Doctors expect that a sharp surge in flu cases this week is only the start of a rise in people falling ill to the virus this winter.
ACT Deputy Chief Health Officer Dr Andrew Pengilley has urged Canberrans to stop its spread by staying home from work and keeping their families at home from childcare and school if they are sick.
Of the 186 reported cases between January and July 11 this year, one-fifth of patients fell ill from the flu in the last week.
"This spike in reported cases is signalling the start of the flu season here locally with the number of cases expected to continue to rise in the coming weeks," Dr Pengilley said.
"As people tend to spend more time indoors having closer contact with one another during the winter months, the flu is spread more easily from person to person.
"That's why today we're asking Canberrans to work with us in protecting the community against the flu by staying away from childcare, school, work and other social activities while infectious and unwell."
Dr Pengilley also urged people to prevent the spread of flu through basic hygiene, and said it was not too late to get a flu vaccination.
"For those who are already unwell, the best way to manage the flu is to drink plenty of fluids, get plenty of rest and treat symptoms as they occur. Canberrans can also seek further medical advice from their GPs."