An Ecological Framework of the Human Virome Provides Classification of Current Knowledge and Identifies Areas of Forthcoming Discovery

Parker, Michael T.

The characteristic strategy of persistent viruses is one of immune evasion and long term interaction with the host. Typically, these viruses exhibit mild and short-lived acute phase infections followed by establishment of a long term niche within a host. In this niche, the virus may go through stages of dormancy and reactivation, or slow replication for a long period of time [50] . This ability to progress to persistence for months, years, or the entire life of the host clearly delineates these viruses from the pathogenic viruses [51] . These relationships straddle the border somewhere between symbiosis and pathogenesis, traditionally making it difficult to classify them. In this context, I will typify long-term infections with well-described detriment to the host as persistent, and other longterm interactions as either commensal or mutualistic (see respective sections, below).