Autism on the rise in America.
300,000 Children in U.S. Found to Have Autism
By Shankar Vedantam
Washington Post Staff Writer
Friday, May 5, 2006; A09About 300,000 American children have been diagnosed as having autism, according to the first comprehensive national surveys of the developmental disorder.
Boys were four times more likely than girls to have the disorder, which is characterized by verbal, social and emotional problems. White families with higher incomes were also more likely to report having children with the disorder, a fact that federal experts said probably reflected unequal access to medical services.
The new data came in two surveys released yesterday by researchers at the Centers for Disease Control and Prevention, who said the numbers matched the range found by earlier studies that looked at smaller groups of people.
Autism has been dogged by controversy for more than a decade after what appeared to be a sharp increase in diagnoses in the 1990s. Many experts believe the increase reflects changes in diagnostic criteria adopted in 1994, increased public awareness of the problem, and the difficulties in telling apart a number of overlapping conditions that fall under an umbrella known as autism spectrum disorders. Some advocates have blamed a mercury-based preservative in children’s vaccines, even though repeated analyses have failed to confirm a link.
The new surveys show that Hispanics have a much lower autism rate than whites, but experts said that this probably reflected differences in access to care.
“This does provide important results on the need to consider autism may be under-diagnosed in certain populations,” said Laura Schieve, an epidemiologist at the National Center on Birth Defects and Developmental Disabilities, at a teleconference organized by the CDC.
Schieve and José Cordero, director of the birth defects center, said both surveys showed some differences in autism prevalence by age group — with children ages 6 to 11 more likely to be diagnosed than those ages 4 to 5. However, they said the differences were not statistically meaningful and could not address whether the decision to phase out the mercury-based preservative from children’s vaccines in 1999 had led to a leveling off or fall in autism diagnoses.
Cordero said it was far more likely that the age-group differences in prevalence reflected the fact that many children are not diagnosed until they enter school and teachers recognize the problem. That means the number of diagnoses among the 4-to-5-year-olds in the surveys could rise as they enter school.
“Let’s do it again next year and the year after,” said Gary Goldstein, president and CEO of the Kennedy Krieger Institute at Johns Hopkins University, which has a large autism research program. “My prediction is you are going to see a rise in the younger ones. If it was going away, which I would love, you would see a falling number.”
Goldstein said the racial and class differences in diagnoses reflected the fact that getting a diagnosis often requires that parents be effective advocates, at least in the years before children arrive in school.
“It’s not like leukemia or a broken bone where a diagnosis will be made no matter what your social class is,” said Goldstein, who is also a board member at Autism Speaks, an advocacy group focused on research and awareness. “You have to be an advocate.”
Peter Bell, chief executive of the Cure Autism Now Foundation, an advocacy group, said the fact that some children do not get diagnosed before they reach school is troubling. Early diagnoses, he said, allow for early interventions, which are more effective.
Two local researchers who have long claimed there is a link between the mercury additive thimerosal and autism said the CDC numbers suggest there is a connection. Mark and David Geier, a father-son team, said at the very least the CDC data showed a leveling off in autism diagnoses.
“In early 2003, we looked at a number of databases and how much mercury children were getting from their shots, and we said there is a causal relationship between thimerosal and autism,” David Geier said. “Thimerosal started to be removed in July 1999. We predicted the rates of autism would begin to decrease. What we are seeing is decreasing trends. It coincides with children getting less mercury in their shots.”
© 2006 The Washington Post Company
So which is it? Late diagnoses or thimerosal? I guess we’ll have to sit back and watch the debate rage on without any answers.
I for one, am still going to vaccinate my children against infectious diseases. Until the causal relationship between autism and vaccines is established or these diseases are eradicated, I don’t see how any parent could possibly delay or refuse vaccines with a clear conscience.
I once wrote a long tirade against people who chose not to vaccinate their child because it was the “worst” thing they could do – risk having their child being autistic. It’s been a long time since then, but I still feel that unless I am very much mistaken about the value of life, being dead is much worse than being on the autism spectrum.
In 1997, the National Childhood Encephalopathy Study (NCES) was examined to see if there was any link between measles vaccine and neurological events. The researchers found no indication that measles vaccine contributes to the development of long-term neurological damage, including educational and behavioral deficits (Miller et al., 1997).
A study by Gillberg and Heijbel (1998) examined the prevalence of autism in children born in Sweden from 1975-1984. There was no difference in the prevalence of autism among children born before the introduction of the MMR vaccine in Sweden and those born after the vaccine was introduced.
In 1999, the British Committee on Safety of Medicines convened a “Working Party on MMR Vaccine” to conduct a systematic review of reports of autism, gastrointestinal disease, and similar disorders after receipt of MMR or measles/rubella vaccine. It was concluded that the available information did not support the posited associations between MMR and autism and other disorders.
Taylor and colleagues (1999) studied 498 children with autism in the UK and found the age at which they were diagnosed was the same regardless of whether they received the MMR vaccine before or after 18 months of age or whether they were never vaccinated. Importantly, the first signs or diagnoses of autism were not more likely to occur within time periods following MMR vaccination than during other time periods. Also, there was no sudden increase in cases of autism after the introduction of MMR vaccine in the UK. Such a jump would have been expected if MMR vaccine was causing a substantial increase in autism.
Kaye and colleagues (2001) assessed the relationship between the risk of autism among children in the UK and MMR vaccine. Among a subgroup of boys aged 2-5 years, the risk of autism increased almost 4 fold from 1988 to 1993, while MMR vaccination coverage remained constant at approximately 95% over these same years.
Researchers in the U.S. found that among children born between 1980 and 1994 and enrolled in California kindergartens, there was a 373% relative increase in autism cases, though the relative increase in MMR vaccine coverage by the age of 24 months was only 14% (Dales et al., 2001). For more on this study, see California Data on Theory of Autism and MMR Immunization.
Researchers in the UK (Frombonne & Chakrabarti, 2001) conducted a study to test the idea that a new form, or “new variant,” of Inflammatory Bowel Disease (IBD) exists. This new variant IBD has been described as a combination of developmental regression and gastrointestinal symptoms occurring shortly after MMR immunization. Information on 96 children (95 immunized with MMR) who were born between 1992 and 1995 and were diagnosed with pervasive developmental disorder were compared with data from 2 groups of autistic patients (one group of 98 born before MMR was ever used and one group of 68 who were likely to have received MMR vaccine). No evidence was found to support a new syndrome of MMR-induced IBD/autism. For instance, the researchers found that there were no differences between vaccinated and unvaccinated groups with regard to when their parents first became concerned about their child’s development. Similarly, the rate of developmental regression reported in the vaccinated and unvaccinated groups was not different; therefore, there was no suggestion that developmental regression had increased in frequency since MMR was introduced. Of the 96 children in the first group, no inflammatory bowel disorder was reported. Furthermore, there was no association found between developmental regression and gastrointestinal symptoms.
Another group of researchers in the UK (Taylor et al., 2002) also examined whether MMR vaccination is associated with bowel problems and developmental regression in children with autism, looking for evidence of a “new variant” form of IBD/autism. The study included 278 cases of children with autism and 195 with atypical autism (cases with many of the features of childhood autism but not quite meeting the required criteria for that diagnosis, or with atypical features such as onset of symptoms after the age of 3 years). The cases included in this study were born between 1979 and 1998. The proportion of children with developmental regression or bowel symptoms did not change significantly from 1979 to 1988, a period which included the introduction of MMR vaccination in the UK in 1988. No significant difference was found in rates of bowel problems or regression in children who received the MMR vaccine before their parents became concerned about their development, compared with those who received it only after such concern and those who had not received the MMR vaccine. The findings provide no support for an MMR associated “new variant” form of autism and further evidence against involvement of MMR vaccine in autism.
Madsen et al. (2002) conducted a study of all children born in Denmark from January 1991 through December 1998. There were a total of 537,303 children in the study; 440,655 of the children were vaccinated with MMR and 96,648 were not. The researchers did not find a higher risk of autism in the vaccinated than in the unvaccinated group of children. Furthermore, there was no association between the age at time of vaccination, the amount of time that had passed since vaccination, or the date of vaccination and the development of any autistic disorder. Though there were many more vaccinated than unvaccinated children in the study group, the sample was large enough to contain more statistical power than other MMR and autism studies. Therefore, this study provides strong evidence against the hypothesis that MMR vaccination causes autism. — United States Centre for Disease Control and Prevention
Do you vaccinate your child? If you do, why? And if you don’t, why not?
This subject was exactly what got us started talking in the first place!
I think you get more mercury from eating fish! That said, if there are thimerosal free vaccines, I would go for that. The new 6-in-1 jabs are thimerosal free, according to the paed.
And have you heard of stories about almagam dental fillings and its effects on babies yet?
i understand that the only vaccine in question is mmr and i have known of people who are concerned to, therefore , take the mmr separately in 3 jabs similar to children who might have an allergy to eggs so as to reduce the risk to ASD.
forgot to add: u can also choose to delay it till abt 6 years old since mmr in singapore is known to be taken at 3. in my opinion, that’s a bit early and unstable. i vacinnated both my kids but did wait a couple of years.
Hsien > I know! It’s been a long time.
Angela > Yes, certain fish contain higher levels of mercury than others depending on where they are farmed. What stories about amalgam dental fillings? Do tell.
Rachel > The MMR is not the only vaccine that contains thimerosal, other vaccines such as certain ones for influenza do as well.
Tris blogged about amalgam fillings at Homely Scientist.
I believe many of the vaccines now don’t even use that preservative. Anyhow, I’m completely in agreement that it’s not serving the best interests of one’s child to delay or not ever vaccinate them.
I think some vague possible connection to autism is not a solid reason to wait until my child is 6 years old to have them protected against preventable diseases. “Sorry you can’t walk because of polio honey, but I was afraid you’d get autism”.
I generally avoid chatting about the topic, because I’m not very nice about it.
Deb > Oh I know what you mean; I’ve gotten into a scrap or two over this topic as well. Which is why I’ve learned not to respond on forums where people start ranting about how those who vaccinate their children are poisoning them, etc. It gets too illogical after a while!
Marvelous. Thanks, will spread this among my friends!