Beware of mixing the following items:
1. Lectures on how the herpes viruses go latent in neurons.
2. A story by Gene Wolfe about alien birds that invade human bodies.
I had dreams about infinitesimal chicken pox birds nesting in my nervous system. It was not nice.
On the other hand, if you want to read a totally awesome and amazing story that may still give you uncomfortable dreams, may I suggest Roddy Doyle's "Blood"?