A year ago, there were 29 cases of whooping cough in Lake County. This year that figure has nearly tripled to 79 cases.
"People need to be aware. This is highly contagious," said Dr. Victor Plotkin, Lake County epidemiologist.
To combat the problem, Illinois students this fall will have to prove they have received a booster shot as part of their physical exam required in 6th and 9th grades or risk being kept out of school.
Symptoms include severe coughing attacks without an apparent cause. The illness usually lasts at least two weeks and can go on for several months. Doctors can treat it with antibiotics, but they are most effective when started early.
For infants and young children, extended periods of coughing can be a sign of whooping cough.
Whooping cough is spread through direct contact, often with shared eating utensils or dishes.
A vaccine nearly wiped out whooping cough years ago, but it has made a resurgence. Most children get the vaccine by the time they are four years old, although doctors say some parents opt not to vaccinate their children and in some cases the vaccine has failed to prevent it.
Most infants have no protection. YouTube videos show violent coughing fits can have babies grasping for air and can cause broken ribs.
"It can lead to other complications because the brain is deprived of oxygen," said Dr. Plotkin.
Whooping cough is making a resurgence in other states around the country as well.
In Washington state whooping cough is considered an epidemic with an 1000-percent increase in cases over a year ago. And it has claimed the lives of a number of infants like baby Kahlia who was less than a month old when she died.
"It's scary, and I don't want anyone else to have to lose their baby," her mother said.
Over the few decades or so, whooping cough has been cyclical. The numbers were up dramatically a few years ago, then back down and now they appear to be going up again.
Doctors say pertussis is preventable, and that's why the state is hoping to get it back under control by mandating those vaccinations for students.