Whooping cough cases rising as parents warned of risk to infants

Cases of the respiratory illness, also known as pertussis, have increased in Victoria, New South Wales and Queensland in 2024, Victoria's acting chief health officer Dr Evelyn Wong said.

So far in 2024 there have been around four times the number of pertussis cases in Victoria than for the whole of 2023, the health advisory said.

Kids aged between 10 and 12 years old account for one third of whooping cough cases reported in 2024.

"Population-wide increases in pertussis typically occur every few years," Dr Wong said.

"The increasing number of pertussis infections seen in Victoria is a public health concern, as it indicates an increasing risk of transmission to the most vulnerable population - infants under the age of 6 months."

The highly contagious illness is known for causing a distinctive cough but symptoms may be indistinguishable from other respiratory infections in early stages.

The cough comes in long spells and may be followed by a high-pitched "whooping" sound on inhalation or by vomiting in toddlers and older children after a coughing fit, the Victorian Department of Health said.

The illness affects all age groups but babies less than 6 months old are "at greatest risk of severe disease, hospitalisation, and death", the department said.

Immunisation is recommended and free vaccines are available for children, pregnant women and refugees and humanitarian entrants.

Vaccinated people may still contract pertussis, but their symptoms are likely to be less severe, and they are less likely to transmit the infection to others, the Victorian Department of Health said.

Dr Wong said whooping cough needs to be diagnosed and treated immediately.