ABSTRACT
This chapter provides a broad overview of the concepts of disease production by animal viruses. It is concerned with the medical aspects of virus infection, the interaction of the virus with living cells, and the outcome of this interaction leading to the disease state. In the case of mechanical transmission, no virus replication occurs in the insect host, whereas with biological transmission, virus replication also occurs in the insect and the susceptible host. Infections may be localized where virus replication occurs in a general area or organ where the infection first occurred with no spread of infectious agents or conversely, virus replication may occur at site of entry, and then disseminate via the lymphatics or the bloodstream to other organs. Latent viruses are found predominantly in the Herpetoviridae and Retroviridae families. Diseases resulting from virus infection are both unique and complex, based on the nature of the virus and the host’s response to the invading virus.
