Or another question would reality already be lost if a being of that magnitude was infected? I do not think giving presents at your party proves anything. Lea got one and we know where that one ended.
I don't think Ferrofax is infected. Jim's purpose for the party was to introduce characters and to set up future story lines. Cowl and Kumori were there, apparently they had the Knife [infected] that Bianca presented to Lea, which lead to events we are now seeing.. Susan crashed the party, which led to her being half turned, which led to the down fall eventually of the Red Court and the birth of little Maggie. Thomas was present, push Susan toward the vamps to save Harry, saved the Sword of Love, which he returned to Harry, which led to him finding out he was his half brother. Mavra was introduced, and apparently she is behind a lot of stuff.. So of those mentioned, though he has made a couple of appearances we still don't know who or what Cowl and Kumori are and how they fit into the series. Mavra pops up also, but she is still rather vague and I wonder if she will be supplanted by Drakul now? Yeah, Ferrovax showed up in Peace Talks, but so what? It was rather meaningless, he and Vadderung gave each other dirty looks and exchanged a little toxic testosterone, but Ferrovax did nothing for the rest of the book and didn't make an apparence in Battle Ground. One wonders if Jim merely put him at the peace talks because of fans asking him questions and because he promised that he'd make an appearance later in the series?