title: Update: influenza activity--United States and worldwide, May 19-September 28, 2013.
abstract: During May 19-September 28, 2013,* the United States experienced low levels of seasonal influenza activity overall. Influenza A (H1N1) pdm09 (pH1N1), influenza A (H3N2), and influenza B viruses were detected worldwide and were identified sporadically in the United States. In June, influenza A (H3N2) variant(†) viruses (H3N2)v were first detected in Indiana, and between June 18 and September 28, a total of 20 cases of influenza A variant viruses ([H3N2]v and influenza A (H1N1) variant [H1N1]v) were reported from five states. This report summarizes influenza activity in the United States and worldwide from May 19 through September 28, 2013.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D014943:Global Health / Q000706:statistics & numerical data*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D053122:Influenza A Virus, H3N2 Subtype; D009981:Influenza B virus; D007251:Influenza, Human / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012621:Seasons; D014481:United States / Q000453:epidemiology; D055815:Young Adult