More than 1000 whooping cough cases in the top of the south, with the outbreak continuing, have concerned health authorities stepping up prevention measures.
A free whooping cough vaccine will be available to all pregnant women from next month to help protect newborn babies from the serious disease.
The top of the south has been hit hard by the whooping cough outbreak. Nationally, there have been more than 6700 cases since August last year and one in six of those was in this region.
In Nelson, Tasman and Marlborough there have been 1084 notified cases of whooping cough, with nine babies under 1 year old requiring hospital treatment.
Nelson Marlborough Medical Officer of Health Jill Sherwood said the outbreak had continued at a significant level during spring and early summer with 11 cases in Nelson, 14 cases in Tasman and 15 in Marlborough in the past four weeks.
The contagious disease is easily spread.
"People with coughs should be especially careful around babies. Most adults don't realise they have whooping cough and how very contagious it is. We are told that every person who has it passes it on to around 17 others," Dr Sherwood said.
Babies were most vulnerable to whooping cough and people with coughs should be especially careful around them, she said.
The severe coughing could cause babies to stop breathing and could lead to blindness, brain damage, and in severe cases, death.
"Babies under 1 year old often catch it from older siblings, their parents or family members and friends."
Dr Sherwood said international research showed the most effective way to protect babies before they were immunised, was to vaccinate the mother during pregnancy so that the mother was unlikely to get the disease and infect her baby. Antibodies were also passed on to the baby to help protect the baby until they had completed the three doses of their infant vaccination series.
In Nelson Marlborough since the start of the outbreak, 18 cases have been admitted to hospital.
A total of 52 of the cases notified were babies under 1 year, and nine of them (5 per cent) were admitted to hospital.
By contrast, nine cases aged over 1 year (1 per cent) required hospital admission.
All babies and children are eligible for free immunisations against whooping cough at 6 weeks, 3 months and 5 months old. All children also receive free boosters at 4 and 11 years old.
From next month pregnant women can also be immunised for free between 28 and 38 weeks of pregnancy to protect their baby. Dr Sherwood said partners and other close family members could also consider being immunised, although this was not funded.
If people were unsure whether they or their children had been immunised, they could talk to their health practitioner, doctor or nurse.
"On time immunisation is vitally important; babies need to have had all three immunisations at 6 weeks, 3 and 5 months to be fully protected, so the longer these are delayed the more chance they have of catching the disease," Dr Sherwood said.
- The Marlborough Express