SA flu cases spike over summer

The number of South Australians struck down by the flu has spiked to a six-year high.

SA Health says there have been 504 confirmed influenza cases so far in 2017, up from 173 over the same period in 2016 and a mere 49 in 2012.

The department says a late peak in the 2016 flu season, which carried over to the summer, has partly contributed to the steep increase.

But Chief Medical officer Paddy Phillips says the spike does not necessarily mean this year's flu season will be a cause for concern.

"It's not possible to predict the severity of a flu season or whether it will commence early," he said in a statement.

"The most important thing to do is to protect yourself by getting an annual flu vaccination."

SA Health said the influenza vaccination, which changes each year to match particular virus types, is usually available from late March or early April.