New quarterly numbers are out in CA, which has the best tracking system for autism cases in the country.
The numbers are dropping.
According to the state data, 2002 was a record year for new autism diagnoses, with 3,259 cases. In 2003, the number of new cases slipped to 3,125. In 2004, the number was 3,074.
For the first half of 2005, there were 1,470 new cases, compared to 1,518 in the same period in 2004.
http://www.dds.ca.gov/FactsStats/quarterly.cfm
Why does this matter? More after the break.
Thimerosal began to be phased out of infant vaccines in 1999, so babies born in 1998 were the last, as a group, to get the full load of mercury which was many times over the EPA limit. The CA stats count 3 year olds and up, so the children now entering the system were born in 2002, when thimerosal exposure would have been not eliminated but significantly reduced.
If there had been a recall of thimerosal containing vaccines, or any oversight of whether drug companies actually stopped making and distributing TCVs in this country, we'd know more about the real thimerosal exposure of children in various birth years, but unfortunately none of that happened.
The CA stats only count cases of full-blown autism, as defined by the DSM-IV. None of the other spectrum disorders such as Asperger's or PDD are included. So there is no "expanded diagnostic criteria" argument to be made here.
Is the trend definitive proof that thimerosal was the causative agent in the autism epidemic? Not yet. But if the numbers continue to drop I think it will be.
PS. Many flu shots contain 25 mcg of thimerosal and are being pushed on infants and pregnant women. Boosters for older children and college students also contain the full load of thimerosal. If you decide to vaccinate your baby, insist on seeing the package insert that goes with that exact shot -- parents are still reporting finding TCVs on the shelves now. Research before you vaccinate, and insist on thimerosal-free vaccines.