First the good news: The vaccine against whooping cough, also called pertussis, is very effective and has dramatically decreased the overall incidence of the life-threatening illness in this country.

Now the bad news: According to the Centers for Disease Control, the disease is on the rise. Since the 1980s, the number of people who have contracted whooping cough has risen steadily. Between 5,000 and 7,000 people in the United States still contract the disease each year (which is down from the hundreds of thousands who got it before the vaccine was created), and an average of five to 10 children die from it. The deaths tend to occur in children who are unvaccinated, either because their parents choose not to vaccinate, or because they are so young they haven't yet received their primary immunizations. Infants under one year are at the greatest risk of contracting the illness.

Whooping cough, caused by the bacteria Bordetella pertussis, is an infection of the respiratory system. The bacteria get into the lining of the breathing passages, causing inflammation and narrowing the airways. The disease starts out with symptoms like a common cold -- runny nose, sneezing, red and watery eyes, mild fever, and a dry cough -- which last for one to two weeks. If you're worried that your child's cold is something more serious, here are some signs to watch for:

• A dry cough that becomes wet, and may include coughing up stringy mucus.
  
  
• Coughing spells that last for as long as a minute, with deep inhalations between coughs.
  
  
• Signs of shortness of breath, including a bluish tint around the mouth and fingertips.
  
  
• A cough that includes a "whooping" sound (though some infants don't make this sound).
  
  
• Teary eyes, drooling, or vomiting following a coughing spell.