You're likely already infected with a brain-eating virus you've never heard of

You are almost certainly already infected with JC polyomavirus (JCPyV), a 'brain-eating' pathogen that silently persists in 50% of the adult population. This Ars Technica investigation reveals how JCPyV’s dormancy is recasting our understanding of neurological diseases like multiple sclerosis and brain cancers. The piece argues that the virus's lifelong residency is not benign—it may shape neural inflammation decades before symptoms emerge, a connection the average reader would never suspect.