Influenza epidemics occur every winter with a large number of patients and deaths, causing serious public health problems in many countries. Recently, we have obtained several new measures against influenza, such as anti-influenza drugs and rapid detection kits for influenza virus antigens in patient specimens. In addition, it is noteworthy that the use of influenza vaccines has been re-evaluated in Japan, resulting in increased vaccination rates. As it is difficult to diagnose influenza by clinical symptoms alone, virological and serological examinations are important. Although there are many methods for the detection of influenza, virus isolation is the most sensitive and reliable. Moreover, antigenic characterization of the virus can be done only by virus isolation. In recent several years, rapid diagnosis has become important in connection with the use of anti-influenza drugs. The usefulness of the detection kits has been approved and the number of the kits used has increased considerably. The effectiveness of the influenza vaccine in elderly people has been demonstrated not only in other countries but also in Japan. However, there have been few reports describing the effectiveness of the vaccine in young children. Since influenza encephalopathy in infants is a serious problem in Japan, we have to investigate the usefulness of the vaccine in this age group.

*Division of Virology, Department of Public Health, Osaka Prefectural Institute of Public Health, Osaka 537-0025