MARTINEZ -- There's been an increase in the number of confirmed cases of Pertussis -- more commonly known as Whooping Cough, at Morello Park Elementary School, and district officials are urging parents and guardians to take children to the doctor when coughs persist for more than two weeks.

In a letter sent to parents by the Martinez Unified School District Friday, Helen A. Rossi, director of Student Services and Secondary Support, said that all but two district campuses had reported confirmed cases of Pertussis, and despite parental vigilance, the number of cases is on the rise at Morello Park . She asked parents and guardians to notify the district if their child tests positive for the highly contagious lung disease.

Whooping Cough usually starts out like a common cold, with a runny nose and cough. As the cough persists and becomes more severe, patients can experience vomiting and coughing fits that make it hard to breathe, according to Contra Costa Health Services. The name comes from the characteristic "whooping" sound some sufferers make when coughing.

For more information about signs and symptoms, visit http://cchealth.org/pertussis. In her letter, Rossi also told parents who wanted more information to call the Contra Costa County Health Department at 925-313-6796 or the school district Health Services office at 925-335-5886.