So the viruses incorporated into our DNA are in fact fragments of viral DNA, typically from reverse transcriptases. The DRACO proteins recognizes double stranded RNA (dsRNA), while reverse transcriptases incorporate dsDNA into our genome, and then use our own DNA replication proteins to make more of themselves! Crafty! The upshot of this, though, is that there's no dsRNA in our genome, so nothing the DRACO could detect.

It's like we store our genome on DVD, and some viruses use CDs. They're very similar, but it's not the "content" the DRACO proteins are looking at, but the medium. We have no way to make CDs, only viral proteins can do that, so if the DRACO proteins see CDs, there's probably a virus about.