Whooping Cough On the Rise

No longer a distant memory from the Great Depression, whooping cough has made an alarming resurgence in the United States.

Current infant vaccinations may no longer be enough, since immunity against the disease seems to wear off at adolescence, and the government is now considering a booster shot to help fight the often deadly illness.

Whooping cough, or pertussis, is a highly contagious bacterial infection characterized by violent coughing fits, gasps for air that resemble "whoop" sounds, and vomiting.

The symptoms can last for up to two months, and while an antibiotic is available to prevent spread of the disease, "it won't shorten the illness in the person already infected," says Trudy Murphy, a medical epidemiologist at the Centers for Disease Control (CDC).

Complications from the disease can include pneumonia, hernia and physical lung damage.

While incidence of the disease plunged following development of the vaccine in the 1940s, numbers have been steadily increasing since the 1970s. A preliminary CDC count estimated more than 11,000 pertussis cases in the past year, an increase of more than 2,000 from the previous year and the highest count recorded in 30 years.

Regional outbreaks have been reported across the country, from New Hampshire and Vermont to Ohio and Pennsylvania.

Whooping cough is often fatal to young babies. While older patients generally recover, they are the major source of infection for vulnerable infants. According to the CDC, the number of infants younger than 5 months reported with whooping cough grew from about 600 a year in the early 1980s to about 1,700 a year at the end of the 1990s.

Children are supposed to begin an immunization series against pertussis at 2, 4, and 6 months to confer protection, with two additional doses until their 6th birthdays. But Dr. Stephen Aronoff, chair of pediatrics at Temple University School of Medicine, says that he sees "a large number" of children above 6 months with the disease, a sign of "decreased acceptance of the vaccine by parents."

Indeed, the latest figures from the CDC show that, from 2002-2003, only about 83 percent of infants were vaccinated against pertussis. "So there is room for improvement," says Murphy.

According to Dr. Carol Stanwyck, author of a CDC study on lags in immunization for young children, pre-school vaccination policies are poorly enforced.

Aronoff says "it is well established that parents can best protect their young children from pertussis by vaccination or by moving to the moon, away from other people. Given the costs and risks of space travel, I would recommend the former."

However, "whooping cough is the only vaccine-preventable disease that has not been completely controlled by routine childhood immunization," according to Dr. John Modlin, chair of pediatrics at Dartmouth Medical School. And officials now realize the need for added measures against the disease.

Researchers have found that immunity against pertussis declines five to 10 years after the vaccine series. Concerns that this may contribute to the resurgence have prompted the U.S. government to look at a new option: a booster shot for adolescents. Canada, Germany, France and Australia currently have this kind of protocol in place.

In the United States, manufacturer GlaxoSmithKline has submitted a booster for FDA approval: "Boostrix" would add a pertussis component to the vaccine cocktail against tetanus and diphtheria that is currently given to 10- to 18-year-olds. Competitor Aventis Pasteur plans to follow suit by targeting adults as well.

Adolescents and adults who have lost immunity become more likely to get the disease, and because it is less severe in older individuals — not much more than a bad cough — it can often go undiagnosed. The problem then arises when they pass the disease on to babies.

A booster would cut down on this source of transmission, and many physicians, like Dr. Blaise Congeni, the director of infectious disease at Akron Children's Hospital, are "tremendously supportive" of the idea.

Adds Congeni, there also needs to be increased awareness among doctors about the prevalence of the disease. "Many young doctors have never made the diagnosis," he says. "If you can catch it in incubation period, you can prevent it."

And for now, according to Murphy, "the message is for parents with young infants to get your child vaccinated on time."