Each viruses have different mechanisms by which they produce disease in an organism, which largely depends on the viral species. Mechanisms at cell level primarily include cell lyses, the breaking open and subsequent death of the cell. In multicellular organisms, if enough cells die the whole organism will start to suffer the effects. Viruses cause disruption of healthy homestasis, resulting in disease, they may exist relatively harmlessly within an organism. Like on the disease herpes simplex virus, which causes cold sores, to remain in a dormant state within the human body. The latency and characteristic of the all herpes viruses including the Epstein Barr virus, which causes glandular fever, and the varicella zoster virus, which causes chicken pox.
Every people have been infected with at least one of these types of herpes virus. But this virus is latent that sometimes can be beneficial, as the presence of the virus can increase immunity against bacterial pathogens, such as “Ysrsinia Pestis.” While latent chickenpox infect can return in later life as the disease called shingles.
Several viruses can cause life-long or chromic infections, where the viruses continue to replicate in the body despite the host’s defence mechanism. Such as hepatitis B virus and hepatis C virus infection. The people who ever get this diseases called as carriers, as they serve as reservoirs of infections virus. In populations with a high proportion of carriers, the disease is said to be endemic.
