ARUN RATH, HOST:
Nearly 80 people in the United States are now confirmed to have measles, most of them with confirmed links to the outbreak that started at Disneyland and Disney's California Adventure Park. The California Department of Public Health was able to find vaccination records for some of the infected. They found that at least 28 had not received the measles vaccine.
Last April, we examined the state of the anti-vaccination movement, and turned to science writer, Seth Mnookin, who wrote a book about the vaccine-autism controversy. We called him again this week and started by playing back part of a conversation we had with him last year. In it, he told about an epidemiologist who would track where the anti-vaccine trend tends to cluster.
SETH MNOOKIN: And he said, sure, we just take out a map and put a pushpin everywhere there's a Whole Foods and draw a circle around that area. He was speaking slightly in jest, but what he was referring to is the fact that you do see a number of well-educated, politically liberal people who self-identify as being environmentally conscious.
RATH: So right now, we have an outbreak in Orange County, California, with cases in places like the Bay Area, Oregon, Washington State.
MNOOKIN: Yeah, those are actually exactly the types of communities that the epidemiologist I was talking to in that instance was referring to. These are all communities that have higher-than-average income, higher-than-average education levels. Their communities, for - unfortunately, where the idea that by not vaccinating your son - how doing something for your children has taken hold. And I think now, we're seeing some of the really, really scary effects of that.
RATH: So this is kind of what you were expecting, but is there anything that you've learned from this current outbreak in California?
MNOOKIN: I guess one heartening thing is that over the past couple of years, the vast majority of parents who do support vaccination and who do want their children and the people around them to be protected have realized that they really need to stand up and make their voices heard. For a long time, this was an issue where you would have really, really vocal anti-vaccine advocates, and then, the people who sort of supported the status quo didn't feel as compelled to make their voices heard.
But now we have a situation where, you know, you have hundreds of thousands of people potentially at risk. You have an enormous burden on the public health system. And you have whole populations of people - infants, anyone who's immunosuppressed, the elderly - who are not only vulnerable to measles infections, but if they do get infected, are likely to fare far worse than just having a trip to the hospital.
RATH: So with a number of cases growing to over 70 this week, how worried should we be?
MNOOKIN: Well, the thing about measles is it's the most infectious microbe known to humankind. If I was infected and I walked into a room and then left, you could get infected if you came into that room, even two hours later. It has a 90 percent transmission rate. So if you have measles and you're around 10 people who don't have measles but are vulnerable, nine of them will get infected. It's just incredible, incredible numbers.
And that's one of the reasons why public health officials get so anxious about measles and scramble so much to contain outbreaks. What we're seeing, now, in how these cases have multiplied over the past days and weeks. I think we're still, thankfully, not in a worst-case scenario, which is you get an infection in a community where you have a really, really high number of unvaccinated children, and all of a sudden, you know, from one day to the next, you go from 70 cases to 100 cases.
RATH: That's Seth Mnookin. His most recent book is called "The Panic Virus." Seth, thanks very much.
MNOOKIN: Yeah, thank you so much for having me. Transcript provided by NPR, Copyright NPR.