Doesn't anyone realize there are no controls in a pandemic that is decades old? The virus/infection is everywhere.
No significant differences were found for any major DNA viruses between patients and controls using cell-free DNA from the blood. By using cell-free DNA it was possible to look for even the viruses that can hide behind the blood-brain barrier escaping detection by normal means. In addition, the blood of patients was examined for new pathogens by isolating particles from the blood and using DNA sequencing. No new pathogens were found