Figures show in the same period last year there was only one case in the city.

Warrnambool City Council chief medical officer Dr Philip Hall said Australia experienced an epidemic of the infection every three to four years.

“Despite long-standing immunisation, pertussis remains highly prevalent in Australia and epidemics occur every three to four years,” Dr Hall said.

“I’d like to remind people to ask their GP to review their whooping cough immunisation status.”

Dr Hall said newborns were at greatest risk of contracting whooping cough because they were not immunised against it until six weeks of age.

“Antenatal clinics have been reminding people visiting mums with new babies to make sure they are up-to-date with their whooping cough vaccines.”

Dr Hall said free booster shots were available for pregnant women and their partners if they had not been immunised against the infection in the past 10 years.

Whooping cough is a distressing and often serious illness, particularly in children aged under 12 months, according to the Victorian Department of Health and Human Services.

It is highly infectious and can be spread from person to person through close contact.

People with whooping cough usually have cold-like symptoms, followed by a cough which often ends with a high pitched ‘whoop’ when the sufferer breathes in.