OMAHA — Cases of whooping cough have been on the rise in recent days.

The Douglas County Health Department has received reports of 48 cases of the respiratory ailment, also known as pertussis. A quarter of those cases came from one school.

Health Director Adi Pour says the department is working with school administrators and sent a letter home to parents to help control the spread of the illness.

Symptoms of whooping cough early on include sinus congestion, runny nose, a slight sore throat and possible low-grade fever. It can progress into violent coughing spells that can last for two weeks.

The illness is highly contagious and is spread when infected people cough or sneeze.