More than half the number of whooping cough cases in Western Bay of Plenty have involved adults who have unwittingly helped spread the disease to epidemic proportions.
Nationally the number of adults with whooping cough, also known as pertussis, has soared in recent years. Institute of Environmental Science and Research figures showed 5900 notifications of the disease reported last year, more than double the 2014 reported in 2011, and the rate of hospitalisation for people aged 30 to 70 increased markedly last year compared with 2011.
Of the 309 people treated in hospital for the illness last year, two died, and 182 were aged under 1.
Toi Te Ora Public Health Service medical officer of health Dr Phil Shoemack said the Western Bay of Plenty was "very much" part of the epidemic, which began in the Canterbury area in 2011.
It has since spread across New Zealand and unwitting, infected adults were the reason why, including those who had vaccines as children.
"With pertussis it does seem to wane over time and one of the consequences of this is that adults are often responsible for spreading it to children."
Infected adults did not suffer the same severity of the disease as infants did.
"By the time most adults are diagnosed, they usually just have a hacking cough for a few weeks which begins to annoy them, so they go to a doctor - by which stage they are likely to have infected others around them."
A Tauranga woman, who would only be known as Donna, said she fell ill the week before Christmas and her voice still had not come right two months later.
"I got really sick. It had been a scratching there for nearly a week. Then suddenly it was a coughing. Christmas Day was coughing all day and then I woke up on Boxing Day not being able to breathe.
"It was hideous actually."
Donna, in her 50s, went to Accident and Emergency at 2nd Ave where she was diagnosed and ordered to stay away from work for at least three weeks.
She said she was shocked, especially after being told she could have passed the disease on to her granddaughter.
"I had no idea I was infected. It was awful. It was two weeks then my husband came down with it. They say it's the 100-day cough."
Dr John Gemming said he noticed a significant number of adults who have had whooping cough, especially over the past 12 to 18 months.
Any adults having trouble shaking off a dry, hacking cough are recommended to consult their GP and children are encouraged to be vaccinated.
While there was no treatment to help shorten the length of time of symptoms, antibiotics could be given to help prevent the spread of infection. Toi Te Ora were offering a free vaccine for all pregnant women between 28 and 38 weeks of pregnancy from their GP. Other adults caring for infants were advised to consider having a booster. More information is available on 0800 IMMUNE or www.immune.org.nz.
By the numbers
Whooping cough cases in the Western Bay of Plenty in the past year:
7 babies aged under 1 year
26 aged 1-4 years
42 from 5-20 years
63 from 20-49 years
33 from 50-69 years
5 people aged over 70