Viral pathogenesis

Viral pathogenesis is the study of how biological viruses cause diseases in their target hosts, usually carried out at the cellular or molecular level. It is a specialized field of study in virology. Pathogenesis is a process in which an initial infection becomes a disease. Viral disease is the sum of the effects on the host caused by the replication of the virus and of the host's subsequent immune response. Viruses are able to initiate infection, disperse throughout the body, and replicate due to virulence characteristics. Mechanisms of pathogenesis of viral diseases include: implantation of the virus at the portal of entry, local replication, spread to target organs, and shedding of the virus into the environment. There are several factors that affect pathogenic mechanisms. Some of these factors include virulence characteristics of the virus that is infecting. In order to cause disease, the virus must overpower several inhibitory effects present in the host. Some of the inhibitory effects include distance, physical barriers, host defenses, and conflicting cellular susceptibilities. These inhibitory effects may differ among individuals and different races due to the inhibitory effects being genetically controlled. Viral pathogenesis is the study of how biological viruses cause diseases in their target hosts, usually carried out at the cellular or molecular level. It is a specialized field of study in virology. Pathogenesis is a process in which an initial infection becomes a disease. Viral disease is the sum of the effects on the host caused by the replication of the virus and of the host's subsequent immune response. Viruses are able to initiate infection, disperse throughout the body, and replicate due to virulence characteristics. Mechanisms of pathogenesis of viral diseases include: implantation of the virus at the portal of entry, local replication, spread to target organs, and shedding of the virus into the environment. There are several factors that affect pathogenic mechanisms. Some of these factors include virulence characteristics of the virus that is infecting. In order to cause disease, the virus must overpower several inhibitory effects present in the host. Some of the inhibitory effects include distance, physical barriers, host defenses, and conflicting cellular susceptibilities. These inhibitory effects may differ among individuals and different races due to the inhibitory effects being genetically controlled. Three requirements must be satisfied to ensure a successful infection of a host. There must be sufficient virus available to initiate the infection. Cells at the site of infection must be accessible, susceptible, and allow the virus to enter, and the host anti-viral defense systems must be ineffective or absent. There are several mechanisms that must occur for a viral disease to develop: