Just this week health officials in Northern Kentucky say they've seen a 226% rise in the number of cases of one illness in their area.
Its an illness where there are usually only 18-34 reported all year.
Good Question: Why does it seem whooping cough is on the rise?
It's a sound no parent wants to hear, but its one that could signal a serious illness, whooping cough.
"It can be serious or life threatening in children or small children who either haven't been vaccinated or the vaccine hasn't taken effect, it can affect them where they can't breathe," said Dr. Jeff Foxx and Lexington family physician.
Whooping cough or pertussis is highly contagious and and spreads easily in places like schools where there is close contact.
Often times pertussis starts like a cold, but turns into a violent cough.
In the first half of the 20th century whooping cough was the leading cause of illness and death in children in the US, that is until a vaccine was introduced in the mid 70s.
In recent years though states like California, South Carolina, Texas, Ohio and Michigan have seen a dramatic increase in the number of cases.
Because of the of recent surge in cases, California declared an epidemic.
Now doctors worry that more cases are emerging because immunity is wearing off.
"We've seen some immunity wear off, we're vaccinating kids who get their vaccines and as you get older that immunity wears off, it may be the vaccines aren't working as well," said Dr. Foxx.
The Centers for Disease Control say the best way to prevent whooping cough is to get your child vaccinated, the same holds true doctors say for adults who often pass it along to their children.
"As an adult to get the booster there's a booster that now comes in with the tetanus booster called the T-Dat."
The CDC says protection from the childhood whooping cough vaccine starts to wear off after five to ten years.