I am so sorry about the loss
of your dog. 16 plus years, is an amazing life for a large dog. It is a blessing when a dog lives a long life, and is able to die in the comfort of his own home, where he feels safe.
I do not know why you are worried about having touched your dog after he died....you touched him while he was alive, and you never contracted anything from him then, did you...?
I don't know where you read this, but I have never heard of such a thing.