Whooping Cough Cases Surge in Western Australia's South

Parents in Western Australia's south are being urged to get their children vaccinated against whooping cough, as cases in the region surge to more than three times last year's numbers.

The highly contagious bacterial infection, known formally as pertussis, is spread through droplets emitted when a person coughs or sneezes.

Pertussis can be fatal in young children and infants, with the distinct whoop-sounding cough lasting weeks or even months.

Data: WA Country Health Service

This year, the Great Southern has recorded 117 diagnosed cases, the highest figure in regional WA and a sharp increase from last year's total of 38.

Rural Doctors Association of WA president Thomas Drake-Brockman said the rising case numbers were concerning.

"Whooping cough is a vaccine-preventable disease," Dr Drake-Brockman said.

Cases to rise

WA Country Health Service (WACHS) doctor Alexander Shivarev said case numbers were expected to rise as up to 70 per cent of those ill were school-aged children.

"We're seeing a significant proportion not being vaccinated, only partially vaccinated, or haven't had any of the pertussis containing vaccines recently," he said.

Outbreaks like this were not unexpected, he said.

"We do get these periodic epidemics of whooping cough, usually every five years or so, but obviously the COVID-19 pandemic disrupted that usual cycle," Dr Shivarev said.

"We get this repeated resurgence of pertussis because immunity does wane over time."

Low vaccination rates drive spike

Dr Drake-Brockman said vaccine hesitancy post-COVID was a factor in the regional outbreak.

"Ultimately it comes down to declining vaccination," they said.

"There's certainly pockets of the Great Southern where rates are a little bit lower."

In 2025, more than 85 per cent of children in the Great Southern region were vaccinated against pertussis, down from just over 92 per cent in 2021.

Data: WA Country Health Service/Australian National Immunisation Register

Dr Drake-Brockman said the decline in vaccination rates in the Great Southern mirrored a broader trend across regional WA, which was fuelled by online disinformation.

"We really need these to be above 95 per cent to have effective herd immunity," they said.

Vaccination best defence

Public health researcher Jaya Dantas, from Curtin University, said whooping cough did not just affect children.

"Adults can get whooping cough, and immunity from the childhood vaccine fades over time," she said.

Under the National Immunisation Program, combination whooping cough vaccines are free for:

Children aged two months, four months, six months, 18 months and four years

Adolescents aged 12-13 years through school-based vaccination programs

Pregnant women, ideally between 20-32 weeks

A booster shot is recommended every 10 years after vaccination, at a cost of about $50-70.

Dr Drake-Brockman said it was a small price to pay for protection.

"It's well worth the $7 a year."