6 June 2023

Flu cases climbing, hospitalisations steady

Communicable Disease

Those under 16 and over 65 remain most at risk, with 13 deaths registered in the past fortnight.


Flu numbers have ramped up significantly in the past fortnight, although the peak of the season looks likely to be two or three weeks later than last year.

A month ago, numbers were at the equivalent point in 2022 just before numbers exploded. In the past fortnight, it is clear this year’s season is lagging a few weeks behind 2022, but there have been 17,277 notifications to the National Notifiable Diseases Surveillance System – over double the previous fortnight (8,173).

In the year to date, there have been 57 influenza-associated deaths – 13 of them in the past fortnight. The median age of deaths notified was 76 years.

Since seasonal surveillance began in April, there have been 518 sentinel hospital admissions with confirmed influenza, of which 37 (7%) were admitted directly to ICU. The hospitalisation numbers contain some good news. There were 105 hospitalisations in the past fortnight, but overall the numbers are below the five-year average.

“While community influenza-like illness [ILI] activity remains within historical ranges, the proportion of FluTracking participants reporting ILI, and the proportion reporting taking time off regular work duties while unwell (1.06%), has continued to increase this fortnight,” said the latest Australian Influenza Surveillance Report. The previous fortnight the number was 0.92%.

“The number of laboratory-confirmed influenza notifications has also increased steeply this fortnight. It is likely that the impact on society due to the 2023 influenza season is increasing.”

Children under 15 are the most affected, with those aged five to nine recording the most notifications. Over 76% of people admitted with confirmed influenza across sentinel hospital sites were younger than 16, 14.5% were adults aged 16 to 64 years, and 9.3% were adults aged 65 years or older.

“Of children aged younger than 16 years admitted with confirmed influenza to date, 6.1% were admitted directly to ICU, compared to 16% of adults aged 16 to 64 years, and 2.1% of adults aged 65 years or older,” said the report.

Influenza A is dominating laboratory nominations (75%) with influenza B making up 23.4%.

Sentinel GP practices reported that an average of 5.3 per 1000 consultations were flu-related, up from 3.7 in the previous fortnight. Of those presenting that were tested for respiratory viruses, 58.9% tested positive. The most common virus found was rhinovirus (32.6%), SARS-CoV-2 (24.0%), influenza (24.0%), RSV (9.1%), parainfluenza virus type 2 (2.3%) and adenovirus (2.3%).

Covid was the most reported in NSW and Tasmania.

Queensland continues to have the worst flu outbreak in the country with 18,247 notifications (343 per 100,000 population), NSW (17,805; 218), and Victoria (10,343; 156).