Southern big hotspot for whooping cough

These rod-shaped Gram-negative bacilli cause whooping cough, known as pertussis, mainly in infants. Photo: Getty Images

The lower North and South Islands are the biggest hotspots for whooping cough as an epidemic sweeps the country, official data shows.

Health officials declared a whooping cough epidemic on Friday and put a nationally coordinated response in place.

There have been 263 cases of whooping cough in the four weeks to November 15 - the highest number of cases over a month to date for all of 2024, Te Whatu Ora/Health NZ said.

The latest data collated by ESR showed the highest rates of infection were in Wairarapa, Southern, Whanganui and Capital and Coast health districts.

It broke down rates of infection in the four weeks to November 8.

Wairarapa had 13 cases, which was by far the highest rate at 25.4 cases per 100,000 people.

That was followed by Southern at 11.6 (42 cases), Whanganui at 11.4 (8 cases) and Capital and Coast at 10.4 (34 cases).

Te Whatu Ora was urging people to get vaccinated, and said babies are particularly vulnerable to the life-threatening infection.

"Around 50 percent of pēpi who catch whooping cough before the age of 12 months need hospitalisation and 1 or 2 in 100 of those hospitalised pēpi die from the infection," public health medicine specialist Dr Matt Reid said.

"While there have been no deaths so far during 2024, sadly, three infants died last year from whooping cough, and we want to stop that from happening again."

Whooping cough: What you need to know

• Childhood vaccinations to protect against whooping cough are needed at ages six weeks, three months and five months, and again at four years.

• A further booster is given at age 11 years (school year 7).

• Vaccination free for pregnant people.

• Adults are eligible for one free booster from age 45 (if they have not had four previous tetanus doses) and can get one free from age 65.

• Whooping cough causes breathing difficulties and severe coughing fits. The cough can go on for weeks or months which is why it is sometimes called the "100-day cough". 

• People are most infectious in the early stages - with the first signs of whooping cough usually appearing around 1 week after infection.