Friend's, I hope everyone is well, I am also very well by the grace of God of Allah.
This time I will write about the natural history of the disease.
The natural history of a disease is the process by which a disease develops in stages from its pre-existing condition to its recovery, disability or death. Each disease has its own unique to a natural history. However the natural history of disease comparises to phases,1) Pre-pathogenesis phases, 2) pathogenisis phases.
Pre-pathogenesis phases: this refers to the period preliminary to the the onest of diseases in man. During this phases man exposed to the ricks of disease. In this phases, agent, host and environment are in a isolution.
Pathogenisis phases: The pathogenisis phases begins with the the the entry of the disease agent in the susceptible women host. In this phases disease agent induces tissue and physiologic changes, the disease progresses through a period of incubation and later thought early and let pathogenesis. The final outcome of the disease may be to a recovery disability or death. The pathogenesis phases main daddy be modified by intervision measure SAS s immunization and chemotherapy.
The infection may be clinical or sabclinical, typical or atypical or the host may become a carrier with or without having developed a clinical disease as in the the case of diphtheria and poliomyelitis.
Agent is defined as a substance living or nonliving or a force to tangible or intangible, which may initiate or perpetuate a disease process. Desh concept states that in order for a disease process to occur, there must be a unique combination of event that is a harmful agent that comes into contact with a very mostly susceptible host in the proper environment.
Those three epidemiological factors (agent, host and environment) are commonly referred as the ecological for epidemiological triad.
Many thanks to everyone for reading my writing for so long, everyone will be fine.