The Mysterons resmebled one of the symptons of the Plague I think, the rings, apart from them moving. I'd suggest hearing voices is a pretty likely outcome of contracting the plague as well. Not sure Antibiotics would work on it, although I don't profess to be a Doctor. Either way, we should be quaranteening the CG and burning everyone within it, that or get a Puppett in Red to come and sort them out.
We need Alan Hansen....