The Boulder County Health Department has sent a warning to parents about an outbreak of Pertussis, also known as whooping cough, at Boulder High School.

Officials are warning parents to watch for symptoms such as a runny nose, sore throat and uncontrollable, violent coughing. They say the symptoms generally show up 7 to 10 days after the initial exposure.

The CDC says that the illness is much more likely to affect older children and adults. The reason is because most of us were immunized as children and the immunity decreases as we get older.

However, Pertussis can affect people of all ages and can be very serious, even deadly, for babies less than a year old.

The best way to protect against Pertussis is by getting vaccinated. The Boulder Health Department is asking students and faculty to see a doctor and stay home for 5 full days if you contract this highly contagious respiratory disease.

Source: CBS DENVER