Multiple virus hypothesis

Multiple virus hypothesis considers that ME/CFS is triggered and continued as a result of the body's response following exposure to multiple viruses, especially herpesviruses.

In 2016, a study by Williams, et al, looked at lytic proteins produced during reactivation of the Epstein-Barr virus, in particular the deoxyuridine triphosphate nucleotidohydrolases (dUTPase), as key modulators of the host innate and adaptive immune responses. They considered "the possibility that two or more herpesviruses may act synergistically and that virus-encoded proteins, rather than the viruses themselves, may act as drivers of or contribute to the pathophysiological alterations observed in a subset of patients with ME/CFS."