The purpose of this research is to investigate the influence of nosocomical infection on epidemiology. The frequency of nosocomcal infection and the type of pathogens causing nosocomical infection were analyzed under following categories: the type of diseases, the type of pathogens, and the medical care units. In this study, the nosocomical infection data base of Chang Gung Children's Hospita from 1999 to 2003 was retrospectively analyzed by secondary data analysis.
