Knoxville (WVLT) - If you were born after 1940, you were likely vaccinated against whooping cough as part of your routine immunizations.
So, how is it possible more cases of whooping cough are being reported now?
Medical Reporter Jessa Goddard takes a look at the disease and who's most at risk.
At its peak in the 1920's and 30's, the number of cases in the US was more than 250,000, when a vaccine was introduced in the 1970's that number dropped to about a thousand.
Now whooping cough is once again slowly on the rise.
The first symptoms of whooping cough are similar to those of the common cold, runny nose, sneezing, mild cough, low-grade fever.
After a week or two, the mild cough evolves into coughing spells that can last more than a minute.
Today, it's treated with antibiotics, but pertussis will never be eliminated.
"And whooping cough is one of those bacteria that's just so our there, it can spring up and there are outbreaks, you know, every few years there are outbreaks in isolated communities," explains pediatric Doctor Michael Green.
And it is highly contagious.
An increasing number of cases have been reported to the CDC, some among infants less than six months of age, who have not yet built up immunity through their vaccinations.
But primarily it's showing up in a new population, teens and young adults.
"And then there are some of us who develops immunity along the way, and that's kind of the adolescents, that's kind of a new population that we're trying to treat. That's from about 11 to about 15," says Dr. Green.
Pediatricians believe more cases are being reported in teens and adults, because their immunity has faded since their original vaccination.
In fact, in Knox County, about eight cases are reported on average every year, but last year, there were 15.
"It's definitely a concern because again this is very contagious and can be spreading easily. And so you do kind of need to constantly keep it in the forefront of your mind," Dr. Green says.
That's why pediatricians now recommend 11 to 18 years olds get a booster shot that contains pertussis, preferably when they're 11 or 12.
Call your doctor if you suspect your child has whooping cough or has been exposed to someone with it.
That's especially true if he or she has long coughing spells that make your child turn red or purple, is vomiting or is accompanied by a whooping sound when your child breathes.