DAVID GREENE, host:
In the past few years there's been an increase in a once-rare disease -pertussis. You may know it as whooping cough. Today, there are at least 25,000 cases in the U.S. A new study in the journal Pediatrics may explain why that number is so high. NPR's Patti Neighmond reports.
PATTI NEIGHMOND: Jason Glanz is a senior scientist at Kaiser Permanente's Institute for Health Research. He was interested in the consequences of not vaccinating children. He examined medical records of children between the ages of two months and 18 years who were patients at Kaiser Permanente Colorado between 1996 and 2007. Glanz looked at pertussis infection among the children. Then he looked at whether they were vaccinated.
Dr. JASON GLANZ (Senior Scientist, Kaiser Permanente Institute for Health Research): We found that children of parents who refused vaccines were more than 23 times more likely to be infected with pertussis than fully vaccinated children.
NEIGHMOND: A 23-fold increase, says Glanz, is huge. Pertussis is a bacterial infection of the lungs, which causes coughing so severe patients can vomit or break ribs. Coughing fits are typically followed by a sharp intake of air, causing the whoop sound, hence the nickname whooping cough. The vaccine is 98 percent effective in preventing the disease and despite all the scientific evidence proving safety, many parents remain worried. Glanz...
Dr. GLANZ: There's a lot of misinformation out there and it's easily accessible, and it's competing - it's competing with the doctor who these days doesn't have a lot of time to speak with the parents. When making these difficult decisions parents want more information so they seek alternate sources. And that's part of the problem. It's an uphill battle.
NEIGHMOND: Victoria Joy decided not to vaccinate her daughter against any childhood diseases after talking to a friend. But she says in making the decision she did consider certain questions posed by her pediatrician.
Ms. VICTORIA JOY: What if she contracts whooping cough? Are you able to be with her outside of school? Are you comfortable hearing your child is most likely going to be coughing for a few months and be in some discomfort? Do you have the resources to be able to be with that and to nurture her through an illness?
NEIGHMOND: Joy decided she could cope if her daughter got sick. Dr. Randy Bergen is a pediatric specialist in infectious disease. He says children who get infected with pertussis will get really sick but most will survive. The problem is, he says, some won't.
Dr. RANDY BERGEN (Pediatric Specialist): The state of California reports between 2001 and 2006, there were actually 24 deaths from pertussis. And all of those deaths occurred in infants who were under two months of age.
NEIGHMOND: Infants under two months aren't vaccinated against diphtheria, tetanus and pertussis, because they're immune systems can't yet respond. The vaccine series begins after two months of age.
Dr. BERGEN: So the only way that we can protect infants - those at their greatest risk of death from pertussis - is what we call cocooning, where we immunize and protect those around the infants.
NEIGHMOND: And Bergen says that's the nature of vaccines. They protect the individual but they also protect those who can't get the vaccine. Bergen says the trend not to vaccinate is ironically the result of vaccine success.
Dr. BERGEN: I'm old enough to have seen some of these entities and realize how deadly and severe they can be. But they are so infrequent now, in this country, because of the success of our vaccines that parents don't know about it.
NEIGHMOND: And the recent increase in cases of pertussis makes it clear these diseases can make a comeback.
Patti Neighmond, NPR News.
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