Updated at 6:35 p.m. CDT April 29

The Iowa Department of Public Health confirmed Friday that two ISU students have pertussis.

Pertussis, commonly known as whooping cough, is a highly contagious respiratory tract infection that causes persistent coughing followed by a whooping sound when the person gasps for air.

The two diagnosed students are being treated with antibiotic therapy.

Those who have been in close contact with the infected students are being contacted by the Story County Health Department so they can seek preventive treatment.

Marc Shulman, staff physician at Thielen Student Health Center, said that as of Friday no common link has been made between the two students.

The infected students’ names and addresses will not be released because of the Health Insurance Portability and Accountability Act, commonly known as HIPAA, which protects patient privacy.

“Since there is no vaccine for college-aged students, it’s something we have to watch for,” Shulman said.

The most obvious symptom of pertussis is hard coughing that sometimes results in vomiting. It can be spread when the infected person coughs, sneezes or speaks.

People in classes with an infected person should not worry because the disease is unlikely to spread to people who maintain a distance of three feet or more, according to Daily staff reports.

If a strong cough persists for more than two weeks, however, students should seek medical attention.

The last confirmed case of pertussis at Iowa State was in November 2004.