摘要：Surveillance of in. uenza in Australia is based on laboratory isolation of in. uenza viruses, sentinel general-practitioner reports of in. uenza-like illness, and absenteeism data from a major national employer. In 2005, 4,575 cases of laboratory-confi rmed in. uenza-like illness were reported, which was 115 per cent higher than in 2004. The in. uenza season started in the fi rst week of June, with peak activ-ity in early August, a month earlier than in 2004. In. uenza A was the predominant type notifi ed (73%), while in. uenza B activity continued to increase compared to previous years. During 2005, the in. uenza notifi cation rate amongst persons aged over 65 years (22 cases per 100,000 population) was 70 per cent higher than the mean rate of the last four years. One thousand one hundred and seventy-four in. uenza isolates from Australia were antigenically analysed: 689 were A(H3N2), 210 were A(H1N1) strains and 275 were in. uenza B viruses. Continued antigenic drift was seen with the A(H3N2) viruses from the previous reference strains with approximately one quarter of isolates being distinguishable from A/Wellington/1/2004-like viruses and more closely matched to A/California/7/2004-like viruses
关键词：in. uenza; surveillance; vaccine; in. uenza-like- llness; sentinel surveillance
