The average age of sick residents was 25, though many were in their teens.
Other regions in the state, including Utah County, are also seeing a spike in the disease despite the introduction of a new vaccine several years ago. Pulver knew newborns could die or experience major complications.
"It's disappointing to know other people aren't as vigilant about getting their immunizations," she said. "We still don't know who gave it to her."
The baby received antibiotics for a week along with the rest of the family. Now, 2-month-old Lauren is doing well. Pulver recommends that all adults make sure they're up to date on their vaccinations. She, her husband and their twins had been vaccinated before the baby got sick.
"We had everybody wash their hands and be careful around her, but you can't control if people feel like they're feeling sick and they still hold your baby," the mother said.
The vaccine is not 100 percent effective, explained Kevin Lash, a doctor with Wasatch Pediatrics. Another problem: Childhood immunizations wear off, so teens and adults need a booster.
"One of the good things is a lot of the moms are getting vaccinated in the hospital when they have their baby," he said. "We vaccinate parents and grandparents in the office too if they come in with a new baby and haven't been vaccinated."
Young children who catch pertussis can end up with pneumonia and need to be hospitalized. Seizures have been associated with the infection.
This winter's warm weather should be slowing the rate of infection, said Vitek, with the county health department. More people are outdoors and not clustered inside, where disease can easily spread.
Whooping cough spreads through respiratory droplets. The name comes from the deep, whooping breaths sick people take after violent coughing. Vaccination begins at 2 months and continues in multiple stages during childhood.
Whooping cough cases in Salt Lake County