text: There are three types of viral infections that can be considered under the topic of viral transformation.  These are cytocidal, persistent, and transforming infections.  Cytocidal infections can cause fusion of adjacent cells, disruption of transport pathways including ions and other cell signals, disruption of DNA, RNA and protein synthesis, and nearly always leads to cell death.  Persistent infections involve viral material that lays dormant within a cell until activated by some stimulus.  This type of infection usually causes few obvious changes within the cell but can lead to long chronic diseases.  Transforming infections are also referred to as malignant transformation.  This infection causes a host cell to become malignant and can be either cytocidal (usually in the case of RNA viruses) or persistent (usually in the case of DNA viruses).  Cells with transforming infections undergo immortalization and inherit the genetic material to produce tumors.  Since the term cytocidal, or cytolytic, refers to cell death, these three infections are not mutually exclusive.  Many transforming infections by DNA tumor viruses are also cytocidal.
  Table 1: Cellular effects of viral infections
  Rounding of the cell<br/>
  Fusion with adjacent cells<br/>
  Appearance of inclusion bodies
  Inhibit DNA, RNA, and protein synthesis<br/>
  Interfere with sub-cellular interactions
  Insufficient movement of ions<br/>
  Formation of secondary messengers<br/>
  Activation of cellular cascades
  | Persistent ||
  Fusion with adjacent cells<br/>
  Appearance of inclusion bodies<br/>
  Budding
  Immune responses limit viral spread<br/>
  Antigen-antibody complexes can incorporate <br/>viral antigens causing inflammation
  Rare until stimulated
  | Transforming ||
  Unlimited cell replication
  Inactivates tumor suppressor proteins<br/>
  Impairs cell cycle regulation
  Unlimited cell replication