[Influenza surveillance in Japan].

In Japan, under the National Epidemiological Surveillance of Infectious Diseases, clinically diagnosed influenza cases have been reported by approximately 5,000 influenza sentinel clinics and influenza virus isolation have been reported by prefectural and municipal public health institutes (PHIs). Influenza virus strain surveillance have been conducted by PHIs and National Institute of Infectious Diseases for selectin of vaccine strains. Weekly influenza case and influenza virus isolation data have been submitted to WHO FluNet website. In addition, HI antibody prevalence have been monitored by the National Epidemiological Surveillance of Vaccine-preventable Diseases. Various information about influenza surveillance in Japan is available on the Infectious Disease Surveillance Center website (http://idsc.nih.go.jp/iasr/index.html).