In China during March 4-April 28, 2013, avian influenza A(H7N9) virus testing was performed on 20,739 specimens from patients with influenza-like illness in 10 provinces with confirmed human cases: 6 (0.03%) were positive, and increased numbers of unsubtypeable influenza-positive specimens were not seen. Careful monitoring and rapid characterization of influenza A(H7N9) and other influenza viruses remain critical.
Keywords: China; H7N9; avian influenza; avian influenza A(H7N9) virus; influenza; influenza-like illness; subtype H7N9; surveillance; viruses.