The beginnings of a whooping cough outbreak across the country

There've been 182 cases in the year to date - substantially more than we've seen in the past few years.

Otago University Professor Peter McIntyre says case numbers tripled from April to May this year - and if that continues, we could see similar levels to one of the big outbreak years.

He says whooping cough causes a long period of coughing, disturbed sleep and sometimes can be so bad people fracture a rib.

He says a real worry is that babies can die from it..and is advising families to stay on top of immunisations.