That is just under half the 23 cases for the Mid-North Coast.

The Mid North Coast Local Health District has issued a urgent warning for all pregnant women and parents to be aware of the symptoms of whooping cough and ensure they and their children are vaccinated on time.

Children with symptoms should see a doctor. If a doctor diagnoses whooping cough in a school-aged child, parents should let their school know and keep their child at home until they have taken five days of antibiotics.

"Keep coughing children away from babies. Whooping cough vaccines give good protection against infection but immunity fades. If your school-aged child has younger siblings, it's a good idea to check they are up-to-date with their vaccines," said Greg Bell, Acting Director, North Coast Public Health Unit.

Public Health Units can provide advice to schools managing whooping cough outbreaks.

Symptoms can start ,like a cold followed by a worsening cough that occurs in bouts, and may be followed by vomiting, or "whooping" breaths. The cough can last for many weeks, and can be worse at night.

Some newborns may not cough at all but stop breathing have difficulties feeding. Small babies can get very sick and may need treatment in hospital.