When the Norton family of Laie left for a holiday vacation to visit relatives in Utah, they could not have the imagined the nightmare that lay ahead for their infant son, Gavin.

Two weeks after developing a cough on Dec. 26, the 10-week-old baby succumbed to pertussis, or whooping cough, a highly contagious respiratory tract infection.

Now parents Natalie and Richie Norton have turned their devastating loss into an urgent message for other parents, caregivers and anyone in close contact with infants about the importance of getting booster vaccinations to help protect themselves and reduce the risk of spreading pertussis to the most vulnerable.

According to the March of Dimes’ Sounds of Pertussis campaign, 80 percent of infant pertussis cases are transmitted from family members, primarily parents, who might not even know they are infected. The public education campaign notes that outbreaks have been reported all across the country this year. California is experiencing a statewide epidemic, with 1,337 cases, including five infant deaths, from January through June, a 418 percent increase from same period last year, according to the U.S. Centers for Disease Control and Prevention.

Hawaii health officials have not reported any outbreaks here, but they say the high volume of air traffic between the islands and California is a worry. There have been 37 cases of pertussis in Hawaii this year and 46 cases in all of 2009, said Marcia Nagao, acting program director with the state Department of Health’s Immunization Branch.

"Pertussis is contagious, but more severe in infants than older people," Nagao said. Infants also are at a higher risk for hospitalization or death from the illness.

Symptoms usually start within seven to 10 days after exposure. Nagao said that in early stages, symptoms of pertussis resemble those of a common cold: runny nose, sneezing, mild fever and a slight cough. After one to two weeks, the cough can worsen to the point where rapid and violent coughing pushes all the air out of the lungs, forcing the sick to inhale with a loud "whooping" sound.

At just 8 weeks old when he left with his family for Utah, Gavin hadn’t received his first immunization against pertussis. His mother, a wedding photographer, had taken him to a pediatrician to make sure he was strong enough to make the trip. The doctor gave Gavin a clean bill of health, and the Nortons departed for what they thought would be a happy family vacation.

When Gavin developed a persistent cough in Utah, they took their baby to a pediatrician who diagnosed him with bronchiolitis or the beginning stages of RSV (respiratory syncytial virus), a virus that infects the lungs and breathing passages. Both are common misdiagnoses for pertussis, especially in babies, who might have deceptively mild symptoms at first, according to the CDC.

Gavin’s condition worsened, and he was admitted to the pediatric intensive care unit at Primary Children’s Medical Center in Salt Lake City, where tests confirmed he had pertussis.

The Nortons watched helplessly as their son, connected to all manner of medical tubes and wires, continued to weaken. He died Jan. 7 as Natalie sang his favorite lullaby, "You Are My Sunshine" and Richie laid his hands on his son’s chest.

During the short period Gavin was ill, his mother made a plea for prayers on her online blog and received an overflow of support. She also was contacted by the Sounds of Pertussis, and Norton agreed to share her story to promote the public health campaign.

"I believe so strongly in what the Sounds of Pertussis campaign is doing," said Norton, whose other children are Raleigh, 7, Cardon, 5, and Lincoln, 4. Like so many other parents, Norton said she knew little about pertussis and was unaware of the need for adults to get a single booster shot.

"Doctors aren’t going to tell you; we need to take initiative," she said. "We can be the greatest danger to our kids. Make certain that your day-care providers, teachers, grandparents — anyone who comes into contact with your child — have been vaccinated."

Kaiser Permanente pediatrician Dr. Valerie Besenbruch said the pertussis vaccine is the best way to prevent getting the disease. Infants should be immunized with the DTaP (diphtheria and tetanus toxoids and acellular pertussis) vaccine five times from infancy through age 6.

Because a vaccine’s effectiveness fades over time, the CDC recommends another booster shot when children are 11 to 12 years old with Tdap, the adolescent and adult version of the vaccine. Older children and adults up to 64 years of age also should receive a single dose of the Tdap vaccine, the agency said.

"Usually in adults it’s not that big of a risk for dying (from pertussis), but a high risk for spreading it," Besenbruch said. "Vaccinate the people who live with (the baby)." Others in close contact with infants also should be immunized, she said.

"The vaccine is safe," Besenbruch said. The most common reaction reported by patients is mild pain in the area where the shot was administered. "That’s a small price to pay for not getting pertussis."