Abnormal structures which appear within the cell nucleus, the cytoplasm, or both, during the course of virus multiplication. In general, the inclusion bodies are concerned with the developmental processes of the virus. In some virus infections, such as molluscum contagiosum, inclusion bodies may be simply masses of maturing virus particles. In other infections (herpes simplex), typical inclusion bodies do not appear until after the virus has multiplied. Such inclusions may be remnants of the process of virus multiplication.
The presence of inclusion bodies is often important in diagnosis. A cytoplasmic inclusion in nerve cells, the Negri body, is pathogenic for rabies. See also Rabies; Virus.
