Vicky Sheppeard, Sydney West Area Health medical officer of health, said despite some reduction in the rate of new cases of whooping cough compared with several months ago, people in western Sydney continued to be affected.

Dr Sheppeard said whooping cough was spread by sneezing or coughing: ``You can be infectious for up to three weeks from the start of the cough and can easily

spread the disease to family members, other children in child care or school, or work colleagues.''

She also said it was particularly dangerous for young babies who had not received all their vaccinations.

``Children, parents and people in regular contact with babies should be vaccinated,'' she said.

She said the vaccine Boostrix, which also protects against diphtheria and tetanus, was available at no cost through general practitioners for new parents or people who regularly cared for infants.

``Adults can have this vaccine any time, even if they have recently had a tetanus booster,'' she said.

Children are usually vaccinated against whooping cough at the age of two, four, six and 18 months and need a booster when they are 15 years old.

Penrith residents are being asked to look out for whooping cough symptoms

Dr Vicky Sheppeard said it usually started like an ordinary cold and developed into a persistent cough and may be followed by a deep gasp or `whoop'

People with symptoms should seek medical attention, special antibiotics are available to effectively treat it and stop the spread to other people

A doctor can take a swab from the back of the nose or a blood test to confirm a diagnosis

Details: talk to your GP or call the Public Health Unit, 4734 2022.