Despite almost 95 per cent of infants in the region and across the state vaccinated against the disease, outbreaks still occur every three to four years as community immunity wanes.

Illawarra Shoalhaven Local Health District (ISLHD) public health director Curtis Gregory said recent high figures locally, and statewide, indicated an outbreak may be on the way.

Last month, almost 1000 people in NSW were notified with whooping cough (pertussis) – compared to 402 notifications of the disease in November 2017.

In the ISLHD, there were 28 whooping cough notifications last month, in contrast to just seven the previous November.

Of the 28 notifications in the region last month, 26 were for children five years and older, with two notifications in the under-fives age group.

“In the last couple of months we have seen a rise in cases so we’re keeping our eye on things as we know immunity fades over time leading to periodic spikes or outbreaks of the disease,” Mr Gregory said.

“This year to date we have seen 147 cases in the five years and older age group, and 25 cases in children less than five years.

“It’s the under-fives who are at highest risk as they tend to have the more severe symptoms, and due to the immunisation schedule may not yet be vaccinated.”

Mr Gregory said on-time vaccination of infants was important, with the first dose due at six weeks, followed by doses at four months and six months of age. Boosters are due at 18 months, four years and in the first year of high school.

“In NSW, pregnant women can get vaccinated for whooping cough for free,” he said. “It’s recommended in the third trimester – around 28 weeks – so they can pass on some of that protection to their newborn.”

Grandparents, carers, health professionals, childcare workers and others who are around young babies are also urged to get the vaccine.

Meanwhile those suspected of whooping cough should stay home until they have completed a five-day course of antibiotics. GPs can diagnosis the disease with a simple swab.

“Whooping cough is often difficult to diagnosis as it begins like the common cold – with symptoms such as a blocked or runny nose, tiredness and mild fever,” Mr Gregory said.

“Then it develops into an uncontrollable cough which can be so severe it results in vomiting.

“In the worst case scenario whooping cough can lead to severe symptoms in babies and young infants including seizures, brain damage and in some cases death.

“Vaccination is the best protection, and even if people do still catch it they are likely to have less severe symptoms, be less infectious to others and have the disease for a shorter period of time.”

Good personal hygiene was also important for prevention.