Are their any attorneys who frequent this site? Powerful software such as Lexis Nexis could point us in the right direction... there should at least be a COD listed. Although, it might not be very helpful (heart failure, etc. instead of underlying cause)
I feel this is very important that it is followed up on. IMO if tissue results showed that the tests were negative, we would have heard about this. IMO information supression to avoid panic IS what is going on.