I just love being right. So anytime science vindicates me or my positions I will echo the findings. I recently posted about immunizations and the myths surrounding them. Years ago, some science journal decided to publish some poorly constructed study about autism and Thimerosal, an antiseptic additive used in vaccines to prevent bacterial contamination.
Some hack in the science world noticed that autism rates were increasing dramatically and he felt that this had to be related to immunizations, since our immunization rates have also gone up dramatically over the past several decades. His study was published in a British science journal and before too long it caught on in the US. Add a few celebrities and political names, ie RFK Jr, and soon the hysteria set in. Parents began withdrawing their children from immunization programs, and refusing very important vaccines out of fear of autism. Lawsuits and rumors of lawsuits began to build. The vaccine manufacturers began to panic.
Keep in mind that there have been many studies on this and some of those predated the study that induced all of this panic. Those studies showed thimerosal to be safe and not linked in any way to neurologic disease, including autism. Of course, science has never stopped people from taking drastic, irrational action (anyone remember what happended with DDT? How many people die every year from malaria since we banned it on bad science?). So the fear of lawsuits basically led the vaccine manufacturers to remove thimerosal from their vaccines in 1999 despite the lack of scientific evidence supporting such action. As a sidenote, this action alone could potentially be harmful since the reason for having thimerosal in the vaccine came about after several children died from a staph infection they received from a contaminated vial of vaccine. This didn't happen once the thimerosal was added. Granted, there are other ways to keep the vaccine clean, but still this was something that didn't have to be done given the actual evidence.
Anyway, the California Dept of Developmental Services has just completed a study that basically blows RFK Jr's cause completely out of the water and (hopefully) ends the discussion altogether. They've been tracking autism rates with close scrutiny since 1999 to see if there would be any impact from withdrawing the thimerosal. This is classic epidemiology. If a disease is caused by a particular agent, then removing that agent will lead to a decrease in the disease rate. So what did they find in California? Interestingly, the rate of autism has actually INCREASED since we stopped giving our children thimerosal in their vaccines.
Does this mean thimerosal provided an element of protection from autism? Of course not. But it does confirm the generally agreed upon theory regarding the increasing rates of autism. Basically, autism has increased because we have gotten better at screening for it, recognizing it, and diagnosing it properly. In the past, these children were simply labelled as "mentally retarded" because we didn't know much about autism. Now, we are diagnosing them appropriately. Plus, we have developed some screening tools to pick up on the diagnosis at younger and younger ages, and we are doing better at instructing parents on what signs to look for. So technically autism the disease is not increasing in frequency, but autism the diagnosis is. Make sense?
It is my sincere hope that this new study ends the discussion completely, and parents stop endangering their children with silly myths. But, somehow, I wouldn't be surprised if nothing changed.