| Angiostrongylus cantonensis is a parasite which causes Angiostrongyliasis,which is the most common cause of eosinophilic meningitis.This parasite may become infected to human through ingestion of larvae by contaminated water, vegetables etc.The larva is then transported through the blood to the central nervous system, where they are the most common cause of eosinophilic meningitis.Eosinophilic meningitis is commonly defined by the increased number of eosinophils in the cerebrospinal fluid (CSF). 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. The impact factor of a journal is evaluated by dividing the number of current year citations to the source items published in that journal during the previous two years.