A total of three people at Montclair High School are reported to have tested positive for pertussis, or whooping cough.

Katya Wowk, the township communications director, said Wednesday that a third case at the school was reported on Monday, a week after the schools sent out a warning letter concerning two reported cases at the high school.

Wowk said that the nursing staff followed up with the patient’s family on Tuesday and that the case was reported to the New Jersey Department of Health.

On Feb. 6, Interim Superintendent Barbara Pinsak sent a letter to families informing them of the possible cases at the school.

“The intent is not to scare anyone but to inform,” Pinsak said at the Feb. 7 Board of Education meeting. She urged families to contact the district nurse if they had any concerns.

The letter did not specify whether the affected people were students or staff members.

The letter urged parents to keep their children at home if they showed any symptoms of pertussis. “We will continue to monitor the situation at school, and if additional actions to control the spread of pertussis become necessary, we will again notify parents/guardians,” the letter said.

Wowk said on Feb. 8 said that the Montclair Health Department was working with the schools on monitoring for new cases. “They’re on top of this,” Wowk said.

The precautions include making sure that the schools notify the health department if any students report to the school nurse with possible pertussis symptoms. The district staff is also required to notify the state health department as well.

Whooping cough is a respiratory disease caused by the spread of Bordatella pertussis, according to the Centers for Disease Control and Prevention.

In its early stages, pertussis may look similar to the common cold. The more severe symptoms don’t appear until later.

Symptoms of whooping cough in its advanced stages include violent fits of coughing, accompanied by whooping noises as the sufferer tries to take a deep breath. The disease is especially dangerous for babies and small children, who may be unable to cough.

The CDC maintains data on reported pertussis cases dating to 1922, when 107,473 cases were reported. The peak year after that was in 1934, when 265,269 cases were reported.

Cases of pertussis in the United States began to decline in the late 1940s, with the introduction of the DTP (diphtheria, tetanus and pertussis) vaccine. But the number of cases has gradually started to rise since the late 1990s. In 2012, a pertussis outbreak saw about 48,277 cases.

Today, there are two pertussis-related vaccines in use in the United States: DTaP, which is used for infants and children up to age 7, and Tdap, which is used for older children and adults.

The New Jersey Department of Health recommends a series of antibiotics for high-risk people who may have been exposed to pertussis, including infants, pregnant women and people with certain health conditions.

Anyone with questions is urged to contact the Montclair Health Department at 973-509-4970 or the Montclair Public Schools Office of Nursing Services at 973-509-4000, extension 6514, or visit the New Jersey Department of Health’s website at