In 2008, whooping cough killed 195,000 people globally, according to the World Health Organization.
Whooping cough is caused by a bacterial infection. It gets its name from the nagging cough it causes that can make children breathless. They often gasp for air, making a distinctive whooping sound. But it's not so serious in adults and they may not realize that a persistent cough is being caused by pertussis.
Washington state is having an especially bad time with whooping cough this year, with 3,000 cases so far, compared to 20 at the same time last year, said Mary Selecky, secretary of the Washington State Department of Health. "For every case that we know about, we suspect that there are many people out there who have pertussis and don't know it,' Selecky said.
"In many cases, babies get this illness from their mothers or others close to them. It's absolutely tragic."
The state has distributed 27,000 doses of a booster vaccine for uninsured adults and has ordered more. "This disease is very easy to catch," Selecky said. "It has certainly gotten hold of our population in Washington state."
The CDC is trying to figure out what's going on, but Schuchat said a couple of factors are clearly at work. The formulation for the whooping cough vaccine was changed in 1997, and kids hitting age 13 and 14 now are the first to have been fully vaccinated with five doses of the new vaccine. The new formulation causes less of a reaction, but it may also wear off sooner, Schuchat said.
The older vaccine was made using a whole pertussis bacterium. It was very effective, but it did cause swelling in some kids who got it, and sometimes caused a fever -- something that scared parents. It also was widely blamed for causing rare but serious neurological reactions, although Schuchat said studies have not confirmed this.
"Vaccines have done a good job of reducing the incidence of pertussis but our vaccines aren't perfect," Schuchat said. "We wish we had better ways of controlling pertussis. Given how dangerous pertussis is for babies, preventing infection in babies is our priority."
320 Division Street
P.O. Box 1490
Lake Charles, LA 70601/70602