The Society for Adolescent Medicine is urging parents to be aware that their teen’s runny nose, watery eyes, and nagging cough may signal whooping cough, or pertussis.

In the society’s June 11 to June 17 survey of a nationally representative sample of 1,622 parents of 14 to 18-year-old high school students, they found that most parents were “fairly” or “very” familiar with whooping cough, but many (28 percent) were unable to identify any of its symptoms.

About half (51 percent) correctly stated that a “constant dry cough” is a warning sign of the condition and 45 percent recognized that pertussis may also cause gasping, due to airway inflammation. Only 37 percent, however, were aware that a violent coughing spell followed by vomiting is also an easily recognizable sign of the condition.

These and other survey findings prompted the Missouri-based Society for Adolescent Medicine to launch an educational campaign, “More Than Just a Cough,” to educate parents and their teenagers about pertussis.

Late last year the U.S. Centers for Disease Control and Prevention issued a report stating that whooping cough is on the rise in the United States, primarily among infants too young to have received the full series of vaccinations against the disease.

Whooping cough has also gained increasing attention lately due to news reports of outbreaks among adolescents in states such as New York, Illinois and Wisconsin. In March of this year, Reuters Health also reported on an outbreak of the condition in an Arizona middle school. Still, fewer than 20 percent of parents surveyed were concerned that their teenagers could contract the illness.

“Parents aren’t nervous about it because they don’t understand it,” Dr. Amy Middleman of Baylor College of Medicine in Houston, Texas told Reuters Health. Middleman, a specialist in adolescent medicine and a consultant with the society, explained that many parents assume their children are immune to the condition since they are vaccinated against it in childhood.

Only four percent of parents surveyed were aware that pertussis vaccinations afforded their children only limited immunity to pertussis. Twenty-four percent of parents believed the vaccination provided life-long immunity.

Recent evidence has shown that immunity begins to wane five to 10 years after the last round of vaccinations, which children receive at four to six years of age, making adolescents vulnerable to contracting the illness and spreading it to high-risk infants not yet fully immunized.

In its earliest - and most contagious - stage, whooping cough is almost indistinguishable from the common cold, Middleman explained. After a week or two, its symptoms become more specific, as the affected person experiences violent coughing with intermittent periods of breathing difficulty. During this second stage, which can last as long as six weeks, people can cough so hard that they vomit, or even pull a muscle or break ribs. This is followed by the convalescent stage, which can last for months.

If symptoms are caught very early, antibiotics can be given to shorten the course of the disease, Middleman said, noting that “there is no treatment” to cure the condition.

“Once you’ve got pertussis, you’ve got pertussis and you’ve got to let it run its course,” she said.

It’s a real problem for adolescents, since it can “interfere” with their lives, Middleman said, but in non-immunized or partially immunized infants, to whom teens can transmit the disease unknowingly during its earliest stage, the condition can be deadly.

The mortality rate is highest in kids under 3 years of age, Middleman said.

To protect against spreading the disease to infants, Middleman advises that adolescents who are experiencing cold and flu symptoms that “don’t seem quite right,” visit their doctor to get tested for pertussis.