Or rather, HPPD is caused by someone NOT being infected with the JC virus.
Ok, I'm not a doctor and all that, but you guys seem to like sharing theories on these things, so here is my theory (note: no science at all to back this up)!
http://en.wikipedia.org/wiki/JC_virus
The JC virus is very common in humans - it also causes persistent infection, where it is always present in the body, but unless you are immunosuppressed (e.g. AIDS) it doesn't cause any symptoms. It is normally completely benign.
This article;
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1617318/
states
Or rather, HPPD is caused by someone NOT being infected with the JC virus. Ok, I'm not a doctor and all that, but you guys seem to like sharing theories on these things, so here is my theory (note: no science at all to back this up)! http://en.wikipedia.org/wiki/JC_virus The JC virus is very common in humans - it also causes persistent infection, where it is always present in the body, but unless you are immunosuppressed (e.g. AIDS) it doesn't cause any symptoms. It is normally completely benign. This article; http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1617318/ states