2002. Influenza activity in North America typically peaks during December-March, which underscores the need to begin vaccinating against influenza in October and to continue vaccination into December and throughout the influenza season.
mesh_terms: D014943:Global Health; D006801:Humans; D009980:Influenza A virus; D009981:Influenza B virus; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000453:epidemiology* / Q000517:prevention & control; D012621:Seasons; D014481:United States / Q000453:epidemiology
chemical_list: D007252:Influenza Vaccines