MARIN COUNTY (KPIX 5) — Marin County has been hit by a recent spike in cases of pertussis, better known as whooping cough.

Marin County Health Department says there have been 241 confirmed cases of the sickness, which is the highest number the county’s seen in eight years.

“It’s bad. Luckily, my kids are vaccinated, but that doesn’t mean other kids aren’t at risk,” said Sampson Goff, a parent in the area.

The contagious respiratory infection primarily affects young children. Whooping cough starts out like a cold, but the bouts of coughing are much worse. Doctors say the bouts often leave kids gasping for air in between fits, hence that name.

“The problem with pertussis is when young babies are exposed, the effects can be very serious. In 2010, there was an outbreak of pertussis and ten infants died of pertussis that year,” said Dr. Matt Willi, Public Health Officer for Marin County.

The health department says almost every single school in the county has had at least one confirmed case of whooping cough. At Sir Francis Drake High School, 56 cases were confirmed.

“It’s probably been about half of the kids in each class,” said Sir Francis Drake sophomore Isaac Dorfmaan. “It’s been really common this year.”

The health department says any child with a confirmed case immediately gets sent home from school for three days and is put on antibiotics before notifying the child’s parents. The department says low vaccination rates in the county are partly to blame for the high number of cases.

Officials suggest parents keep a close eye on their kids’ coughs. If you hear that distinctive, high-pitched “whooping” sound, take your child to the doctor immediately.