BackgroundBack in November, 2005, David Kirby agreed with blogger Citizen Cain on the following:
If the total number of 3-5 year olds in the California DDS system has not declined by 2007, that would deal a severe blow to the autism-thimerosal hypothesis.
Let me emphasize that David Kirby also conceded that what matters is the total number of 3-5 year-olds, not changes in caseload growth. As I have argued, drops in caseload growth should be expected in the long run anyway.
DataWith one quarter to go before 2007, the latest quarterly report is out, as first blogged by Dad of Cameron. Please check out his graph of the 3-5 cohort caseload for the last 17 quarters.
Here's a table with some of the highlights from the last 4 quarters.
(False New Cases)
|Annual Growth (%)||3-5 Cohort|
The key information in Table 1 is that the 3-5 caseload continues to grow, and this growth is still rather fast compared to population growth in the state of California. Barring any miracles, in one quarter David Kirby will either need to issue a statement saying that he no longer believes in the autism-thimerosal hypothesis, further goalpost-shift the target date for a caseload drop, or claim that there hasn't really been a significant drop in the thimerosal dose per child in California. What do readers predict he will do?
It's a bit surprising that caseload growth has increased for at least the last 4 quarters in a row. Even when expressed as an annual percentage, it seems to be in an upward trend. As I've noted before, this might indicate that leveling off of the population (i.e. annual caseload growth matching California population growth of about 1%) is still very far away.
CDDS autism prevalence for the 3-5 cohort is currently about 40 in 10,000. This is not supposed to include PDD-NOS or Asperger's, but anecdotally it is known that diagnoses are changed in order to force eligibility in some cases.
Thimerosal HypothesisIt is important to understand what the "thimerosal hypothesis" is. Versions vary slightly, but let's take Mark Blaxill's one, as presented to the IOM in 2001. Blaxill indicated that mercury exposure from vaccines went from about 70 micrograms for the 1991 birth year cohort to about 180 micrograms for the 1994 birth year cohort, which coincided with an increase in the prevalence of autism for birth year cohorts between those years. That is, most or all of the prevalence increase during the "autism epidemic" of the 1990s can be attributed to an increase of the thimerosal dose per child, according to Blaxill.
Were Blaxill's hypothesis correct, if thimerosal exposure drops to levels below 70 micrograms, the 1990s epidemic of autism should be reversed. Even if you believe there are still traces of thimerosal in vaccines, and that children are still exposed to 25 micrograms of thimerosal from the Flu vaccine, it is clear that thimerosal exposure is no more than it was in 1991 and the entire 1970s and 1980s for that matter.
Note that the 3-5 CDDS autism caseload in Q2 1992 was 462. That is about 13 times less than what it is today. There is no denying such clear numbers. The only way to continue to believe in a hypothesis such as Blaxill's involves suspending reason. At this point we are simply waiting for the main proponents to come clean on that, provided intellectual honesty means something to them.