title: Update: influenza activity - United States and worldwide, May 20-September 22, 2012.
abstract: During May 20-September 22, 2012, the United States experienced low levels of seasonal influenza activity overall; however, more seasonal influenza viruses were detected than in the summer months of previous years. Influenza A (H1N1)pdm09 (pH1N1), influenza A (H3N2), and influenza B viruses were detected worldwide and were identified sporadically in the United States. In July, influenza A (H3N2) variant viruses (H3N2v) were first detected in Indiana, and since July 12, a total of 306 cases have been reported from 10 states. This report summarizes influenza activity in the United States and worldwide since May 20, 2012.
mesh_terms: D000293:Adolescent; D000368:Aged; D002648:Child; D002675:Child, Preschool; D024882:Drug Resistance, Viral; D005260:Female; D014943:Global Health; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000302:isolation & purification; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology*; D008297:Male; D011159:Population Surveillance; D012621:Seasons; D014481:United States / Q000453:epidemiology