Australia Faces Late-Season Influenza Surge as Cases Rise Sharply
Canberra, September 18, 2026: Australia is experiencing an unusual rise in influenza infections as the country moves into spring, with health authorities and medical experts warning that flu activity is continuing to increase despite the end of the traditional winter season.
National respiratory surveillance data recorded 31,650 influenza notifications during the two-week period ending September 6, representing a 27.2 percent increase from the previous reporting period. New South Wales recorded 14,256 cases, followed by Victoria with 7,039 and Queensland with 6,625.
Significant Increase Reported in Victoria
Victoria has experienced one of the sharpest increases in influenza activity. Notifications in the state have risen by about 400 percent over seven weeks, with influenza A accounting for most reported infections.
Health authorities have also observed a rise in emergency department presentations involving acute respiratory infections. These visits increased by approximately 25 percent over six weeks, with children aged between 5 and 17 particularly affected.
Flu Season Extending Into Spring
Australia’s current pattern differs from the usual seasonal trajectory, as influenza activity has continued to climb after winter.
Victoria’s Chief Health Officer, Dr Caroline McElnay, said the state’s flu season had arrived later than in previous years and cases were continuing to increase as spring progressed. Experts cited several possible factors, including changes in population immunity and vaccination levels.
Influenza A(H3N2) is currently the dominant strain, while A(H1N1) has also been increasing in some areas.
Vaccination Remains an Important Protection
Health experts are encouraging eligible people to consider influenza vaccination, particularly as substantial numbers of Australians remain unvaccinated.
National influenza vaccination coverage was reported at around 30.2 percent, leaving many people without vaccine protection as transmission remains elevated.
Experts have also pointed to changing weather conditions, increased indoor gatherings and differences in population immunity as factors that may contribute to continued transmission.
Children Among Those Affected
The increase in respiratory-related emergency department visits among school-aged children is another notable feature of the current season.
Health officials are continuing to monitor influenza trends as Australia enters spring, while healthcare services prepare for the possibility that elevated transmission could persist beyond the period normally associated with peak flu activity.
The late-season rise highlights the importance of continued respiratory disease surveillance and preventive measures even after the traditional winter influenza period has ended.
