<P> Cytopathic effect or cytopathogenic effect (abbreviated CPE) refers to structural changes in host cells that are caused by viral invasion . The infecting virus causes lysis of the host cell or when the cell dies without lysis due to an inability to reproduce . Both of these effects occur due to CPEs . If a virus causes these morphological changes in the host cell, it is said to be cytopathogenic . Common examples of CPE include rounding of the infected cell, fusion with adjacent cells to form syncytia, and the appearance of nuclear or cytoplasmic inclusion bodies . </P> <P> CPEs and other changes in cell morphology are only a few of the many effects by cytocidal viruses . When a cytocidal virus infects a permissive cell, the viruses kill the host cell through changes in cell morphology, in cell physiology, and the biosynthetic events that follow . These changes are necessary for efficient virus replication but at the expense of the host cell . </P>

Inclusion bodies formation of syncytia and change in cell shape are examples of