Annual report of the National Influenza Surveillance Scheme, 1999.
An effective national surveillance system is an essential component of a program for the control of influenza. The National Influenza Surveillance Scheme includes data from sentinel general practice consultations for influenza-like illness, laboratory reports of influenza and absenteeism rates from a national employer. The 1999 season peaked between May and September with maximal activity between July and August. Influenza A was the dominant type in all States and Territories with influenza A H3N2 viruses predominating and influenza A H1N1 occurring sporadically. There was no evidence of significant drift among the H3N2 isolates (A/Sydney-like strains) whereas the H1N1 isolates showed significant antigenic changes from the vaccine strain A/Beijing/262/95 and were closely related to a new variant A/New Caledonia/20/99. A small peak in influenza B activity occurred towards the end of the influenza season and isolates remained closely related to the vaccine reference strain B/Beijing/184/93.
Thomson
J
J
National Centre for Disease Control, Department of Health and Aged Care, Canberra, Australian Capital Territory, Australia. Jenny.Thomson@health.gov.au
Lin
M
M
Hampson
A
A
D000956:Antigens, Viral / Q000032:analysis; D001315:Australia / Q000453:epidemiology; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology*; D009975:Orthomyxoviridae / Q000276:immunology / Q000302:isolation & purification; D012042:Registries / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012621:Seasons; D018571:Sentinel Surveillance
D000956:Antigens, Viral