Pathogenesis is the development of disease, from the initial appearance of disease all the way to its end stages. It is a multi-factorial process which depends on the immune status of the host, the nature of the species or strain (virulence factors) and the number of organisms in the initial exposure. The study of pathogenesis is important for medical professionals, as it helps them identify and treat diseases. It is also part of the work of laboratory sciences who work on cures and treatments for diseases, as each stage of pathogenesis represents a potential possibility for interrupting the progression of the disease. High-impact journals are those considered to be highly influential in their respective fields. The impact factor of journal provides quantitative assessment tool for grading, evaluating, sorting and comparing journals of similar kind. It reflects the average number of citations to recent articles published in science and social science journals in a particular year or period, and is frequently used as a proxy for the relative importance of a journal within its field. It is first devised by Eugene Garfield, the founder of the Institute for Scientific Information.