Adult Whooping Cough Cases May Hit 1 Million
Vaccinating Teens, Adults Could Prevent Infections, Researchers Say
Oct. 12, 2005 - Whooping cough is thought of as an illness from an earlier era, but it is on the rise in the United States.
Now a new study suggests that as many as 1 million cases could be prevented each year by routinely vaccinating teens and adults against the highly infectious respiratory disease.
About 19,000 cases of whooping cough were reported to the CDC last year, and most of them occurred in children. Experts say the disease is common, but rarely suspected, in adults and adolescents.
"The underreporting of this disease is monumental," says Joel Ward, MD, of the UCLA Center for Vaccine Research. "Physicians don't even consider it when they treat adults for persistent cough."
Childhood Immunity Often Wanes
Whooping cough, known medically as pertussis, is a highly contagious respiratory infection caused by the bacterium Bordetella pertussis that can cause coughing and choking fits.
It was a major cause of serious illness and death among infants and young children prior to the development of the pertussis vaccine in the early 1940s.
Today, children in the U.S. routinely get vaccinated before age 6. Protection typically lasts between five and 10 years after the last dose of vaccine is given.
Waning immunity is increasingly recognized as a cause of illness in teens and adults. But because whooping cough is often mistaken for other coughing-related conditions, the true incidence of the disease has not been known.
In the newly reported study, Ward and colleagues closely followed people between the ages of 15 and 65 who were or were not vaccinated against whooping cough. Immunization was found to be very effective, with just one case of whooping cough occurring in the roughly 1,400 vaccinated subjects over the next two years, compared to nine cases in those who were not immunized against the disease.
The study is reported in the Oct. 13 issue of The New England Journal of Medicine.
1 Million Cases
The study participants came from all over the country and were subjected to extensive medical testing each time they developed a coughing-related illness. This design allowed the researchers to estimate the countrywide incidence of whooping cough among adolescents and adults.