At least one Bathurst school has already reported recent cases of whooping cough, also known as pertussis, and sent home a warning to parents in the weekly newsletter.

The school asked parents to be on the lookout for signs of the respiratory infection that can start out as flu-like symptoms.

And the Western NSW Local Health District yesterday confirmed that the spike in reported cases across NSW was being taken seriously.

Western NSW LHD communicable diseases co-ordinator Priscilla Stanley said whooping cough was a notifiable disease, meaning medical practitioners, hospitals, pathology laboratories and schools must report all cases to the Public Health Unit.

"The communicable diseases team monitors the numbers of pertussis across the Health District and takes necessary actions to assist clinicians to prevent the further spread of disease," Ms Stanley said.

"The numbers across the health district are being closely monitored at this time as there has been an increase in numbers reported across the state."

Ms Stanley said vaccination rates against whooping cough were relatively high across the Western NSW LHD.

"The Health District can confirm that vaccination rates for whooping cough/pertussis are between 93 per cent and 96 per cent which meets NSW state average," she said.

Whooping cough starts like a cold with a blocked or runny nose, sneezing, a mild fever and an occasional cough. The cough usually gets worse, and severe bouts of uncontrollable coughing develop.

This can be followed by vomiting, choking or taking big gasping breaths which causes the 'whooping' sound.

The cough can last for many weeks and can be worse at night.

Some older children and adults just get a cough that doesn't go away and may not get any other symptoms.

The spokeswoman said whooping cough is highly infectious in the first three weeks of a person's illness and can spread easily through families, childcare centres and schools.