Annual report of the National Influenza Surveillance Scheme, 2000

Surveillance of influenza in Australia in 2000 was based on data from national and state-based sentinel general practice consultations for influenza-like illness, laboratory isolations of influenza virus and absenteeism rates from a national employer. The peak in influenza cases was in mid-September. Influenza A was the dominant strain, with the highest proportion being influenza A (H3N2), but with a significant proportion of isolates of influenza A (H1N1) (16%) for the first time since 1995. The influenza A (H3N2) isolates were predominantly related to A/Moscow/10/99 and vaccine strain A/Panama/2007/99. Influenza A (H1N1) was predominantly A/New Caledonia/20/99. The proportion of Influenza B viruses isolated also increased in keeping with a three-yearly cycle of influenza B epidemics in Australia. influenza B isolates showed a progressive drift away from the B/Beijing/184/93 strain with the majority closely related to the B/Sichuan/379/99 strain. In 2000, influenza vaccination levels reached 74 per cent in persons aged over 65 years.