The highly contagious bacterial infection spreads through the air and infects the airways. The disease usually starts with cold- or allergy-like symptoms — runny nose, sneezing, low-grade fever and a mild cough. However, as the disease progresses in an infected person, he or she develops intense fits of rapid, dry coughing. The typical coughing spell begins suddenly as a feeling of anxiety leading to a prolonged machine-gun burst of uninterrupted coughs during which the eyes bulge and water, and the face appears purple. After a prolonged spell, the infected person finally is able to stop coughing and breathe in air, and the characteristic "whoop" sound is heard as air enters through the still partially closed airway. This sound is rarely heard in infants younger than three months of age. Vomiting often follows the coughing fits.

The disease is diagnosed through a culture taken from the nose. Babies with whooping cough often require hospitalization. Older people who have the infection can be a source of spread and must be treated with antibiotics.

While people of all ages can contract pertussis, the most seriously affected are unimmunized children. The disease can cause breathing problems, pneumonia and swelling of the brain, and can lead to seizures and brain damage; four infants died in Texas last year. Here’s how you can protect your children against pertussis:

• Make sure your children begin their DTaP immunizations at 2 months of age and continue to receive them on the recommended schedule: 4 months, 6 months, 15 to 18 months, and 4 to 6 years. This vaccine also protects against diphtheria and tetanus. It is not approved for use in people older than 7 years.
• Keep babies younger than 6 months and unimmunized children away from people who have coughs or coldlike symptoms.
• Take any infant who has a significant cough or any breathing problem to a pediatrician.