WASHINGTON — Montgomery County students aren’t the only ones exposed to whooping cough at a local summer camp. A Fairfax County boy has tested positive for pertussis, and more local families were notified that their children may have been exposed as well.

“He came home from camp with a cold,” says Dana Goldstein, mother of the 10-year- old Fairfax County boy. “The cold was a regular cold — sneezy, a little cough, runny nose. I didn’t think too much of it.”

But 10 days later, Goldstein says her son’s cough got much worse.

“He would go through bouts of it and gasp for breath at the end because he was just so exhausted,” she says.

He tested positive for pertussis this week and the entire family was prescribed antibiotics: “We sort of quarantined him in the house.”

Pertussis is a highly contagious respiratory infection that usually begins with a cold and develops into severe coughing fits. If doctors suspect a person is exposed to pertussis, they may prescribe medication immediately, even before the results come back. Those undergoing treatment for the bacterial infection can still be contagious for about five days.

At a recent Gesher Jewish Day School open house, where the boy attends, Goldstein says parents were surprised that her son tested positive for pertussis. “They had received the camp memo but were shocked that somebody had it from our area,” she says.

About a dozen students from the school — not including their siblings — attended the same camp session, which included third-grade students through college-aged counselors. WTOP obtained a copy of the email sent to parents on Monday from Rockville-based Capital Camps & Retreat Center. In it, the Pennsylvania Department of Health warns: “…your child may have been exposed to a person who was diagnosed with pertussis [whooping cough] at camp if he/she attended between 07/21/2014 – 08/10/2014.”

Jonah Geller, CEO of Rockville-based Capital Camps, says they were notified of a positive diagnosis nearly two weeks after the session ended and immediately started the process of notifying parents. “We were in constant communication with the Pennsylvania Department of Health from the very beginning of us learning of the information,” he told WTOP on Sunday. “They were helping and guiding us through communication with all of the families that had campers at our camping facility during our second session.”

The camp holds summer sessions in Waynesboro, Pennsylvania. About one thousand children, primarily from the D.C. area, attend the camp each summer. Geller estimates about 400 kids attended during the dates in question. As an accredited camp of the American Camp Association, all campers and staff are required to submit a complete medical form signed by a physician — including an immunization record — before attending Capital Camps programs. Goldstein’s son is vaccinated against pertussis and is scheduled for a booster shot soon.

Goldstein says the response was adequate and respected the families that were affected. However, “I might have wanted the information out there a little bit faster,” she says. “But maybe people weren’t as quick to recognize symptoms. I really don’t feel like anybody dropped the ball, but we all wish it wouldn’t have happened.”

Families must submit their child’s full immunization record before they leave for camp. Goldstein’s son is vaccinated against pertussis and is scheduled for a booster shot soon.

The CDC says the vaccine can lose effectiveness between regular vaccinations, but the risk of contracting pertussis is low to anyone who is immunized.

DTaP, the childhood vaccine, protects 80 to 90 percent of kids while Tdap, the adolescent vaccine, protects 7 out of 10 people.

More than 90 percent of Fairfax County Public Schools students are vaccinated against pertussis.

“The whooping cough cases across the country can be attributed largely to unvaccinated people,” Fairfax County Health Department spokesman Glen Barbour says. “This is why we strongly encourage everyone to stay up to date on all of their vaccines throughout their lifetimes.”

Virginia public schools require the Tdap booster vaccine for all rising sixth graders; school-required immunizations are free at the county health department.

Tdap is also available in Fairfax County, free for people aged 19 and older, who have never had a prior dose. Gesher Jewish Day School requires basic immunizations before kindergarten and before sixth grade.

Goldstein’s son was treated with antibiotics before testing positive on Friday.

Also on Friday, the Montgomery County Health Department said it was aware of three confirmed cases and nine suspected cases reported after children attended the same camp.

WTOP’s Mike Murillo contributed to this report.

Follow @WTOP on Twitter and WTOP on Facebook.